Global Warming Mostly Confirmed - On Mars

dinotrac writes "A just-completed 23 month study, carried out over the course of a Martian year, found that the Martian polar ice caps are rapidly eroding, sending large amounts of the greenhouse gas carbon dioxide into the Martian atmosphere. If this pattern continues over time, Mars could go from a planet whose winters are cold enough for dry-ice snow to having a shirt sleeve atmosphere. Humans would still have to provide for oxygen, but plants could go naked. I wonder if this means tougher emission controls on the next Martian rover?"

Re:global warming

[Icy]

The Ozone layer and global warming are NOT related. So many people see these as the same thing, and they are not. The hole in the ozone layer simply allows for more UVB to reach the ground. The UVB has been linked to skin cancer, cataracts, damage to materials like plastics, and harm to certain crops and marine organisms and that is it. The green house effect is where a blanket of gases is formed around the earth that traps radiation and is natural and we need it. It stabalizes our temperature. But too much of this effect is what is believed to cause global warming.

Re:If plants can go naked so can we (eventually).

[Kotetsu]

You might be getting it from a movie, but it's actually correct. Unfortunately, Mars' atmosphere would be considered a usable vacuum here for many purposes. Even more unfortunately, it's probably not correctable over the long term. Mars lacks a significant magnetic field. [spaceweather.com] This results in erosion of the atmosphere by the solar wind. Unless a way is found to create a large enough magnetic field to protect an artificial atmosphere, it will bleed off into space as the original one did. This also leaves inhabitants much more vulnerable to radiation from solar flares and similar events.

naked plants

[oyenstikker]

Plants, like us, need oxygen for their respiration. They photosynthise to create a lot of what they need, and kick out more O2 to the atmosphere than they will use, but there still needs to be a high enough O2 concentration in the atmosphere for them to take some of it back in.

Influence of solar activity

[p4k]

This would seem to support the theory that variations in solar activity are very significant in determining climate. It is known that the output of the sun is slightly higher during periods of high solar activity [nasa.gov]. We are just about at the peak of a solar cycle at the present, and the last few cycles have been strong, and it would appear that this is affecting the climate on both planets.

This graph [microtech.com.au] from this report [microtech.com.au] shows a striking correlation between the length of solar cycles and mean temperature over the last hundred years (interesting that the length of the cycle should give the best correlation - the authors suggest the shorter solar cycles correspond to higher solar output).

Also, there is considerable historical evidence that the current change in climate is really pretty small beer compared to what has happened in the past:

"The Norwegian farmer Folke Vilgerdson made the first attempt to settle in Iceland in about 865 AD... He lost his cattle in a severe winter and disappointed went back to Norway after having seen a fjord filled up by sea ice. Therefore he called the country Iceland. Only a few years later, in 874, Ingolf Arnason succeeded. He was followed by many others, and settlement was completed in 930 AD... In 982, Erik the Red discovered new land West of Iceland. He called it Greenland; according to the Greenlander Saga this was only to persuade people to follow him... But the O(18) curve suggests that the name described a reality... So the drastic climatic change [warming] late in the ninth century may be part of the reason why Iceland and Greenland did not get the opposite names." (Dansgaard: Palaeo-Climatic Studies on Ice Cores, in Oeschger, Messerli and Svilar, 1980).

Here [skywebsite.com] is another account, also suggesting that Greenland had a suprisingly comfortable climate at the time.

Most of the atmosphere went down, not up.

[Spamalamadingdong]

Photodissociation of water may have released a lot of Martian hydrogen to leak away (the very high proportion of deuterium in Martian water compared to Earth's strongly argues for this), but the oxygen and whatnot are too heavy for much to escape that way. The only place for them to have gone is down.

This means that the oxygen, nitrogen and carbon are probably in the soil. This would explain why Mars is so red (all that oxidized iron) and why the atmosphere is so rarefied (most of the gases are tied up as permafrost, adsorbed gas or chemical compounds like nitrates). It also means that the right kind of change can release them and make them into a thick atmosphere again.

Bob Zubrin of the Mars Society has written that we could start what would probably be a substantial greenhouse effect on Mars with only a few million tons of greenhouse gases (such as sulfur hexafluoride and methane) per year. This is the output of one large-scale industrial plant. Once you start heating the soil the adsorbed gases come out and the permafrost melts, leading to more warming and more gas release. Once you've got 200 millibars of atmosphere you can walk around outside with nothing fancier than a heavy parka and an oxygen mask. That's not bad for a planet that's currently an iceball with 7 millibars of fire-extinguisher contents for "air".

Re:You think Kyoto would have been enough?

[boltar]

Once the developing countries had developed to
a certain point their CO2 output would have been
frozen. The whole point of Kyoto was to provide
a paltform for the eventual reduction of CO2
emmisions. If you think its all bull you might
be interested to know that if it wasn't for the
current of CO2 in our atmosphere the AVERAGE
temperature of the earth would drop to appox -30C.
What do you think doubling that amount will do?
Sure it won't happen immediately because of the
buffering effects of the oceans but once it does
and we don't do anything about it we're in deep
shit as it'll cause melting of the siberian permafrost
and the oceanic methyl hydrates and god help us
when that happens.

Re:global warming

[Anonymous Coward]

You might enjoy these pages about global warming and how the corrlation between tempature and solar events is rather high.

The Wall Street Journal [junkscience.com]

Penn State University [psu.edu]

Re:Quick, call GreenPeace!

[tchuladdiass]

Actually, the theory goes (according to a show on Discovery channel): 1) Global warming will cause the polar ice caps to start to melt.

2) This will cause the oceans to become less salty near the poles.

3) Since the heavy salt concentration at the poles drives ocean current, less salt means the currents will reverse.

4) Once it reverses, the planet will become signifficantly colder, since the ocean currents are responsible for distributing warm air. Also, once the currents reverse, it will take thousands of years for them to go back the other way.

Apparently, it will only take about a hundred years or so of increased temps to cause this to happen, and start the new ice age. (Note: I'm not sure if I believe this or not, but it is interesting nonetheless).

Cool Animations of the Melting Ice Caps

[EccentricAnomaly]

Here are some "cool" animations [msss.com] where you can see the ice caps melting. Also, here's a JPL press release [nasa.gov] which is a little more level headed than the news coverage.