Turns out that my friend’s brother is a physical chemist who has a lot of interesting things to say in response to the abrupt <a href="http://e-center.doe.gov/iips/faopor.nsf/d75c18ae2432dc898525649c005de232
/cd548f8acf0efbe28525736900689456?OpenDocument”>climate change modeling grant posting that the feds just put out.
He sent this great rundown on how things look from his point of view:
Yes, this has been going on for a while now, and it is for real. (I haven’t looked at the link yet.) There are many possible non-linear effects which are only starting to be realized. As high-latitude melting proceeds, these effects will start to be exposed in a big and mostly unpredictable way. Most are likely to accelerate climate change, with the results likely to be more pronounced at mid to high latitudes.
Lots of examples are being discovered in the geologic record of sudden global climatic events which resulted in huge swings over only a couple of years. Many of these were related to ice age melting.
Melting tends to first form big lakes which periodically overwhelm their ice dams to make terrain changing floods that flush huge amounts of fresh water into the oceans all at once.
People have been studying ice age events (like the one that took place a little to the east of where you live) to gauge these events. An interesting scenario has a major runoff event from Greenland decreasing the salinity of the North Atlantic and shutting off the thermohaline circulation system. This circulation runs warm surface water northward from the tropics; at some point near Iceland it hits less saline water, sinks, cools, and runs south again. It is a truly global heat exchanger, and a flood of fresh water at the surface will push it downward well to the south of where it now goes.
In short, it will shut down the Gulf Stream. This will likely turn Europe into one solid chunk of ice, and could lead to arctic winters all along the Eastern seaboard. The time scale for this transition once the flood happens could be as short as a year or two. The time constant for recovery could be decades to centuries because the oceanic circulation patterns are very slow. (Think how scarcity of oil overlays on this … ) There is active research now in Greenland and Antarctica on these types of effects. Increased melting has been documented in both places.
The methane clathrates are potentially a huge source of energy, if anyone can figure out how to extract them from the ocean floor and do it in time. But if things warm up too much first, they can potentially release so much methane that CO2 effects would be insignificant.
Increases in CO2 do not increase the warming as much as you might expect because there is already so much CO2 in the atmosphere that its radiation to space is optically thick, i.e. kind of saturated. Because of this trapping effect, most of the CO2 radiation to space comes from altitudes of about 40 km, near the top of the stratosphere, so increasing CO2 at the ground doesn’t affect that very much. But methane is (more) optically thin, so the atmosphere is much more sensitive to increases in its concentration. The methane clathrates have sequestered a colossal amount of methane. Again, due to the non-linear nature of melting and thawing (like spring break-up), this methane release could happen over the course of a year or two rather than gradually over decades.
I don’t think anyone knows how much longer it will take to trigger these mechanisms. I heard just this week that the rate of CO2 increase has doubled, so maybe we are nearing the end of the linear initial slope of the warming effects. My sense is that, without the oil overlay, we (i.e. the US) could probably deal with these changes and adapt (with significant political and societal changes), especially if the political leaders face it head on and get the science/ engineering and other intellectual communities focussed on it. Indeed, there is a growing (though still ignorant) public and media awareness of the related stuff, and even the Bushies have folded on it. But as far as I can tell, even the most progressive thinkers are not coupling in the energy requirements adequately, and especially they seem unaware of the implications of peak oil and the shortfalls in the alternative technologies. I simply don’t know how to raise this awareness without being perceived as a martian.
I really would much rather be working on problems like these instead of death lasers, but there is no way to get the funding where I’m at.
But right now I intend to enjoy watching the Red Sox play in the World Series …
