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.
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.
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 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.
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.
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 :)
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.
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.
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]
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.
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:
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 )
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.
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.
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.
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.
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.
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?
> 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.
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.
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.
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.