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Mars may be emerging from an ice age, according to a new study (theverge.com)
122 points by jonbaer on May 27, 2016 | hide | past | favorite | 67 comments



Following this story for the last couple days, it's interesting to see that based on the same research, the headlines have become more and more certain of the results. What started as "Mars may be emerging from an ice age..." has quickly morphed into "Mars is emerging from an ice age..."



It's classic herding behavior; that being earlier adopters are more willing to take risks in their view of reality, but also pragmatic in their observations.

The mainstream takes less risk and constructs a reality based on absolutes.

Laggers believe their reality is the only true one; when confronted with a reality that does not match their own, they ignore it until it's no longer an option to do so.


That's interesting, and of course ice ages have probably helped Mars retain more of its water than it otherwise would have, since it doesn't have a strong and protective magnetosphere.


How amazing would it be if this triggered runaway global warming and Mars terraformed itself?

But even just a few degrees warmer might still be very interesting.


Without an atmosphere, would be hard to start a greenhouse effect on Mars. [1] Carbon dioxide, as well as methane, have been long detected, but you need large amounts of these gases.

[1] https://en.wikipedia.org/wiki/Mars#Atmosphere


I counter your link with this one:

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

There is presently enough carbon dioxide (CO2) as dry ice in the Martian south pole and absorbed by regolith (soil) on Mars that, if sublimated to gas by a climate warming of only a few degrees, would increase the atmospheric pressure to 30 kilopascals (0.30 atm),[26][not in citation given] comparable to the altitude of the peak of Mount Everest, where the atmospheric pressure is 33.7 kilopascals (0.333 atm). Although this would not be breathable by humans, it is above the Armstrong limit and would eliminate the present need for pressure suits


For how long? Won't the lack of a global magnetosphere on Mars make that a relatively short term "fix"?


For hundreds of millions of years if not billions. It takes a long time for the solar wind to push that amount of gas away from a place with gravity even in the absence of a magnetic field.


The rate a lack of magnetosphere causes your atmosphere to be stripped away is in the order of hundreds of millions years.


This is a chicken-egg problem: in order to heat Mars you need greenhouse gases in atmosphere; you can only get that gases in atmosphere by heating Mars.

The only situation were this wouldn't be an issue is if the Sun is increasing the activity/power output so that the energy inputs the Mars system from outside. Then Mars would heat and the process would start.

But without active vulcanism or tectonics or mangnetic core, Mars would not heat by itself.

Terraforming by droping bacteria on Mars that would start releasing the gases faster is an option, but only when we are 100% there is absolutely no life on Mars as of now. We don't have yet this proof and therefore this solution is portponed until then.


But this whole thread is about Mars becoming warmer on its own because it's exiting an ice age. That's the chicken to your egg right there.


Would the energy from the impact of a big asteroid be enough to heat up Mars to that point? If so, maybe we could try to change the course of such asteroid to make that happen :)


It's my understanding that Mars doesn't have a magnetosphere to speak of, which significantly contributes to the lack of atmosphere on the planet.

How would a would-be terraformer address that?


I'd like to see Venus go towards an Ice Age, which might bring down the surface temperatures from average 462 degrees Celsius to Earth norms, and then maybe the place could be relatively habitable, albeit still with 96% CO2 and clouds of sulphuric acid to deal with.


The atmosphere of Venus, for what it is worth, is one of the most Earth-like places in the solar system. Breathable air is a lifting gas in the thick Venerian atmosphere, making floating habitats viable. Furthermore, at the altitude where the pressure is 1 atm and a habitat would stabilize (around 50km), ambient temperature is also in the range for liquid water. And even at this height, there would still be enough atmosphere left to provide protection from cosmic radiation.

https://en.wikipedia.org/wiki/Colonization_of_Venus#Aerostat...


The atmosphere also contains high levels of sulfuric acid which would be a bit of a concern. It's definitely a route worth exploring. It just comes with it's own set of crazy concerns.


Iirc, most of the H2SO4 haze falls below the habitable altitude, however there are clouds of it at that height. Biggest challenge would be the lack of water. You'd have to extract hydrogen from the acid to make water.


Yup. Problem with Venus is just that the ground is too far down.


The insane air-pressure ruins it. Basically, the solution to terraforming Venus is to convert the CO2 into water. The problem is that this requires hydrogen that's not readily available to do it. A lot of it.

How much?

At 1 Earth atmosphere, imagine a balloon filled with Hydrogen the size of the planet Mars. It would take two of those.

But then you could scrape enough CO2 out of the atmosphere to make oceans and Earth pressure.


A few years ago I read a paper that suggested freezing the CO2 out of the atmosphere, covering it with a layer of thermally-insulating material, and then putting oceans of liquid water on top of it to keep it sequestered. [0]

[0] - http://www.orionsarm.com/fm_store/TerraformingVenusQuickly.p...


Is that a good long-term solution? Can the CO2 just be left there forever?


The long term solution (per the paper) is to harvest the CO2. The paper states the CO2 will melt over time, but not as quickly as it can be harvested, and that water may even be poured in to melt it faster.


But who on Earth is so fond of CO2? right, plants via photosyntesis.

So why not sending green algae on Venus to harvest that CO2? When the temp drops, send something else, like trees.

Quite SF, but would worth a calculation.


If you want plants to do it, you need water, and there isn't any. The solar wind blew it all away.

Not just because "plants need water", because the chemistry is CO2 + H20 => O2 + carbohydrate


Indeed, you are right. Interesing link on this subject [1], it explains a bit more in detail the greenhouse runway process.

[1] http://www.vanderbilt.edu/AnS/physics/astrocourses/AST101/re...


Plants can't photosynthesize without water. No hydrogen, no water, no photosynthesis to take CO2 out of the atmosphere.


I would have thought you'd do it by making limestone. You just need lots of calcium for that.


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Not really, no... The factors that cause large scale climate changes on planets relate to how the orbit of the planet changes over time, in periodic ways. Mars and Earth, being different planets, have a different "schedule" for warming/cooling.

Earth is actually "supposed" to be heading into a cooler period, but it's clear that human influence has dramatically changed that timeline.

Here's a great overview of some of the factors involved:

https://www.youtube.com/watch?v=ztninkgZ0ws


The planet might still be going into a cooler period, while what we see right now is just a temporary warming that will trigger that cooling. ( i.e warming causes glaciers to melt, which in turns changes/stops jet streams, which lowers the temperature all over the globe )


The data collected points unanimously to this not having happened in the previous ice ages.


Melting glaciers results in a lower albedo, which results in more warming.


It's not like they orbit the same star or anything.


The star is not the primary driver of periodic climate variation.

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


Except for Mar's climate change happens on the course of hundreds of thousands of years, and yet here on Earth the biggest climate change has happened in the past 100-200 years, and just so happens to perfectly coincide with humans discovering industry etc.

I assume if humans didn't exist Earth would still have climate change, see also: ice ages etc.. but that kind of thing doesn't happen over the course of 100 years, not without some external influence anyway (such as an asteroid impact etc)


Well, doesn't Earth go through warm and cold periods just as Mars does? In fact not so long ago we had a mini ice age, and that was not caused by human activities. We are destroying our environment, and I'm not climate change denier, but I do think this is little more complex issue than we're being told.


Not only that, but not so long ago (in geological terms) the Midwestern United States was covered in several miles of ice.


We are technically still in an ice age.

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


In fact the Little Ice Age was probably caused in part by human activity, or rather the lack of human activity due to reduced populations in Europe and especially in the Americas.


>> on Earth the biggest climate change has happened in the past 100-200 years

Oh, really?

https://en.wikipedia.org/wiki/Geologic_temperature_record#/m...


Look at the scales on that chart. It starts at millions of years before present, then drops to thousands of years before present, and then our last 200 years is basically a vertical line at the very end of the graph.


Yes, really "NumberCruncher". Which period on that chart do you think shows a more rapid change?


There are several periods in the Pleistocene that see dramatic rises. The graph itself, with it's logarithmic scale on the X axis, does not make it at all clear. Also, the methods used to determine the average temperature are necessarily going to be different for the Pleistocene than now. That makes it inherently hard to make useful comparisons.


What's your point? If you're posting a graph as confusing as this one (4 completely different x scales) at least tell us your interpretation.


I didn't find it confusing.


This is a silly comment.


>unlike Earth, climate change on Mars is affected primarily by how "tilted" the planet is.

>Mars’ axis is currently tilted 25 degrees, but it wobbles between from 10 to 40 degrees.

So a different effect.


Well, our planet also has axial precession, so the same effect could be causing the warming on our planet right?


Yes, it absolutely does cause warming at times. In fact, prior to human effects, it was the driving cause of climate variation. These periodic variations driven by orbital changes are called Milankovitch cycles[1].

Unfortunately for your theory, Earth's axial tilt is decreasing at the moment, and therefore we should be in the 'cooling' phase of the cycle.

[1]: https://en.wikipedia.org/wiki/Milankovitch_cycles


Nope, that effect is currently making Earth colder, but is being overwhelmed by greenhouse effects resulting in net higher temperatures.


> it wobbles

But it doesn't fall down.


No, please read the article. It says the main driver of climate change on Mars is the wobbliness of its axis, which is not a factor on Earth.


It absolutely is a factor on Earth. Right now the axial tilt of the Earth is decreasing, which should be resulting in a cooling effect.


Earth also has axial precession, so "wobbliness" could be a factor on Earth.


Indeed it is. James Hansen discussed it at length in his book Storms of My Grandchildren.

You may have heard that in the geological record, warming often begins before CO2 rises. The wobbling is the reason for that. It causes a little warming, the warming causes some CO2 to be released, the CO2 causes more warming, and then you've got a positive feedback cycle that warms up the planet by several degrees.

That's why scientists are so worried that the CO2 we're emitting will cause a major problem.


Sure, all the things you're suggesting "could" be factors. Are you saying you think climatologists have not thought of any of these ideas? Or they've investigated them and made some massive mistake? They're all lying?


>Are you saying you think climatologists have not thought of any of these ideas?

Yes.

> Or they've investigated them and made some massive mistake?

Yes.

>They're all lying?

Yes.

Whatever it takes to bring in those grants money!


> Isn't it plausible that the same force that is causing warming on Mars is the main cause of our problems on Earth?

Your hypothesis is about as likely as the one where human activity on Earth is causing warming on Mars. No. Climate change is not really in dispute, and neither are its origins in human activity.


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Gold


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It's really interesting how you get to this position.

There are very many scientists who think that global warming is happening, and is caused by humans.

There are a small number of industry groups and politicians, mostly on the right, who think global warming isn't happening (or if it is happening that it isn't caused by humans) - these groups use the same techniques used by big tobacco to spread uncertainty and doubt about the overwhelming scientific consensus.

Yet somehow global warming is a "leftist"[1] conspiracy, a religious belief.

[1] That word is a great signal, btw.


I think deciplex is referring to scientists. There are of course a lot of people who make claims that arent based in fact in the face of mountains of evidence from the scientific community.


..and mountains of political agenda from individuals who "claim" to be objective in their pursuit of the truth.


You've been using HN exclusively to post inflammatory ideological comments. Lashing out at perceived enemies is not what this site is for. If you can't or won't stop doing it, we're going to ban your account. I don't want to do that, which is why I've asked you so many times to stop, but at this point you're doing little but abuse this site.


> Isn't it plausible that the same force that is causing warming on Mars is the main cause of our problems on Earth?

If only thousands of climate scientists had spent decades doing research on such things and come to an overwhelming scientific consensus! That'd be so nice.


consensus != truth


The scientific method is thus far the best way we've demonstrated to finding out the truth.


`emerging` from something that `ended 400,000 years ago`. right.




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