Let me preface this by saying that I believe climate change and decarbonization to be one of the critical challenges of our time. That said…
This article’s title and its content are completely at odds. Here’s a critical passage:
> As the ice sheet melts, its surface will be at ever-lower elevations, exposed to warmer air temperatures. Warmer air temperatures accelerate melt, making it drop and warm further. Global air temperatures have to remain elevated for hundreds of years or even longer for this feedback loop to become effective; a quick blip of 2 degrees Celsius (3.6 degrees Fahrenheit) wouldn’t trigger it, Höning said. But once the ice crosses the threshold, it would inevitably continue to melt. Even if atmospheric carbon dioxide were reduced to pre-industrial levels, it wouldn’t be enough to allow the ice sheet to regrow substantially.
> “We cannot continue carbon emissions at the same rate for much longer without risking crossing the tipping points,” Höning said. “Most of the ice sheet melting won’t occur in the next decade, but it won’t be too long before we will not be able to work against it anymore.”
So…we potentially have hundreds of years to bring temperatures back down before the “tipping point” triggers? Forgive me for not being super alarmed.
100 years ago we’d just barely started dumping carbon into the atmosphere. That is a long time.
EDIT: to be clear, yes of course it not enough to stop dumping carbon into the atmosphere in the next hundred years, but it does give us (potentially) decades to figure out large-scale carbon capture and sequestration even if we exceed the thresholds described here (1000 gigatons).
No, the story is that we begin the melting by raising the earth's temperature a little. You'd think that if we reduced our carbon emissions, the ice would stop melting.
> But once the ice crosses the threshold, it would inevitably continue to melt
Bear in mind that the atmosphere retains carbon dioxide for ~50 years, that other melt events are dumping methane into the atmosphere from permafrost. It's not just one factor heating the planet.
>You'd think that if we reduced our carbon emissions, the ice would stop melting.
People think of climate change like a river. You reduce emissions, you reduce the size of the emissions, you reduce the size of the problem.
But it's more like a bathtub. Emissions are the water filling the tub, but the real problem is the water level already in the tub. If you reduce emissions, you reduce the size of the flow into the tub. But....water is still flowing in and the water is still rising.
If we had zero emissions it would take earth systems much much longer than 50 years to bring things back down to where they were.
I don’t understand the bathtub analogy, but I will say it should be a goal of humanity to control the climate of the entire earth. The alternative is we don’t and are forever at the whim of what Earth and the solar system decides to throw at us.
I’ve found this argument to be appealing to people on both sides of the climate change debate.
I agree tbh, a modern focus is one of conservation; what better way to guarantee the ongoing proliferation of various species other than being able to control the environment they live in.
Controlling the climate (and by that of course we mean very carefully holding it at what it should be) benefits all life on the planet.
Good thing plants eat carbon dioxide then, so we don't need to wait for it to break down by itself. The more CO2 in the atmosphere, the more plants grow and convert it to oxygen.
Plants only store the CO2 until they decompose a relatively short time later. The only way to end up with a net decrease in CO2 this way is to bury the plants deep. Of course that is the process that initially created coal.
The amplitude of the world's natural CO2 cycle is on par with about 1.5 years of anthropogenic emission. Which is certainly impressive, but it's cylic and fairly steady. Plants are not growing fast enough to support the fantasy you describe.
Said another way, within two full human lifetimes the planets climate could further be irreversibly changed locking in 23 feet of sea level rise from Greenland alone.
Though, generally for emissions we are talking about a first order derivative. Just because you've slowed down from 100 to 50 does not mean you won't still run out of roadway.
So, if we are a hair away from that tippingpoint, and magically go to zero emissions, we'll still hit the tipping point. Hence, it's not two lifetimes, but that is the total runway left so far for this.
You can also consider the other extreme where CO2 is dumped into the atmosphere that everything shortens up. Another analogy, boil some water, put it off the burner, drop a small amount if ice in the water. The water won't cool off fast enough for the ice to not melt. It may take 10 minutes for that to happen, but the point of no return was when the water started at a boil.
You and the models of climate 200 hundred years hence have no actual idea of what will occur. You will be dead, however and this is certain.
It is baffling to me that it is a concern to you or frankly anyone that is not of extraordinary wealth.
Why? I tell you why: all effective measures at "reducing climate change" (very status quo) will unquestionably make life more laborious and less comfortable for the lower 98% of humanity. Our sacrifices will permit the 2% (or fewer) extravagance beyond what we've ever seen.
The permafrost will melt unleashing massive forests worth of growth, huge swaths of frozen soil will become inhabitable and fertile.
The ancestors of the Americas lived on the coast, 400 feet below today's surf. No one lamenting the old huts weve lost along the way
I think you successfully got my goat. But a few things to consider:
(1) The climate models of the 1970's were actually incredibly accurate, 50 years
later.
(2) We are pretty close to 2 degrees now (AFAIK we are at 1.6 currently and rising). The current models have us breaching 2 degrees in the next couple decades, if not already breached. (Any reason to believe our current models for the next 20 years are far less accurate than the models of the 1970's for a longer time scale?)
(3) We need warming of 2 degrees for up to two centuries to lock in the melting of Greenland's ice sheet.
(4) Once we breach 2 degrees, the timer starts. How likely do you think it would be that we would stop emissions to arrest that growth? How difficult would it be to even get back under 2 degrees (to then actually _lower_ the temperature).
Hence, unless we want to not only figure out a way to eliminate emissions, but also reverse those effects; we are best staying under 2 degrees. The time threshold for staying under 2 degrees is quickly passing, and that is not a problem for "hundreds of years from now". If you care at all then about your grandchildren having anything resembling the comforts of you; perhaps you would also be concerned about the implications of breaching 2 degrees and how important it is to stop that increase before we even consider how to reverse those effects.
Last point, considering it is the 2% [0] are the ones doing most of the emissions, then this concern over the change for a more laborious and less comfortable life for the 98% seems misplaced.
[0] It turns out it's actually the top 10~20 percent that do most of the emissions, with more from the smaller fraction. The point is all the same though.
In short - the emphasis from this statement is extremely misleading: "hundreds of years or even longer for this feedback loop to become effective."
The feedback loop will take time to trigger, but the conditions for that feedback loop to be triggered can be locked in before that time. As proof, if we emit a near infinite amount of C02 emissions to produce a run-away hot-house earth, those conditions will be locked in very quickly. In other words, if temperatures rise enough, there won't be enough time (even in a couple hundred years) for them to fall back quickly enough. That's just logic, math & thermodynamics.
> You and the models of climate 200 hundred years hence have no actual idea of what will occur
This seems like an "attack the messenger" argument. If there is enough global heating to melt the ice sheets over Greenland - the climate would be different. 1000 years ago, the climate of the Earth was not melting the ice sheets of Greenland. Now that they are on track to melt, that is different.
I only said the climate would be changed. Beyond this, the article is very well presenting a model of what would happen to Greenland's ice sheets over centuries.
Otherwise, in my comment, I'm paraphrasing the conclusions of the article and giving explanatory examples which are based on thermodynamics and what was concluded in the article. It's not my opinion (and so making this personal is irrelevant). Otherwise you're free to contradict the validity of the model, you could have a very good research paper if you could nitpick how the article is flawed.
Otherwise, saying "the models have no idea" is either nihilistic or ignorant and is very reductive.
It's like saying, "I'm projecting my finances to go to zero in a year based on the current trajectory. Bah, why change anything, who knows what will happen a year from now!"
> It is baffling to me that it is a concern to you or frankly anyone that is not of extraordinary wealth.
- Why would the non wealthy be any less concerned about their great grand children than would be the wealthy?
- Is concern for future generations of humans and every other species on the plant baffling to you?
> Why? I tell you why: all effective measures at "reducing climate change" (very status quo) will unquestionably make life more laborious and less comfortable for the lower 98% of humanity. Our sacrifices will permit the 2% (or fewer) extravagance beyond what we've ever seen.
That is your opinion. To share my opinion, I find that "comfortable" way of life to not be entirely satisfactory. That way of life (industrialized capitalism, eg: Japan or the USA) leads to high rates of suicide, depression, poor environment (polluted airs, roadways, rivers) to all be very unsatisfactory (IMO). I recall how clean the air became when there were no jets and no cars on the road for as little as one week, and that was quite pleasing.
You're also assuming that the needed changes are going to require _your_ personal sacrifice. If we, as normal people, can effectively adopt mass transit, electric cars; the rest of the needed changes are from industry.
> Our sacrifices will permit the 2% (or fewer) extravagance beyond what we've ever seen.
This is provided with no evidence and is not a logical conclusion from any of your previous statements. It's already the case that a minority are causing an disproportionate amount of emissions. In some ways, how is this not already the case? If that is already the case, then the "sacrifices" are not relevant to the "extravagance" of the 2% (our sacrifices are not a necessary and sufficient condition for that extravagance, the two are independent of each other given that extravagance seems to exist today without those sacrifices)
> The permafrost will melt unleashing massive forests worth of growth, huge swaths of frozen soil will become inhabitable and fertile.
I think you meant habitable? Beyond this, this seems like a disingenuous argument since you stated earlier that no model knows what the climate will be like in 200 years - therefore how can we conclude the permafrost would melt?
Though, taking the nihilism aside, permafrost melting would be another tipping point. This article describes another tipping point that also exists.
But, the growth of forests is not a given (so, it's not necessarily the case that we can all just shift north & south). For example, there is a C02 level (around 1300ppm) that could be reached that could cause cumulus clouds to no longer form [0]. At that point, we're not getting massive forests but instead earth would be on track to be a hot-house planet (eg: Venus)
> The ancestors of the Americas lived on the coast, 400 feet below today's surf. No one lamenting the old huts weve lost along the way
No, but it is lamentable that Buffalo, Wolfs, bears have nearly disappeared along with bio-diversity and a lot of first growth forests. Looking at satellite pictures, it's quite amazing how much clear cutting has taken place; and travelling through those clear cuts is depressing. I personally lament this loss.
So, just as we can lament the destruction of environment from those 400 years ago (more 200 years ago really), people 200 years in the future will lament us ruining the environment for them. We may disagree, but I prefer to be a steward of the environment rather than wreck it for the sake of marginal "comfort".
Stopping emissions (which isn't even in the Overton window) means CO2 concentration will slowly reduce.
"Between 65% and 80% of CO2 released into the air dissolves into the ocean over a period of 20–200 years. The rest is removed by slower processes that take up to several hundreds of thousands of years, including chemical weathering and rock formation. This means that once in the atmosphere, carbon dioxide can continue to affect climate for thousands of years."
During the time of elevated CO2 levels, the temperature continues to rise.
Previous research identified global warming of between 1 degree to 3 degrees Celsius (1.8 to 5.4 degrees Fahrenheit) as the threshold beyond which the Greenland Ice Sheet will melt irreversibly.
We're already at 1.2c above pre-industrial levels. Although it will take a long period of exposure to warm air for the ice to melt, we've already been doing that for a long time. It doesn't seem reasonable to say we have hundreds of years to figure out a solution.
> It doesn't seem reasonable to say we have hundreds of years to figure out a solution.
We've also known about the global warming problem in great detail for well over 50 years at this point. Since then we haven't figured it out but made it worse -- most of our cumulative emissions have happened in just the last 50 years. Why do people still think we can figure this out in a matter of decades without having to drastically change our fossil fuel habits?
Because people haven't come to terms with the fact that humans are not Children of God nor disembodied Cartesian rational calculators, but actually a loquacious and smartish hominid, designed by selection for small group interaction. There is nothing to suggest this species is capable of planet-level cooperation towards a communally-decided end.
Add to that the fact that path-dependent history has placed that species today in a situation where it's organised into huge 17thC mutually-hostile groups ("States"), incapable of anything more than opportunistic cooperation because of their religious and anachronistic founding concept ("sovereignty"). Most people have no idea that this contingent organisation is not the natural and inevitable state of the world, so aren't open to the possibility that it dooms them to sclerotic inability to face today's challenges.
You make interesting points but I would disagree about global cooperation.
Every day we cooperate in an intricate dance with people all over the world, from different ideologies and legal systems, to operate our supply chains and information networks.
All we need is for the green option to be in everyone’s self-interest and the system will rapidly self-optimize.
We’re already getting there with green laws being globally popular, carbon taxes, and clean tech getting cheaper.
Well it's too big a discussion to litigate here, but I don't agree that market forces + self interest have in fact been successful. Most significant problems have merely been postponed, precisely because we just don't have the cooperative mechanisms available to deal with them. Many of our ecosystems (ie. the actual physical world, rather than the virtual worlds of finance and markets) are on their last legs.
I also think the very concept of 'self-interest' is incoherent (as is 'national interest'), but again that's too large a topic for an HN comment.
My argument is that market forces have done a brilliant job in marshalling far-flung and diverse interests to optimize for the sum total of our self-interests.
For instance, I'm using this device for fun and profit and it was made by actual communists on the other side of the planet.
People until recently have not thought of the ecology as being in their personal interest in a direct and concrete way, only a vague and diffused good. Tragedy of the commons and all that.
But that's changed because now being green can be cheaper (carbon tax, cheap solar panels, other tech progress) and cool.
The market deals with all long-term significant problems this way - leave it until it's urgent, then absolutely smash it. This isn't perfect but it's probably the only way to get 8 billion decision-makers to coordinate on anything.
My point isn't for perfection, but that we simply don't deal with many global problems at all, ever. They're not left 'till they're urgent - they are ignored until they overwhelm. This is a universal, physical, biological process that happens to all organisms whose unchecked growth damages the environment they have evolved to exist in. Abstractions like 'market forces', 'self interest' and 'decision-makers' have no causal force. They are like money - concepts that skate impotently over the surface of physical reality, until their bearers are borne away.
Anyway, 'arguments' (especially those of economists - the theologians of our era, whose intellectual fairy-castles will in my view come to be seen as equally empty) are irrelevant. Rationalism lost (a historical reality economists never grappled with). Empirical reality is all. Time will tell.
Kick the can down the road. Nothing to see here. Let our progeny figure out how to clean up the mess we created. We're doing the same thing with our debt, too.
I'm just going to put it out there - our progeny is going to hate our guts.
Then again, maybe afterward humanity will hold us up as an example for what not to do, how not to solve global problems. They'll be able to use history to quickly and effectively shut down the naysayers. Of course that's assuming they bother to learn anything from history...I mean we sure as hell haven't!
As a fairly new parent, I'm not thrilled about the world my daughter will inherit. I struggle with a lot of questions like whether I should raise her to be a "good" person or a "successful" person.
But, I've heard that studies show that younger generations are more concerned about the environment. Both in that they are showing an interest in the subject at younger ages and they are more likely than older generations to acknowledge it as an issue that affects them.
This suggests that our children may not only be better equipped to handle these issues than we are (assuming we continue to advance science and technology without major catastrophe in the meanwhile), but will be more interested in pursuing these problems both personally and professionally and, in the worst case, more willing to make the necessary sacrifices to see actual change.
While I certainly hope we can do more and that I can have some confidence my children will actually be better off than myself, changing the way the world thinks is a very slow and difficult thing to do. It may be the case the best we can accomplish is to hold it together the best we can while teaching our children to care about the world around them, and, when the time comes, step aside to let them solve these problems.
I'm concerned that the "concern for the environment" is mostly green washing. It's cool to be "concerned about the environment." It's far less cool to do anything about it that's consequential.
Sure, but that's kinda the point. Changing society's beliefs and especially behaviors can take generations.
Today's adults are talking about it, but not doing enough about it. But for many of them it only became a problem after decades of not really hearing or caring about it. They have decades of experience not worrying about it and not seeing any consequences of it.
Today's kids have been hearing about it for most or all their lives. They'll grow up seeing more evidence of what's happening and how it will impact them. They won't know a world that's not talking about it.
Is that a guarantee they'll do something about it? Of course not.
Well, once the CO2 is in the air and stays there, the warming will happen. Then hundreds of years later the threshold is passed and then even removing it from the air (something we can't do) won't help anymore.
Once we've emitted enough CO2 to reach 2 degrees warming, it will almost certainly happen that all the ice melts. And there's a point where that will be certain, even if we learn how to remove all CO2 we emitted from the atmosphere. Is how I read it.
The ice on this island is enough to cause about 7m of global sea level rise on its own, iirc.
Well, if that’s an accurate measure of sea level rise, then ocean salinity would drop significantly and cool the planet very rapidly, and by quite a bit. Not sure what outcome of that would be, but dramatic sudden cooling would likely devastate agriculture.
Are you thinking of this theory? Greenland Melts ==> North Atlantic Salinity Falls ==> North Atlantic Ocean Currents Disrupted ==> Local Cooling of Northern Europe
If so, sed 's/cool the planet/cool Northern Europe/' Though yes, it'd be locally pretty dire for agriculture. Maybe they could switch to farming fish in all the newly-flooded lowlands...
The snowball Earth's (both of them) were caused by excess serpentine weathering. Serpentine is one of the most common minerals in the Earth's crust — like 80% of it. The serpentine is covered in limestone (and other things) which prevents warm-saline erosion of the serpentine, directly. If you look at the tailings from the coal mines in the TVA, you could "just" ship those tailings to the Gulf coast (using the old train systems) and cause a major glacial period, quite quickly, by grinding up the tailings & dumping them in a mile wide strip from Corpus Christi to Miami.
> Serpentine is one of the most common minerals in the Earth's crust — like 80% of it.
Serpentines are common but they do not make up 80% of the crust. Feldspars are the most common minerals in the crust and they make up less than 60% of it [1].
Temperature is a function of elevation. It's saying that if you move the surface down by removing the top layer of material (ice), the temperature at the surface increases, all else being equal including the temperature at sea level.
The effect is real, and big enough to feel with the naked skin. One generally says one kelvin per 100m elevation, although the Greenland surface will be different from that rule of thumb.
> One generally says one kelvin per 100m elevation
That's not true in Europe nor Asia nor South America nor Africa, although I didn't climb mountains specifically in Greenland to be factual. Better value is cca 0.6C per 100m, or 6C per 1km (sorry, no conversion to feet/yard vs F and similar fun games for lazy sunday afternoon... seriously, with all the love, fix this shit guys, we are not living in 15th century when similar stuff was common and accepted).
It depends on many factors including humidity and local meteorology.
That part discussed about moving surface down doesn't make sense - you can lower glacier only to base rock/soil level. But at this level, where glacier starts, its already the dreaded temperature they want to avoid, so glaciers should be melting from the bottom with this logic. If they mean that once ice melts the rock temperature rises well yeah, that's a no brainer, its a different surface. Ice has surface temperature below/around 0, any rock hit with sun can easily surpass that even during winter.
I know reality is more complex out there, one of my todos is to have sleepover (no tent) on nearby Mer de Glace in Chamonix, France. Just me, gazillion stars, mountains crumbling around me and glacier cracking beneath my ass.
>But at this level, where glacier starts, its already the dreaded temperature they want to avoid, so glaciers should be melting from the bottom with this logic.
Yes, that's generally what happens to glaciers even ignoring climate change. The bottom melts, but is replaced by snow/ice that accumulated on top. Glaciers grow top down, not bottom up. But, if you lower the top so it's warmer, less ice accumulates, which can't replace all that melts, and so you get net shrinking.
I agree that this is probably what the article tries to say.
There is another possibility, though: Maybe it's saying that a large area of Greenland's ice surface is at an elevation where the glaciers are barely staying neutral. If that's what it tries to say, then having all of that area sink by 3m means that a large area goes into decline and stays in a state of decline. The surface sinking by 3m, 10m, 20m or 50m would then be much the same, just different speeds of irreversible decline.
This article’s title and its content are completely at odds. Here’s a critical passage:
> As the ice sheet melts, its surface will be at ever-lower elevations, exposed to warmer air temperatures. Warmer air temperatures accelerate melt, making it drop and warm further. Global air temperatures have to remain elevated for hundreds of years or even longer for this feedback loop to become effective; a quick blip of 2 degrees Celsius (3.6 degrees Fahrenheit) wouldn’t trigger it, Höning said. But once the ice crosses the threshold, it would inevitably continue to melt. Even if atmospheric carbon dioxide were reduced to pre-industrial levels, it wouldn’t be enough to allow the ice sheet to regrow substantially.
> “We cannot continue carbon emissions at the same rate for much longer without risking crossing the tipping points,” Höning said. “Most of the ice sheet melting won’t occur in the next decade, but it won’t be too long before we will not be able to work against it anymore.”
So…we potentially have hundreds of years to bring temperatures back down before the “tipping point” triggers? Forgive me for not being super alarmed.
100 years ago we’d just barely started dumping carbon into the atmosphere. That is a long time.
EDIT: to be clear, yes of course it not enough to stop dumping carbon into the atmosphere in the next hundred years, but it does give us (potentially) decades to figure out large-scale carbon capture and sequestration even if we exceed the thresholds described here (1000 gigatons).