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Nasa Happily Reports the Earth Is Greener (goodnewsnetwork.org)
424 points by ph0rque on Feb 27, 2019 | hide | past | favorite | 178 comments



From what I understand, the increase in atmospheric carbon dioxide will have a massive greening effect on the Earth (plants love CO2). But it seems this fact is usually omitted so as not to complicate the intended message. I always found it ironic that the "eco" mode button in many cars is a leaf icon.


> plants love CO2

In artifical conditions in laboratory there is a significant effect, up to 20% when doubling pre-industrial CO2 concentration.

But, in practice for wild plants nitrogen quickly becomes the bottleneck, so the real gains are much smaller.

And even for farming plants (which have fertilizer providing additional nitrogen) the real gains diminish, and are more in 5-10% range. For some crops CO2 has very little effect at all (for example corn).

Additionally - crops grew with raised CO2 levels have less proteins and useful nutrients.

And then you have to factor in the harmful effects from global warming on crops (heat damage, dry soil, less farmland available) and the overall effect is likely negative.

https://www.scientificamerican.com/article/ask-the-experts-d...


Here's where a management that aims for diversity of plants comes in handy. If care is taken to plant the correct proportion of nitrogen-fixing plants, and other plants (such as comfrey) that will grow really deep roots to extract trace minerals, the nutrient density can be increased. There are techniques to increase the soil fertility with the correct selection of plants. There is a design science, permaculture, that takes all these factors into account.


That applies to farming, but not to nature. All current animals evolved with the amount of nutrients in plants on average now. If that changes quickly, they'll have a hard time adapting.


I believe in global warming with all my heart but just to be balanced the heat also gives you a longer growing season and let’s plants thrive in higher latitudes.

Edit funny the downvotes. I’m on your team guys! Just think we can’t ignore counter facts.


The length of the growing season is affected by many things, like rain, days below freezing, days above threshold temperatures, etc. It's not clear at all that warmer global temperatures means a longer growing season.


For crops that tolerate the extra heat. Those which don't will need to be grown further toward the poles, which will reduce the length of growing season.


Reseeding a field with a new crop is technology known since thousands of years.

I don't think there is any risk of areas reaching temperatures too hot for any plants?

> which will reduce the length of growing season

Why?


...because plants that are overheated can't grow. Depending on how overheated they get they may merely become stressed, or they can die. But plants also need temperatures, particularly soil temperatures, that rise above some minimum before they germinate. So you need a period when the soil temperature is high enough, but the air temp is not too high. Figuring out the length of that window is very complicated.

Corn, for instance, can't grow when the temp is over 104 or so (depending on cultivar) and dies when exposed to temps over 110 or so. It maximizes its growth rate at around 86 degrees.

So: if you have a summer month when temps are regularly over 104, that's not really a growing season for corn. Thus you have to try to plant earlier and harvest earlier, and the window when you can do that successfully may be considerable shorter than it would if the temp stayed below 104 during the summer.

So then you try to go closer to the poles. But -- depending on temperatures and a lot of other factors -- that may not be a totally satisfying solution either. Corn needs specific amounts of rain, which may or may not coincide with periods when the temperatures are good. It also needs large amounts of soil nitrogen, which may or may not be present in arctic soils, and if the plant doesn't have it growth is slowed. Corn also needs the soil temperature to be relatively high to germinate (above 50 degrees, again depending somewhat on cultivar). In arctic soils, it may take a while for the soil to warm up that much in the spring, and that may reduce your growing season. So how all the factors play out, and whether those factors result in a longer or shorter growing season, are intimately connected to exactly how the climate changes.

I've used corn as an example, but of course other crops and wild plants all rely on complicated, interconnected conditions to thrive. The specifics are a bit different for every plant.

It all depends. There are a lot of factors that we won't really know until people start trying to do it.


It may become hotter, but solar declination isn't going to change. Move towards the poles and the sun will have lower elevation, fewer hours of light, and the balance of seasons will change.

How much is enough to matter? Will the net effect be more or less than change from CO2 or temperature? You tell me. We seem to have a lot of unknowns.


Plants adapt. The ones that can tolerate the extra heat will survive better and therefore propagate more than plants that don't.


There are no teams. I have to say even the statement "I believe in global warming" is kind of problematic, because your faith isn't required for it to be real. It is a thing that is, not a thing that only exists in your head.


Just because you believe something doesn't make it a fact.

"Global warming" would be better named "wilder temperature swings" (which is why we hear the phrase "global climate change"). Larger temperature swings (colder winters, hotter summers, no real spring or fall seasons) are not good for growing crops.


The north, where a lot of the new greening will occur, also has shorter days as winter comes. How much longer could the growing seasons in the north get?


In the movie Interstellar, mildew was the straw that broke the camel‘s back for agriculture. From what I‘ve read, this can be a possibility if CO2 rises too high.


And it was somehow easier to move people and farms to a giant space station than to build climate controlled greenhouses on earth. But it looked stunning in the movie..


The space station was an arc traveling to the new planet they found.


People also got sick and died from dust particles, I guess the conjecture was that earth would soon become uninhabitable.


If the bottleneck changes from CO2 to Nitrogen, maybe plants will start adapting to get better at fixation, pushing that limit higher than the CO2 limit.


Plants don't really get better at fixing nitrogen. They get better at hosting symbiotic colonies of nitrogen-fixing microbes in their root systems.

It's splitting a hair, to be sure, but developing root nodules for hosting a nitrogen-fixer species is a lot easier than evolving all the biochemical precursors from scratch. Nitrogen fixation symbiosis may have evolved independently in plants at least three times. It would have been a big advantage from 460 to 380 Mya and then again, to a far lesser extent, from 240 to 160 Mya. Teredo shipworms also employ nitrogen-fixing symbionts, in their gill structures, as well as some termites, in their guts, but the latter only derive benefit in an extremely low-nitrogen environment.

Since atmospheric CO2 has dropped after the last peaks, some plant species failed to preserve that symbiosis. They would have an easier time getting it back, now that CO2 partial pressure is rising back to levels experienced in prior geological eras.

The ultimate bottleneck is likely to be iron or magnesium.


That kind of evolution takes a while.


This sounds like something the GMO industry would be working on already.


If you seeded an ecosystem with nitrogen supplements would it allow the plant life to grow at an accelerated rate and capture carbon?


You use ammonia to add nitrogen to crops. Making ammonia is an extremely energy intensive process that already contributes about 2-3% of global carbon emmissions. [1]

So you could spray ammonia everywhere to promote growth, but it's not clear that you'll offset the carbon emissions from making so much ammonia in the first place.

[1] https://m.phys.org/news/2018-07-electrochemically-produced-a...


Ahh that’s what I figured, too bad

nitrogen fixing cover crops is the way in agriculture I guess


we are already doing that aggressively to feed everyone, and we worry it might be hard to keep it up, as is.


Of course. I've seen people using the "when an ice melt in a glass, the glass doesn't overflow" argument. They can't see the ice on the land, the albedo effect, the salt concentration, the sea temperature, the gulf stream... If you make things complicated, the truth lose a lot of people to convenience.

That's something the geeks have still a hard time to understand. They won't convince anybody by being right. That's not how public opinion work.


Clearly increased plant growth due to higher CO2 concentrations are not stopping CO2 concentrations from spiking precipitously right now, because it's still spiking precipitously.

It's very small effect that would take enormous spans of time to make any significant difference. Also in order for those plants to grow faster and make a difference, there needs to be a significant amount of plants. So it's a marginal issue. If plants grow at (made up number) 2% faster due to higher CO2 concentrations, that doesn't help much if we've wiped out 90% of the plant biomass.


but TFA clearly says we haven't wiped out 90% of the plant biomass. It clearly says that there are more plants than there were 20 years ago, not less.

CO2 concentrations are growing at <1% pa (year on year - there are large variations between northern hemisphere summer/winter), so an additional 2% absorbing effect from an increasing number of plants is not insignificant.


As I said I was making up numbers. Given enough plants they will eventually sequester all the CO2 (if we let them). This effect would make that slightly more efficient, that's all. However the actual amount of plant matter sequestering the CO2, and what those plants are and how efficiently they work to do so, are likely to be a much more significant factors. Whatever those factors are though, we're talking about extremely long periods of time.


The fundamental problem is that humans are not plants. In 100 million years all the CO2 might become coal or oil again but humans won't be there to witness it.


No, not again. Coal came from plants in an era where microbes could not yet decompose plants.


Peat is the first step in forming coal. Peat still forms under the correct conditions, so coal can still be formed.

Conditions might be rarer, but the steps aren't solely reliant on the absence of microbes which now exist.


Don't forget to credit fungi too!


No more coal. Right now the only way carbon is permanently lost from the ecosystem is from ocean crustacean shells being lost to the bottom of the ocean. Interestingly enough, before humans started freeing carbon, the ecosystem was in a period of all time low for available carbon.


It's not a slam dunk that more CO2 == good for plants.

As per https://www.politico.com/agenda/story/2017/09/13/food-nutrie...

> As best scientists can tell, this is what happens: Rising CO2 revs up photosynthesis, the process that helps plants transform sunlight to food. This makes plants grow, but it also leads them to pack in more carbohydrates like glucose at the expense of other nutrients that we depend on, like protein, iron and zinc.


The GP is talking about a "greening effect" on the Earth due to CO^2, but the article you've linked to and this quote is talking about how the nutritional content of plants for human consumption might suffer with more CO^2.

Unless you think that the only thing that's "good for plants" is their suitability for being eaten by humans this seems like an unrelated issue.

The vast majority of the Earth's plant biomass isn't going to be eaten by humans. You're not going to nibble on the oak tree in your back yard, but increased CO^2 in the air will make it more efficient at sequestering carbon.

It's not going to be some amazing increase in perceived growth rate. The CO^2 level indoors is often 2-3x what it is outside, and people already grow plants in those conditions.


Green mass of the leafs is the captured carbon dioxide that doesn't contribute to a greenhouse effect. Even if all leafs will be oxidized in a year, it doesn't matter because new leafs will emerge. Though I'm not sure about actual green mass on the Earth and cannot compare it with mass of CO2 in athmosphere, maybe it is too small to have any effect.


An our challenge going forward is the long term sequestration of carbon, this will not help, as it will not capture the excess CO₂ released by humanity. If a significant part of this greening is farmland, there is of course also the CO₂ released through field work and harvesting to consider.


There's a good reason that the effect causing global warming is called the Greenhouse Effect, and CO2 a greenhouse gas. It comes from the use in greenhouses. The effect has been known for well over a century (which makes it all the more odd there's so much political resistance now to accept that this is happening).

And while more plants is certainly a nice thing, there's more to having a healthy planet than just having more plants, especially when it comes at the cost of melting ice caps and changing weather patterns, possibly leading to desertification and less plants in other places.

Although according to the article, this particular increase in greenery is mostly due to projects to plant more trees in Indian and China, and investments into agriculture. All of them good things that don't really need more CO2 in the atmosphere.


> it seems this fact is usually omitted so as not to complicate the intended message

Any time a group starts altering the facts like this, it just shows that they value their 'message' above the truth, and they lose all credibility.

Edit: Downvote = disagree, or people genuinely believe it's OK to lie to further your cause, I'm not sure what's more disturbing.


The fact is often omitted because people use it to erase the problem. Is it worth submerging a large area of Bangladesh for a very slight global increase in plant growth?

In particular there's a faction of people who use "CO2 is plant food" to argue that it cannot be harmful, that reduction efforts would be wrong, etc.


For me, the problem with your remark is that it's proposing some kind of alteration of message (lying, in essence) by "a group" which is not really identified, but might be "climate scientists" - but with no actual evidence.

And also, the whole discussion branch nearby on the greening effect of small increases in CO2 is really missing the point, and is completely ungrounded in any science. There is a whole literature out there on how significant this effect is relative to other effects of rising CO2! (Spoiler: it is not that significant.)


> For me, the problem with your remark is that it's proposing some kind of alteration of message (lying, in essence) by "a group" which is not really identified, but might be "climate scientists" - but with no actual evidence.

So you disagree with the grandparent post's statement that "But it seems this fact is usually omitted so as not to complicate the intended message."?

There are plenty of large, prominent climate activist groups making prominent public statements. I've never heard a single one of them discuss this aspect. (Contrast with scientific papers, many of which do mention it and which are not what we were talking about).


The place to start would be: https://science2017.globalchange.gov/chapter/10/

The key phrase you're looking for is: CO2 fertilization.


Activists often think it's okay to lie to advance their cause.


Well, obviously. Look at how many lies we take as fact in order to get through any modern discussion on politics and public policy.


It's also extra Co2 for parasites.


>this fact is usually omitted so as not to complicate the intended message.

That sounds a lot like intentionally misleading people.


The title says trees but I think it really means “greenness” from a satillite view. Reading around the bottom, while India and China have done substantial tree planting programs, it sounds like a large chunk of this may be driven by unsustainable use of farm land. I’m not clear on how their increased farm usage corresponds to greenness and whether that matters. Would be curious if anyone can chime in.


From the abstract of the study[1]:

> The greening in China is from forests (42%) and croplands (32%), but in India is mostly from croplands (82%) with minor contribution from forests (4.4%).

I can't comment on the sequestration effects of farms, though, beyond my ken.

[1] https://www.nature.com/articles/s41893-019-0220-7


The Chinese forest expansion is the most amazing piece of news I'd never heard of. https://www.sciencedirect.com/science/article/pii/S138993411...


To sequester, the carbon has to stay put, Crops are typically harvested annually fields are tilled and rotated so amortized, they will buffer a much smaller amount of carbon that cycles rapidly.


Ok, we've shortened the title above to preempt that ambiguity.


There is a lot of potential to sequester carbon in soil in farms: https://cgspace.cgiar.org/handle/10568/89405


All plants do contribute to carbon sequestration but yes it does not mean that they are polluting less with unregulated farming practices.


Regulations rarely target sustainability anyway. The only thing typically regulated is water rights and chemicals used.


> “When the greening of the Earth was first observed, we thought it was due to a warmer, wetter climate and fertilization from the added carbon dioxide in the atmosphere, leading to more leaf growth in northern forests, for instance. Now, with the MODIS data that lets us understand the phenomenon at really small scales, we see that humans are also contributing.”

That global warming may induce more agriculture, and forest growth, in the global North is something I'd like to learn more about. Anyone have any further reading to recommend?


I doubt anybody really knows.

It is well known that CO2 improves plants growth. It is also well known that plants grow better within a narrow band of temperatures.

Increasing both the CO2 contents of the atmosphere and Earth's temperature will have some complex results where on the places within that temperature band, plants grow slightly faster, on places that cross from too cold into the band plants grow much faster, and on places that cross from that band into too hot plants will grow much slower.

Also, solar incidence has a much larger effect than CO2 concentration, so the places with best growth rate can only cross into the too hot region, and polar places crossing into the good temperatures can't really compensate (besides, there isn't much area at the polar regions, unless you are talking about the hole Antarctic getting green).

And, anyway, water availability has a much larger effect than solar incidence, and this one is completely chaotic. So, good luck getting any conclusion.


These all seem like variables a robust computer model could account for, no?


Temperature is chaotic, but with a large predictable component. Except for black swans, a computer model can get on the ballpark, and the climatology people have many of them.

The specifics of how trees react to increase CO2 concentration varies from one species to the other. AFAIK, only a few species have been measured, thus the increase on rate of growth on that component is quite uncertain. That can be improved by empirical tests, that many specializations of science are currently working into. Of course, the big elephant in the room here is ocean plankton, that has a two sided relation with CO2, because it both participates on photosynthesis and increases ocean acidity. AFAIK, there is little known on how those react.

Solar incidence is completely predictable, and doesn't tell a good story for global warming.

And for humidity, I don't think there is any reliable model out there. None of those are my specialization, so I may be wrong, but I don't think we have anything nearly viable for predicting this one.


Yes, and then the model will give you some result, but you will never know if you are accurately accounting for reality in all its complexity. The more complex your model, the less likely you are to match reality precisely. To quote a cliche, the model is the map, not the territory.


Would need to be pretty fucking robust


It's kind of an obvious implication to there being more CO2 in the atmosphere. Plants like it. If it gets warmer at higher latitudes, there will also be more plants able to grow there.

There was a 200 page report on global warming from the 1980s on HN a few days ago which had several sections on this as upsides to global warming. I only read 50 pages of it, but it is a remarkably clear and level headed document.

https://news.ycombinator.com/item?id=19251316


One serious caveat about the "plants like more CO2" idea:

The increase in CO2 strongly disfavors slow-growing old groth and established ecosystems, and favors fast growing plants, which are typically invasive species that take over and destroy established ecosystems, and reduce biodiversity.

Per usual, the devil is in the details.


Read Matt Ridley’s lukewarmer argument.


have done so, and I like http://coyoteblog.com/coyote_blog/tag/global-warming, recommended by Megan McArdle.

In particular I'm interested agricultural and dense growth projections in the North (and South?). The above stuff covers this only in passing to my recollection.


What Rising CO2 Means for Global Food Security: http://co2coalition.org/wp-content/uploads/2019/02/Rising_CO...


The CO2 Coalition is a pseudoscientific climate denial organization.


Perhaps rather than an ad-hominem you can instead argue the point being made?


Okay, here's the thing: If you have plants with more or less CO2 under otherwise the same conditions you'll have more growth in the plants.

However that's not how the planet works. If you put more CO2 in the atmosphere you'll have for example rising sealevels and larger deserts (and probably more effects that diminish food production). You can't just pick a single effect of increased CO2 in isolation. (Except of course that's what the CO2 coalition does, because they chose to believe fairytales instead of science on climate change.)

This is just the obvious flaw in that argument. If you want the details and all the science there's a chapter on food security in the IPCC report: https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-Chap... It discusses potential yields as well.


ELI5: how will melting ice caps cause rising sea levels? Ice has higher volume than water it's made of, so the effect of ice melting should be sea level falling. At least that's the case of Arctic Sea, which is just this: frozen sea. Antarctic is different, because most of the ice is located on land, above the sea level. But then, shouldn't northern cap melting cancel out melting of the south one?


For floating ice, the mass of the ice is buoyantly supported by displacement of an equal mass of liquid water. As the SI units for mass were originally defined by the density of liquid water at STP, of 1 g/mL, when the ice melts, it supplies exactly as much volume as was previously displaced, so there is no change in level.

As it happens, seawater is denser than pure water, with a density averaging 1.088 g/mL, so if we were just talking about floating ice, 1 kg of floating ice would displace 1 kg of seawater, with a volume of 0.919 L, when the ice (mostly-pure water) melts, it supplies additional volume of 1 L, an increase of 8.8% over the submerged volume of the ice. This mixes with the saltwater to reduce salinity and lower the density, but the overall effect is a slight rise in water level.

Now forget about floating ice. Some ice is not floating. It rests upon surface rock. When it melts, 100% of its volume (eventually) flows down into the ocean. When land-ice melts, it has a far greater impact on sea level. But we only need to worry about land ice that rarely melts due to seasonal variation: ice found mainly in the glaciers and icepack on Greenland and Antarctica. Due to albedo and insulation effects, it is more difficult to melt land-ice than sea-ice, but it is indeed melting at rates unprecedented within the relatively short span of human observations.

(If a land-ice glacier calves an iceberg into the ocean, the immediate effect is to raise sea level by about 86% of the volume of the ice, with additional rise occurring as the ice melts.)


> At least that's the case of Arctic Sea, which is just this: frozen sea.

There's Greenland in north.

> But then, shouldn't northern cap melting cancel out melting of the south one?

Cancel out? Melting can't decrease water level, so I don't see how canceling out is possible.


Even if the poles were modeled as just ice cubes floating on water, then melting them would not decrease the sea level, as 1/12th volume of the ice would be above water. So even with this very simple model the South Pole has no way to compensate the north pole’s contribution.


I can appreciate the idea, but this attitude is why bullshit pervades.

If a person or group consistently advances bullshit, it eventually becomes a useful heuristic to dismiss that person's or group's ideas without consideration.

It takes more energy to argue against the bullshit than it does to advance it in the first place, so insisting on that argument hurts dialogue more than it helps.


Partial pressure of atmospheric CO2 is not the limiting factor in growth for most plants. Increasing CO2 concentration will therefore not have a linear effect.

CO2 is a gaseous fertilizer, providing carbon to plants. But anyone that has ever kept a garden, or even a potted plant, knows that plants also need water, plus nitrogen, phosphorous, and potassium (N-P-K). Hydroponics growers can add to that list [Mg++], [Ca++], [SO4--], [Fe++], [Mn++], [Zn++], [Cu++], [BO3---], [MoO4--], and [Cl-] ions, usually present in the soil that is not used in a hydroponics system.

So increasing CO2 has diminishing returns, until further increase results in no further plant growth.



The map is kind of misleading. It shows Kerala one of the greenest States in India as as the least green while states like Rajastan where you can find hardly any greenary is marked as most green.

Edit: I know it shows the % increase in greenary. What I meant is the "greenary" shown in the map actually has almost no correlation with the greenery in the real world. Looking the map and expecting Rajastan to be a green area would be a bad idea.


Doesn't the map show the trend? So it's not about how green it is but how mucher greener it's become over the last decade.


Yup. It shows the increase. But I think the way its portrayed is kind of misleading. Most people looking at the map who is not aware of Indian geography is going to think places like Rajastan now has a lot of greenery due to significance increase in greenary which is far from reality. Would love to know what all factors where taken into consideration for deciding the greenery increase.


Yes this color choice is misleading. It would have been better to have chosen blue to represent this increase.


The USA, EU and Mexico apparently also managed to increase leaf area significantly without any extensive greening initiatives. The larger version of the global map shows this clearly, even though it doesn't look noteworthy in the (somewhat ambiguously labeled "... Greening Due To Human Activity") bar chart:

https://www.nasa.gov/sites/default/files/thumbnails/image/gl...


https://www.nytimes.com/2018/07/30/science/climate-change-pl...

"Despite global greening, carbon dioxide levels have climbed over the past two centuries to levels not seen on Earth for millions of years. And the carbon dioxide we’ve injected into the atmosphere is already having major impacts across the planet."

The "global greening" effect, to the amount it can manifest itself, existed since the CO2 started to increase but we still see that the problems from higher CO2 increase and will get always bigger.

It won't save us from any problems made by global warming.


I kinda find it weird, though. Because we only know what prehistoric climate conditions were because of tree rings (and ice cores, but they're measuring different things).

So predicting future tree ring growth based on climate changes, when we estimate the historical climate based on tree ring growth, means we can make up any relationship we want.


That shows lack of understanding in purpose and use of the tree rings and it is not relevant to the topic. What I read from your statements is just that you don't understand how the past climates are scientifically reconstructed, and want to express the doubt in the results of all the work of all the scientist that agree (which is effectively all of them, minus the ones directly or indirectly funded by fossil fuel companies or motivated by political relations, if you have other impression, it's distorted by the intentional activity of said companies and political groups).

But we don't configure the current modeling systems at all using the "prehistoric" reconstructions, the models and the currently measured values are much more precise. The "prehistoric" reconstructions only give you something to compare the orders of magnitudes.

And comparing that, the warming is unprecedented. Which is not surprising giving that the humanity managed to extract and burn more then the half of all readily available oil from the Earth's crust in just 100 years.

That very oil in the crust is however a result of more than 4 billion of years of the Earth's existence.

If you’re reading this in some country like US, given that the average US car weights around 2 tonnes, your existence alone is probably responsible for the CO2 mass equivalent to the weight of 7–10 cars every year, and to the volume of CO2 which corresponds to the volume of more than 3000 cars.

And the CO2, even if it's invisible for us, is actually "black" for something important: it's blocking the part of the spectrum that would allow the Earth surface to cool off. That's how small concentrations of it, compared to some other stuff in the air, produce such a big effect.

The physics is simple and undeniable, and it's known that there will be always more problems caused by the growth of CO2 in the atmosphere which increases the surface temperature of the Earth.


> And the CO2, even if it's invisible for us, is actually "black" for something important: it's blocking the part of the spectrum that would allow the Earth surface to cool off. That's how small concentrations of it, compared to some other stuff in the air, produce such a big effect.

> The physics is simple and undeniable, and it's known that there will be always more problems caused by the growth of CO2 in the atmosphere which increases the surface temperature of the Earth.

Take a look at this graph of co2 vs temperature over a geological timescale: http://www.biocab.org/Geological_Timescale_op_712x534.jpg (from http://www.biocab.org/carbon_dioxide_geological_timescale.ht...)

From this, there doesn't seem to be any relationship at all and the co2 has been much higher during much of the history of earth. At the very least, you can't say that the relationship is simple.


Take a look at who constructed the graph you quoted:

http://citizenschallenge.blogspot.com/2012/10/nasif-s-nahle-...

Not a scientist.

Now... anybody who is really interested in the real geological history knows that even the continents "weren't there" where they are now, when we look long enough in the past. Not to mention that, for the old enough times, not even plants existed on the land!

https://en.wikipedia.org/wiki/Geological_history_of_Earth

In that context:

https://www.skepticalscience.com/co2-higher-in-past-intermed...

"However, until recently, CO2 levels during the late Ordovician were thought to be much greater than 3000 ppm which was problematic as the Earth experienced glacial conditions at this time. The CO2 data covering the late Ordovician is sparse with one data point in the CO2 proxy record close to this period - it has a value of 5600 ppm. Given that solar output was around 4% lower than current levels, CO2 would need to fall to 3000 ppm to permit glacial conditions."

"(Young 2009). Rock weathering removes CO2 from the atmosphere. The process also produces a particular isotope of strontium, washed down to the oceans via rivers. The ratio of strontium isotopes in sediment layers can be used to construct a proxy record of continental weathering activity. The strontium record shows that around the middle Ordovician, weatherability increased leading to an increased consumption of CO2. However, this was balanced by increased volcanic outgassing adding CO2 to the atmosphere. Around 446 million years ago, volcanic activity dropped while rock weathering remained high. This caused CO2 levels to fall below 3000 ppm, initiating cooling. It turns out falling CO2 levels was the cause of late Ordovician glaciation."

"So we see that comparisons of present day climate to periods 500 million years ago need to take into account that the sun was less active than now. What about times closer to home? The last time CO2 was similar to current levels was around 3 million years ago, during the Pliocene. Back then, CO2 levels remained at around 365 to 410 ppm for thousands of years. Arctic temperatures were 11 to 16°C warmer (Csank 2011). Global temperatures over this period is estimated to be 3 to 4°C warmer than pre-industrial temperatures. Sea levels were around 25 metres higher than current sea level (Dwyer 2008)."

You have to understand geology to be able to compare. If you don't, people with agenda will easily sell you worthless graphs. Worthless as in "CO2 was higher when there were no plants and animals on the land at all, just the naked rocks." Nice target you have.


Thanks for the info. I'm sorry, you were right, that was a bad source.

However, the rebuttal surprisingly leaves out a graph that directly shows temperature against glaciation, solar output and co2, but rather just talks about the comparison, without showing it. I don't find that particularly convincing of anything. Just because

> "Around 446 million years ago, volcanic activity dropped while rock weathering remained high."

it doesn't follow that

> "This caused CO2 levels to fall below 3000 ppm, initiating cooling. It turns out falling CO2 levels was the cause of late Ordovician glaciation.",

especially given that this simple graph of all 3 influences mentioned (sun output, glaciation, and co2 levels) against temperature isn't included. Do you know of a source that shows this?

> "So we see that comparisons of present day climate to periods 500 million years ago need to take into account that the sun was less active than now. What about times closer to home? The last time CO2 was similar to current levels was around 3 million years ago, during the Pliocene. Back then, CO2 levels remained at around 365 to 410 ppm for thousands of years. Arctic temperatures were 11 to 16°C warmer (Csank 2011). Global temperatures over this period is estimated to be 3 to 4°C warmer than pre-industrial temperatures. Sea levels were around 25 metres higher than current sea level (Dwyer 2008)."

Again, it's hard for me to take this seriously without seeing the comparison between the different forces that are identified against each other and temperature. It's like someone was peering at something through binoculars and said they saw an elephant. They offer as proof by stating, "I see a trunk, and a tail, and its tusks..", but they won't let you look through the binoculars yourself. (Also the Csank 2011 link gives a 404)

The best I could find was https://www.co2levels.org/, which if you click the buttons in the top left, can be massaged in displaying co2 vs temperature for the last 800k years. And even in this period there are a few the temperature decouples from the co2 levels and mostly the temperature rise precedes the rise in co2, which makes one think that co2 entering the atmosphere is a effect of climate rather than a cause.

> You have to understand geology to be able to compare. If you don't, people with agenda will easily sell you worthless graphs. Worthless as in "CO2 was higher when there were no plants and animals on the land at all, just the naked rocks." Nice target you have.

I'm not saying the earth was the same as before. Just that the idea is that co2 is causing irreversible warming and that's that, isn't supported very well by the evidence I've seen. At best what you have given me shows that the co2 causing warming isn't entirely disprovable.

I guess what I'm worried about is that the news often simplifies complex topics to, "it's a disaster!", or alternatively, "it's a hoax!" I don't think things are that simple, yet I haven't heard from anyone, scientist or no, that things are not either a "disaster" or a "hoax".


> Just that the idea is that co2 is causing irreversible warming and that's that, isn't supported very well by the evidence

But it is, it’s the topic of physics, not history. The historical remains are by nature very incomplete and geology is extremely relevant when you try to interpret the historical proxies, but all that doesn’t matter if you want to understand how warming works: physics is undeniable, and all effects are known and are part of the models:

https://www.bloomberg.com/graphics/2015-whats-warming-the-wo...

Once again: it doesn’t help to say “it was warmer n millions years ago” if the continents weren’t the same and there were no humans. Our civilisation depends on many very fine tuned balances.


> But it is, it’s the topic of physics, not history. The historical remains are by nature very incomplete and geology is extremely relevant when you try to interpret the historical proxies, but all that doesn’t matter if you want to understand how warming works: physics is undeniable, and all effects are known and are part of the models:

> https://www.bloomberg.com/graphics/2015-whats-warming-the-wo...

There are no sources in this link. There is nothing about physics in this link. It simply describes a bunch of other forces and declares they are not applicable, therefore co2 is the only thing left and it must be the culprit. Forgive me, but science isn't a game of "Clue". Putting up a bunch of straw men and tearing them down doesn't mean that "the butler must have done it with the wrench", or in this case, co2 must have increased the temperature.

And wasn't your link from the your last post primarily referring to the history of the earth as evidence of co2 production? So which is it? The case for undeniable physics, which you have not provided a link for, or from the evidence from geologic history, which you have abandoned.

In the same spirit as your link, here is Leonard Nimoy talking about Global Cooling from the 1970's: https://www.youtube.com/watch?v=ei-_SXLMMfo . It has about the same amount of evidence. You can also check out https://en.wikipedia.org/wiki/Global_cooling to see the history of this.

> Once again: it doesn’t help to say “it was warmer n millions years ago” if the continents weren’t the same and there were no humans. Our civilisation depends on many very fine tuned balances.

Where did I say that "it was warmer n millions years ago" proves that increased co2 is not going to increase the temperature? I'm just saying you haven't shown it will. You are vehemently asserting, times were different then, so all I can conjecture is that you mean that we can throw that data out. I don't necessarily think so, but I also don't think that doing so proves your point. I can't prove co2 hasn't increased the temperature, but it's difficult to prove a negative. To wit, maybe an extreme example, but I can't prove the earth wasn't created 4000 years ago as per the Christian Bible, yet that doesn't mean it's true.

I'm am saying that what you've shown doesn't prove that increased co2 is going to warm the earth to a significant degree, and the current situation isn't caused by other factors.

To that point, it shares all the hallmarks of mass hysteria. A single central idea is put into the public consciousness, and each and every event is then linked to that event.

I also ask you to respond point to point to what I've written rather than simply try and attack a single statement. I wish you'd have responded to what I wrote concerning the lack of transparency of your link from skepticalscience.com or the graph from co2levels.org. Why won't you address this?


> There are no sources in this link

Of course there is, in the very page:

“Researchers who study the Earth's climate create models to test their assumptions about the causes and trajectory of global warming. Around the world there are 28 or so research groups in more than a dozen countries who have written 61 climate models. Each takes a slightly different approach to the elements of the climate system, such as ice, oceans, or atmospheric chemistry.

The computer model that generated the results for this graphic is called "ModelE2," and was created by NASA's Goddard Institute for Space Studies (GISS), which has been a leader in climate projections for a generation. ModelE2 contains something on the order of 500,000 lines of code, and is run on a supercomputer at the NASA Center for Climate Simulation in Greenbelt, Maryland.”

“GISS produced the results shown here in 2012, as part of its contribution to an international climate-science research initiative called the Coupled Model Intercomparison Project Phase Five. Let's just call it "Phase-5." Phase-5 is designed both to see how well models replicate known climate history and to make projections about where the world’s temperature is headed. Initial results from Phase-5 were used in the 2013 scientific tome published by the Intergovernmental Panel on Climate Change.”

> The case for undeniable physics, which you have not provided a link for, or from the evidence from geologic history, which you have abandoned.

The link is the summary of what calculating which physical formulas gives, as I've quoted. It's you who "doubt" in the "tree rings" and I've given you the context: tree rings are just a small piece of he whole picture, and what we know, including the levels of confidence from that part of science is still good enough to have a good picture of what is happening and what has happened before. But once again: not any single historical proxy is directly used when the physical formulas are applied.

> In the same spirit as your link, here is Leonard Nimoy talking about Global Cooling

That's a joke, right? I'm presenting you the results of the NASA's best computer models, and you are giving me a link to... what actually? Since when are TV shows a proof for anything?

> I'm am saying that what you've shown doesn't prove that increased co2 is going to warm the earth to a significant degree, and the current situation isn't caused by other factors.

And what you are saying is simply untrue. What I've given you is the result of a lot of precise calculations using the physical formulas and the values obtained by all the scientific work we have. And nobody ever has found any meaningful error in the physics we use.

If you don't understand physics, I can imagine that it's hard to you to believe in something you simply don't understand, and I don't know your background to help you. What I can give you is a personal page maintained by one English PhD in Chemistry, Dr Jack Barrett, which was known as the "global warming skeptic" in the 90ties (you can Google his name, at the time the other person mentioned on his page was also active in "denying", this other guy was a reasonably famous face in Britain, but also uninformed at then). But then Barrett tried to learn the physical processes, relevant for climate, which he missed while pursuing his career in chemistry. And if you read his newer material, he is now completely convinced that the physics is absolutely valid and confirming the warming:

http://www.barrettbellamyclimate.com

Everybody who has enough knowledge to be able to check the formulas and who has enough integrity to admit what he didn't know, and who doesn't have some hidden agenda would have to come to the same conclusion. Read the pages on his site. It's the most honest outcome of a former "doubter" I know of. There are still some "old" page from the time when he "was not convinced" but if you are really interested in the formulas and science behind all this, you will find enough there, I believe he updated most of his site to that what he knows and understands now (edit: I've checked, he still just updates the "news" pages, i.e: http://www.barrettbellamyclimate.com/page4.htm and http://www.barrettbellamyclimate.com/page5.htm )

It's about the formulas and measurements. Note: I'm not saying "take that guy as a reference." I'm saying: he's the guy who didn't know enough but was willing to learn and made enough notes, so if you are actually interested in some formulas "for beginners" you can find them there. If you'd want something even "more serious"... you'd need at last university level material, which of course exists too...


> Of course there is, in the very page:

Those aren't sources.

>“Researchers who study the Earth's climate create models to test their assumptions about the causes and trajectory of global warming. Around the world there are 28 or so research groups in more than a dozen countries who have written 61 climate models. Each takes a slightly different approach to the elements of the climate system, such as ice, oceans, or atmospheric chemistry.

This isn't a source. You need to provide the actual studies, and point out where it proves that global warming is caused by co2, and have a coherent argument. Right now seem to be throwing everything but the kitchen sink at me in an attempt to win the argument.

> The computer model that generated the results for this graphic is called "ModelE2," and was created by NASA's Goddard Institute for Space Studies (GISS), which has been a leader in climate projections for a generation. ModelE2 contains something on the order of 500,000 lines of code, and is run on a supercomputer at the NASA Center for Climate Simulation in Greenbelt, Maryland.”

500,000 lines of code? Oh wow, then, must be accurate! NASA did it, must be correct, right? That's how you prove things, you get NASA to sign off on them.

> The link is the summary of what calculating which physical formulas gives, as I've quoted. It's you who "doubt" in the "tree rings" and I've given you the context: tree rings are just a small piece of he whole picture, and what we know, including the levels of confidence from that part of science is still good enough to have a good picture of what is happening and what has happened before. But once again: not any single historical proxy is directly used when the physical formulas are applied.

When did I ever say I doubted tree rings? All I'm saying is that I'm not sure that co2 is a significant cause of global warming.

> > In the same spirit as your link, here is Leonard Nimoy talking about Global Cooling

> That's a joke, right? I'm presenting you the results of the NASA's best computer models, and you are giving me a link to... what actually? Since when are TV shows a proof for anything?

Actually, you're right, it was a joke, but you missed the punchline. You give me a link of a news reporter trying to interpret and regurgitate what scientists say now, and I give you an actor doing the same for what scientists said in the 1970's. You don't see the similarities?

> If you don't understand physics, I can imagine that it's hard to you to believe in something you simply don't understand, and I don't know your background to help you.

I do understand some physics. And what I don't I'm willing to learn. Do you? Why is it that all you do is regurgitate quotes from websites, or give arguments of authority?

> It's about the formulas and measurements. Note: I'm not saying "take that guy as a reference." I'm saying: he's the guy who didn't know enough but was willing to learn and made enough notes, so if you are actually interested in some formulas "for beginners" you can find them there. If you'd want something even "more serious"... you'd need at last university level material, which of course exists too...

You still haven't addressed my concerns the lack of transparency of your link from skepticalscience.com. You also didn't address the graph from co2levels.org. I was hoping you knew or would be able to say why temperature increase precedes co2 rising in the graph from co2levels.org. I was hoping you'd be able to show the sun output, the glaciation, the co2 levels against temperature, so I can see the relationship between them. At this point, though, it seems you're not interested.

I thought I was talking to someone who knew what they were saying. You're telling me to read this guys entire website, but I know all I'll be left with a bunch of conflicting data and further questions, and probably still not have my questions answered.

The reason I was talking to you in the first place was that I thought you had some understanding. But by now, I'm pretty convinced, you don't.

Believe it or not, I'm on the fence about whether co2 is the primary cause of global warming or not. I simply was refuting the original poster's assertion that co2 being the primary cause of warming was basic physics and the relationship is undeniable. Talking to you, it seems that you don't know much about the topic, but instead believe that arguments from authority are good enough. You can't find information that directly answers my questions, but instead point to just reams and reams of data that has nothing to do with what I asked, along with snide comments (ex. me "doubting tree rings", although I never brought this up).

I'm on the side of "Question authority" and you seem to be on the side of "Accept authority". That's fine, but I'm not interested in taking conclusions as gospel simply because NASA says so, no matter how many models nor lines of code were used.


> I'm on the side of "Question authority" and you seem to be on the side of "Accept authority". That's fine, but I'm not interested in taking conclusions as gospel simply because NASA says so, no matter how many models nor lines of code were used.

I never said that. What I've said was:

> Everybody who has enough knowledge to be able to check the formulas and who has enough integrity to admit what he didn't know, and who doesn't have some hidden agenda would have to come to the same conclusion. Read the pages on his site.

So no, it's not easy. If you are able to check the formulas, you can see they are right. If you aren't, you can claim that "it's not enough" and it will of course never be enough because it demands certain capabilities of the reader. You have to go slowly, formula after formula, and do simplified calculations, for which you don't need a supercomputer.

Once you understand formulas, and you understand that they are right, you could say "OK but I'd like to know what the more precise calculations would bring, if I'd apply these formulas separately on every small point of the earth, and then see how the parameters dynamically change through the time." Note: You don't need that to verify the validity of the warming physics, you need that "only" to know how your part of the Earth would typically behave through the time, including all the oscillations, ups and downs.

Then you would have either to write one another model, just like 63 models written by the scientists worldwide. Or you'd simply understand "from the inside" how the existing models work, and be able to accept that what is presented on the Bloomberg page I've linked is real (because once you have enough knowledge of what is in the program you don't have to repeat every step to see that the results do follow from the calculations).

The scientific paper about the computing model used on the Bloomberg page was also linked on that same page:

https://pubs.giss.nasa.gov/abs/mi08910y.html

as well as the measurements:

https://data.giss.nasa.gov/gistemp/graphs_v3/

So you surely had enough references even before.

Like I've said, the physics is real and there are no errors. If you can't understand the physics, then you are unable to be able to "check" anybody. And the physics is not simple as pre-school math:

If you can't understand this:

http://www.barrettbellamyclimate.com/page20.htm http://www.barrettbellamyclimate.com/page21.htm

and this:

http://www.barrettbellamyclimate.com/page8.htm

just don't ask me anymore for the proofs, because you are either incapable or unwilling to work it through. You have to do a lot of work, if you haven't before, and based on what you answered up to now, it's effectively sure you haven't, otherwise you'd ask about some detail in some formula, if you missed only that.

That is if you want to work through the formulas. If you don't but you want to see everything worked through, the shortest version is the Bloomberg article I've given you, and the longest the IPCC (The Intergovernmental Panel on Climate Change) report:

http://www.climatechange2013.org/images/report/WG1AR5_ALL_FI...

https://archive.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR...

https://archive.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR...

https://archive.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_w...

https://archive.ipcc.ch/pdf/assessment-report/ar5/syr/SYR_AR...

(all from: https://archive.ipcc.ch/report/ar5/ )

In the IPCC is effectively the summary of everything all the world scientists know about the topics, together, the result of the consensus of all the world scientists qualified enough to be able to work on the topics. It's long and complex, and long exactly because it addresses many different details.

And all that is full of references (which aren't lacking on the pages of the former skeptic too). So you can work through it as much as you want. Don't trust, check the formulas, really go through them yourself. The former skeptic did it too (he had the background in spectroscopy, luckily for him) . I've done it, I've did go through the points for which I didn't accept "it is said it's so" (and I, luckily for me, have enough background in physics). Every student of these sciences does it, every year the new ones. It is doable.


>> I'm on the side of "Question authority" and you seem to be on the side of "Accept authority". That's fine, but I'm not interested in taking conclusions as gospel simply because NASA says so, no matter how many models nor lines of code were used.

> I never said that.

You did quote bloomberg "ModelE2 contains something on the order of 500,000 lines of code, and is run on a supercomputer at the NASA Center for Climate Simulation in Greenbelt, Maryland." that line. If you don't think it was important, why quote it to me? Maybe I was misinterpreting you, but..

> What I've said was:

>> Everybody who has enough knowledge to be able to check the formulas and who has enough integrity to admit what he didn't know, and who doesn't have some hidden agenda would have to come to the same conclusion. Read the pages on his site.

Everybody with enough knowledge has to come to the same conclusion, huh? That's a lot of hubris.

> If you can't understand this:

> http://www.barrettbellamyclimate.com/page20.htm http://www.barrettbellamyclimate.com/page21.htm

> and this:

> http://www.barrettbellamyclimate.com/page8.htm

> just don't ask me anymore for the proofs,

I read through these, and I do understand them.

Basically "http://www.barrettbellamyclimate.com/page8.htm" is modeling a outside radiation source penetrating an outer atmosphere layer which allows 100% of it go through it. Then the earth radiates back to the layer which absorbs and reemits it, half back to earth, and half into space. The forces have to be in balance for the temperature average to stay in equilibrium. The conclusion is that the absorption/emission of the atmosphere at 0% would mean the earth would be a lot cooler 253K, and at 100% would be a lot hotter, 302K, so it must be somewhere inbetween. Therefore there is a greenhouse effect.

I never argued against the fact that there is a greenhouse effect, so although interesting, I don't see how it affects anything at all.

I looked at the other two links from that site, and see that co2 blocks a certain wavenumber band. Fine.

Lets take a look at page 28, however: http://www.barrettbellamyclimate.com/page28.htm

"The intention is to show the logarithmic nature of the relationship between CO2 and surface temperature, i.e., the temperature rises non-linearly with every successive addition of CO2 causing smaller effects. "

So here is the answer to something I suspected. The amount of co2 in the air becomes saturated at greater amounts. If you look at the graph, from 400ppm today, it will take up to 1000 ppm of co2 to increase the temperature effect as from 200ppm to 400ppm. So for we're only talking about a degree or two.

I think that scientists have made a lot of progress modeling the atmosphere because its so simple but the rest of the earth is much more complex and their models are, to put it bluntly, crap. The author agrees with me:

From http://www.barrettbellamyclimate.com/page48.htm :

"There is an absence of nits to pick in the physics of the greenhouse effect, but there are many incorporated in the various models. The fact that the twenty or so models all claiming to incorporate the same physics produce different results for temperature changes, cloud cover and rainfall indicates that something is wrong. These are early days in the development of climate models and it is expected that they will become more believable in the future. "

So what seems to be happening is that because they have this small effect from co2 modeled pretty well, and since it's not enough to explain the larger fluctuations of temperature through earths history, they try and find a way to make it seem as a lever to affect a larger change. I think they are subconsciously doing this... since it is the path of least resistance to finding an interesting, measurable formula by incorporating another rock solid one into it.

I also found an answer to my same question on that page about why temperature seems to precede co2 increases, not the other way around for the last 800k years at least, from co2levels.org . You've been ignoring me on this point for 3 replies now, so I doubt you'll respond, but just to let you know:

"Our comment: There is considerable misunderstanding of the ice-core records that do show that ~800 years after a temperature rise following an ice-age the concentration of CO2 increases. Not even the possibly exaggerated general circulation models can explain the ending of an ice-age by the appearance of large amounts of CO2. They end by various possible mechanisms. A change in the Earth’s orbital characteristics might increase the value of solar input to the Earth. Volcanic activity could deposit material on the snow/ice coverage that alters the planet’s albedo; the fraction of solar radiation reflected by the system. If this is the case the planet would warm up and this would have the consequence of releasing CO2 from the oceans and increasing the amount of water vapour in the lower atmosphere. This would, in consequence warm the system by the greenhouse effect and release more CO2 and water vapour… "

So the author explains it away with volcanos, sun spots and earths distance from the sun. Hmm... sounds a little vague for such large fluctuations, don't you think? Could it possibly be, that even with their complex and conflicting models, scientists don't actually know what caused these fluctuations back then? And further, that a small change in temperature due to co2 does not have a lever effect causing the larger change needed for these disastrous predictions? I suppose it so.

Now, couple that with all the "adjustments" to historical temperature data. Yes, they have excuses, measurements being taken at different times of day from before, older inaccurate equipment, change of environment, etc. I'd accept that if they changed it a couple of times, but they seem to have done it a lot. And there are a lot of other suspicious stuff going on. Why is there a temperature station now between the runways of a heavy trafficked airport (see the first link)?

https://notalotofpeopleknowthat.wordpress.com/2018/01/25/new... https://www.cnsnews.com/news/article/barbara-hollingsworth/g... https://wattsupwiththat.com/2014/08/23/australian-met-office... https://realclimatescience.com/2017/01/systematic-destructio...

Call me a conspiracy theorist if you like, but the temptation is there. Along with the general attitude of trying to suppress skeptics by the liberal media, liberal college bias and liberal institutions.

Anyway, barretbellamyclimate.com is a lot better than I first thought. So thank you for that.

I don't know why you think I need to understand the models that are not predictive in order to form an opinion. I will go through the rest of that site, but I don't think I need to delve deeper into theory that creates models that conflict with each other in order to form opinion on the predictions of the scientists who use those models as their basis.


> Anyway, barretbellamyclimate.com is a lot better than I first thought.

So you do understand some physics at least. Then...

Buy his book, and try to find any error: he confirms there that IPCC is right:

https://www.amazon.com/Global-Warming-Contribution-Jack-Barr...

It's less than 200 pages, much less than IPCC report, and also concluded without the use of the supercomputers. Human released CO2 is what is warming the Earth right now, at least at the speed as calculated by Intergovernmental Panel on Climate Change. Exactly what I've told you that anybody who honestly approaches the topic should do.

Prove yourself that you don't listen to authority, especially not Watts authority who is effectively a liar and the authority only to those who want to delude themselves or the others and who you obviously read.

You saw yourself what was Barrett's starting point on the pages that you like. You delightfully quote what he wrote before he checked everything himself. Then see how he was able to come to the conclusion that IPCC is actually right. There's no error: he was just able to repeat what the whole world can repeat and repeats everywhere every day... except the people who read Watts and such, which blocks them to see for themselves that IPCC is indeed right.

I already understood it is against your political sympathies to say that IPCC calculations is right. Well... it's time to prove that you don't listen to "authorities." You can confirm yourself and still have the political sympathies that you have. I definitely do not consider any of the two big parties or their voters even behaving consistently sane, but believe that in some topics one are right, in some topic another, and in some topics even neither. You are allowed to do that too. That can be a better chance for a real change, different than the pre-election slogan pseudo-change.

Don't support scientific illiteracy.

And most important: don't run searching for the false instant excuses by watts et al, search for the real sources yourself, check yourself what is real. Then once you are yourself sure compare what you've learned with what watts writes... and it will finally click how he distorts the truth. I don't care what his motivation is, his goals don't justify his means.


Past climates are scientifically reconstructed from data recovered from physical objects that were present during those climates. One of the main sources, if not the main source, for that data is tree rings from old wood.

If this statement is untrue, in any way, then please correct me, because yes, I've misunderstood how past climates are scientifically reconstructed. But I'm going to need you to explain what data is used during their reconstruction (and not some hand-wavy "it's very difficult and not for non-climate-scientists to understand").


Tree rings are absolutely used as a proxy to infer the past, the science is called dendrochronology, and the application of it is called

https://en.wikipedia.org/wiki/Dendroclimatology

The limitations of it are known, and you won't find that the results of it are used for false claims by the real scientists:

https://www.ipcc.ch/site/assets/uploads/2018/02/WG1AR5_Chapt...

What I'm posting above is the real report by the The Intergovernmental Panel on Climate Change. If you look in the context, tree rings are just one piece of the big and complex picture. See my other comment for an example how those who just try to confuse simply ignore (and don't even care for) geological facts when they try to push their agenda. The same happens with those who try to sell you the doubt and false claims about the state of climate research. The scientifically known uncertainties in using the tree rings as proxies aren't changing any facts about the reality of global warming.

It's undeniable basic physics. CO2 makes the Earth surface warmer because it blocks the part of the spectrum that would otherwise allow it to cool off. The part of the spectrum of the Sun that warms the surface up is however not blocked by the CO2. So the Earth gets the same effect that you have when you cover yourself with a blanket. It's warmer under it. It's undeniable and we are observing the effects every day:

https://tidesandcurrents.noaa.gov/publications/techrpt83_Glo...

If we don't do anything the expected sea rise on US shores is estimated up to 2.5 m higher (8 feet) in 2100. The non-red lines in the graphs are for the scenarios if the humanity actually stops pushing CO2 in the atmosphere very soon. We're already not following the "blue" strategies.


...more then the half of all readily available oil from the Earth's crust in just 100 years.

We've been hearing this Peak Oil crap for years. Maybe eventually it will be true...


Thanks for the good newss, didn’t know about that. News tend to be biased towards the bad and the good is left it. Bookmarking that site


I wouldn’t bookmark this site. The writers of this article did not do their due diligence in their research or in their presentation of this article. Check our the other comments here, which do a good job of explaining the nuances of the “greening”.


Skepticism is always good, but so is a modicum of good news bias, especially if announced, to counter the predominance of bad news bias.

If the world was in fact getting less green, and this was presented as bad news, would you hold the reporters to the same high standard of including all relevant silver linings?


It's greener because the vegetation is capturing some of our massive CO2 emissions, but the planet (or the biosphere, more precisely) is increasingly suffering from the Anthropocene: the ocean is slowly being killed, the soil is getting ravaged, insects are disappearing, birds too, the biodiversity is collapsing, etc.

A greener Earth is not a good sign. It's a swan song :'(


So when it has hotter previously in history it wasn't a good sign either? Not sure I understand why it's bad this time around and wasn't bad last time around?


Rate of change is the super scary part.


The rate of change of emission is not the same as rate of change of temperature so not sure what it is you are worried about exactly. Keep in mind the models aren't actual predictions they are models which give us a range from no problem at all to really scary. But none of them are actual scientific predictions and there is plenty of argument for why it's not going to be a big issue and certainly not something we can't deal with.


Apparently the earth was super green when the atmosphere had double the current CO2 content https://www.youtube.com/watch?v=gdfWFDcXut4


And why not, photosynthesis requires CO2.


The China government has been working on tree planting project for decades, which contributes 42% forest greening.


Serious question from a non-climate scientist: would an increase in global temperatures due to climate change ultimately cause more greenery, due to new growth in previously too-cold areas?


Well, I don't know about temperature, but we do know that plants grow faster in the presence of excessive CO2. But that's a double-edged sword, because their nutritional value per unit mass goes down, in terms of trace nutrients - with abundant CO2, they can use more air to build more empty carbs, but that means the critical nutrients they pull from the soil are present in lower concentrations.


You can easily see this effect on Highways (in Europe where trees are planted just at the edge of the road). The trees there are the first ones that turn green (and get greener much faster) while the trees in the farmland are still without leaves.


I wonder if that’s due to CO2 levels, warmer temperatures (asphault captures a lot of heat) or human selection for “pretty” trees along the highway.


I think that eco-systems do move to higher latitudes when the earth warms. This happened e.g. at the transition from ice ages. However the problem is that if the rate of warming is too high, eco-systems will not be able spread and adapt fast enough, leading to a net loss of bio-mass.

See e.g. page 3 of https://www.pnas.org/content/pnas/115/33/8252.full.pdf on biogeophysical feedback.

I am afraid the warming rate anticipated currently is at least an order of magnitude higher than any climate changes the earth faced before.


There is less surface around the poles, and previously ok-hot areas at the equator are now likely to become too-hot areas, so it's a net loss in this simple model.

A slightly more nuanced discussion upthread here: https://news.ycombinator.com/item?id=19263836


Most climate models take that into account, from what I've heard. It's not enough to mitigate the rising temperatures, though.


Also need to factor in the too-warm, too-dry and on-fire areas.


it's a bit of a double edged sword. warmer springs are definitely a good thing for plants in terms of growth. but in the united states, at least, there is evidence that the positive effect of warmer springs will be offset by drier, hotter summers that are not ideal for growth.

here is a discussion of a neat study in 2016 that showed this effect: https://www.pnas.org/content/113/21/5768

the already warm tropics are expected to get even warmer, which likely isn't great for the forests there.


Yes. But things like permafrost melting could release massive amounts of methane and CO2 to have a net opposite effect at least for the first decades / centuries.


Another question on the same lines - wouldn't the increase in carbon dioxide also contribute to increased greenery? I guess the more pertinent question would be what amount of greenery could have a reasonable chance at halting the adverse effects of human activities?


> It’s called the Moderate Resolution Imaging Spectroradiometer, or MODIS, and its high-resolution data provides very accurate information

So is the resolution high or moderate?


This is a fun question, and as an occasional user of MODIS products, I've asked it (to myself) also. Although I've never asked anyone on the MODIS team, who I see from time to time.

I have always supposed that they wanted to leave the door open for actual high (spatial) resolution observations in the future. The driving design requirement was for global coverage every two days, so this meant a wide field of view of the downward-looking optics (2200 km wide FOV) which in turn meant "moderate" spatial resolution.

It was designed in the early 1990s. If you look at the original MODIS design papers (e.g., The Moderate Resolution Imaging Spectrometer (MODIS) Science and Data System Requirements, IEEE TGARS, Jan. 1991), you read the design was inspired by instruments like AVHRR and HIRS. The "VHR" in AVHRR stands for "Very High Resolution" and it was 1km! And the H in HIRS stands for High-resolution and it was > 1km, as much as 10km (!!). So calling it "Moderate" seems like a corrective message to the community.

Why would you need more? Many of the MODIS products are 1000m X 1000m, which is too coarse for many "field-scale" applications, where you want to get down to the health of individual fields of crops, or mixed suburban/rural areas, or biomes where vegetation types are mixed at local scales.

For instance, transpiration from broad-leafed trees is very different from grasses, and "mixed pixels" of these two types can confuse models. Or scattered parking lots at the fringe of suburban areas impinging on vegetation.


It's moderate, or even "low" according to Wikipedia. https://en.wikipedia.org/wiki/Moderate_Resolution_Imaging_Sp... But it scans the whole earth every day or two.


I would guess that the moderate relates to the wavelengths that the spectrometer measures, and not image resolution.


MODIS is trying to be MODEST.


The dirty secret is that plant growth is most optimal around 1200 - 1500 ppm CO2. Likely because plants evolved in in epochs of much higher level. If levels were to drop below 120 ppm, I believe we would see mass plant die off. Pre-industrial levels were already around 180 to 200 ppm I believe (All these numbers are off the top of my head). So even if we can stabilize around 400 ppm now with renewable, AND start to sequester back to pre-industrial levels, we would need to also make sure we can turn that sequestration OFF at some point. It bugs me to see future nascent industrial applications that want to pull CO2 out of the air for products. We could very well get into a situation in the future where we are begging industry to STOP pulling CO2 out of the atmosphere for fear or crop failure, instead of pumping it out. It may take 1000 years, but levels will come down a bit naturally if we can stabilize. That stability will only come from technological advances like electric cars, planes, trucks and lab grown meats. No amount tax or cap and trade is going to make any sense unless India and China are also on-board.


We could always go back to burning wood to increase the CO2, if your scenario were to happen.


On a related note, here is a discussion about how many trees it would take to solve climate change: https://earthscience.stackexchange.com/questions/2639/how-ma...


Here's an up-to-date study and discussion of that question: https://news.ycombinator.com/item?id=19248716

The number of trees needed (1.2T) is pretty close to the estimation of the accepted answer in your link (1.5T). The difference is, the up-to-date study has found that there is enough space for the trees. Now we just need to plant them :)


>The researchers point out that the gain in greenness seen around the world, which is dominated by India and China, does not offset the damage from loss of natural vegetation in tropical regions, such as Brazil and Indonesia.

So is it a net gain or not?


It is, although replacing forests with pastures should not be indicative of CO2 sequestration, but the opposite.

In Brazil there's a biome called cerrado[0], characterized by low trees and shrubs, from the sky might seem brown but there's a lot of biodiversity and flora. Replacing it with soy fields should not be a net gain in my book.

0 - https://en.wikipedia.org/wiki/Cerrado


Would it be possible to turn a desert region into a rain forest? For example if Nevada decided to plant trees in the dessert is it possible with enough irrigation or would all the trees just die?


I suspect it's about recreating the ecosystems rather than just planting trees and irrigating i.e. multi-decade process

Geoff Lawton's permaculture work on 'Greening the Desert" is well worth a watch e.g. https://www.youtube.com/watch?v=yI9wMtTvWps

(plenty more videos around if you search)


https://www.youtube.com/watch?v=vpTHi7O66pI I watched this talk a while back, TL;DW Yes, you can.


it was a little mystifying that he answered the question about how they bootstrap the process with "we've never had to supplement feed" alongside "no grass in sight for 100 miles"... does anyone have a longer answer?


Those are quite impressive results


Even if you did that, unless you bury the trees after they grow, they'll just rot and release the co2 back in the atmosphere. Trees aren't supposed to be a buffer for increasing co2 levels. They just use co2 as a reusable resource.


Normally if you get a forest going, it would replenish itself, not just grow old and then vanish - thus being a buffer.


I agree, but a tiny one. You can't pump half the oil out of the earth's crust that formed there after millions of years, burn it into the atmosphere, and recover the co2 by growing a forest on the surface, no matter how big it is.


Salt would be a problem in the low-lying areas, and irrigation can increase salinisation.

https://en.m.wikipedia.org/wiki/Dry_lake

https://en.m.wikipedia.org/wiki/Soil_salinity


Some problems: 1.Forest fires within a dry climate(vs humid jungle).

2.If the water table is too deep, trees will need artificial irrigation, forever.

3.It seems easy to create a single-point of failure : monoculture of "best-performing" tree species which would succumb easily to specialized insects or fungus.


1. Forest fires need base fuel load to propagate. This is the organic matter at ground level, formed from the dead stuff that trees drop (leaves, branches, whole dead trees, etc). In other words, forest fires only happen in mature forests that are left alone to accumulate base fuel load.

2. Tree raise the water table under them, by providing shade (so water on the ground doesn't evaporate as quickly and gets a chance to soak into the ground). They also prevent water tables from surfacing (by drawing the water up from their root systems). In other words, a mature forest will manage the water table, rather than being managed by the water table. You get water table problems if you cut down too many trees. Growing more will solve that.

3. this is true. There are lots of ways around it, though, if your goal is to green the desert rather than creating lots of cheap timber quickly.


In UAE it works well. You need artificial irrigation, but only one or two generations of trees. Everywhere around UAE there are many new plants randomly popped from the sand only after about 10-15 years of artificial forests.


Are there any useful nutrients in the desert floor? Or would it also require fertilization?


> enough irrigation

Pretty big if.


Don't let anyone twist this news into an excuse for climate-apathy. First, making the Earth greener will require human cooperation, specifically towards the goal of reversing human-created changes as much as possible.

And second, the Earth might get greener as a result of climate change, and that those changes might not necessarily be what is best for Humanity.


Nothing brings me more joy than seeing a greener Earth, especially the greener part is taking place in China!


It was actually identified that most of the green areas are now farming land/cropland and NOT forests.


I don't see how this addresses the issue of deforestation in places like the Amazon.

The effect that this "practice" has had on the environment is irreversible at this point.

But to each his own. Any positive news regarding the environment are always welcome.


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80% of my country's (Brazil) energy generation is done through renewable means. This isn't even close to true for most first world countries, and certainly not the US. Maybe before worrying about countries you know nothing about (as well as carelessly calling our elected officials fascists) you should start looking at your own, wherever you're from.

https://en.wikipedia.org/wiki/List_of_countries_by_electrici...


80% of the electricity generation, not energy.


Indeed. Americans are quick to point their fat fingers at others while they drive their humongous vehicles to the drive-through.


I've noticed a trend where Americans outright call Bolsonaro a fascist, even serious economists appearing on podcasts. I suspect they are compensating for not being "allowed" to call their own president what they really want to.


>Americans

>I suspect they are compensating for not being "allowed" to call their own president what they really want to.

If there's one country where you're free to say whatever you want about the president, it's the USA.


> whatever you want

(asterisk) https://www.youtube.com/watch?v=D5bEwcJ8eCI

But the person you're replying to was clearly using quotes to put emphasis on the fact that they are in fact allowed to do that, but there are social/political consequences for it. (And they're right. Look no farther than HN: During the election and much after it, there was a clear movement to "treat both sides equally".)


Let’s be accurate: left-wing Americans call him a fascist. But to be fair to Bolsonaro, the other guy was worse.


I don’t think being a fascist has anything to do with deforestation. There’s a history of fascists wanting to preserve the “motherland”. Even views such as ecofascism as portrayed in Linkola’s Can Life Prevail?

I only care about ecologically minded governments and I don’t care about left or right. It’s the only important issue at this point.


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I wish that the Democrats would concede on abortion, guns, religion, racism and everything else - as long as the one thing they do get is a majority that will start dealing with our climate emergency

I don't think you have a handle on the right's agenda in the United States, nor how the left can create a majority. Conceding the issues that you describe here would take the United States further away from dealing with our climate emergency.


That’s the one thing that will actually cost corporations money, so it’s the last thing they will address. The other things aren’t really issues to the corporate politicians, they’re just talking points.


This is about the worst kind of end justifying the means mentality. This type of thinking should be avoided as much as possible.


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These kinds of comments damage the quality of discourse on HN.


Besides which, it's the ongoing fake brouhaha about "Russian collusion" that has already guaranteed Trump's reelection. Regular people don't believe that BS anymore, and they will remember it, no matter how savagely the Ds attempt to discredit the theoretically-soon-to-be-released Mueller report. If Ds had just moved on to important matters, Trump would have little hope, but as it is he will appear to be the adult in Washington.

To be clear: Trump is a corrupt person so there probably is lots of corruption to report. We all hung our hats on a particular flavor of corruption that involved him working with the Kremlin to get elected, which did not happen.


Is the report out already? I must have missed it.


I basically agree. I've always felt that Trump's most strident critics reached too hard for sensationalism, missing many opportunities to make valid criticisms while preserving their credibility.


>I only care about ecology minded governments and I don’t care about left or right. It’s the only important issue at this point.

This is a rather strong statement given that it comes right after a recognition that fascist governments have historically had some ecologically friendly ideals. Are we talking about accepting literal genocide? Like, if we don't take care of the environment then everybody dies, so a fascist dictator who systematically wipes out an ethnic minority but also drastically cuts carbon emissions and restores a rainforest is a net-win? I'm not trying to put words in your mouth, I'm genuinely curious if that's what you're talking about, or if I'm parsing unintended meaning in your comment. I could see it either way.


IF we are taking about the end of the human race, which is in fact a possibility if we continue with the current trends, then anything that could curb human appetites and populations is free game IMO. People don’t realize what’s at stake. Interpret that how you like.


Okay, so we're talking about genocide not as an acceptable loss in exchange for sound environmental policy but rather as an environmental policy in its own right through its active reduction in the number of living humans. Glad we cleared that up. What do you think the chances of us having a lively planet in 200 years are without your proposed mass killings? What is your ideal target number for how many humans would be left after a purge, and how does it affect your guesstimates for how likely our planet is to survive? If you're willing to suggest mass killings, I suspect that you've given those sorts of questions some thought. It would be hard to justify mass killings if you didn't have some strong opinions about how likely ecological armageddon is in both scenarios.

Edit: typo.


It seems like the worst kind of optimism to think that your cozy way of life can be preserved while also saving the planet. Electric cars and trendy vegan diets aren't good enough. You should give the arguments of deep ecologists like Linkola serious consideration, not dismiss them out of hand as unsavory.

Another note: Anti-Malthusians (including a few prominent HN posters who might show up in this thread when they wake up this morning), are always quick to gleefully point out that we haven't run out of food in no small part thanks to the development of synthetic fertilizer. What they loath to mention is the ecological impact of massive population growth, and the fact that humanity has already surpassed ecosystem's carrying capacity when you consider ecological impact.


technically, we have no stand to blame them on developing their economy...


Here's a fun thought: they could hold the rainforest hostage. Hey world that relies on our land to absorb carbon, we're gonna start deforesting and developing x acres per year unless you pay us y dollars not to. Nice biosphere you've got here, it'd be a shame if somebody threw a brick through the equilibrium...


Equador tried that [1]. The world didn't care.

[1] https://www.npr.org/sections/money/2013/09/02/216878935/ecua...


The money has never indicated it cares about global warming or sea level rise. No rich people are looking to liquidate their beachfront New York, Florida, or California property, and they're certainly not buying up Alaskan beaches speculating on the next Greenland farming bonanza. Startup idea: global warming REIT.


Who is them? I didn't know countries had divinely invoked certificates for owning the planet. It is all in your head buddy.


It is generally recognized that people who inhabit a particular region rightfully determine what happens in that region. That may mean that multinational corporations have more difficulty subsuming and consuming particular local economies as quickly as you might prefer, but that's just tough.


LPG/LNG have made their impact on cooking fuel sources in these two massively populated countries; this was a positive consequence?


I need help learning this stuff, i am new to this, and i want to help the community


I like how America didn't spend billions of dollars for them to do this. Kudos.


Or maybe just the resolution of the satellite images have just improved resulting in what appears to be a more greener earth.




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