If you live in the Arctic, don't try this at home - Methane from melting permafrost, a powerful greenhouse gas, gushes out through a hole in an Arctic lake.
Last week, as snow and ice appeared to shut London completely (apart from a few hardy Greenpeace souls who stumbled to work in near-blizzard conditions,) it was perhaps inevitable that we got a few emails about the weather. This post goes out to Debbie, who emailed me to ask "why it so cold when you predicted a rise in global temperatures are you wrong?" Well, in the spirit of answering that question, allow me to present the first in an occasional run-down of some current hot topics (sorry) in climate science.
1. The Antarctic is definitely melting
The planet is getting warmer - had you noticed? While it's been pretty clear that the Arctic area has been warming up for a while, what's been going on in the Antarctic has been less clear. (Climate science is quite complicated - a fact that certain commentators like to take advantage of in order to mislead people.) This week, however, a paper was published showing that the continent is definitely warming up, especially the West Antartic, which is more vulnerable to warming effects. RealClimate have a very geeky run through of why this is an important paper, using some quite long words. (It was also covered using words I understand fully by the Telegraph and Science Daily amongst others.) Al Gore put it a bit more succinctly.
2. California is heating up and drying out- the US is waking up to climate change
Meanwhile, in a shocking reversal of 8 years of wilful idiocy on the part of the government, somebody actually seems to 'get' it - Obama's new energy secretary stated in an interview with the LA Times that California's farms and vineyards could disappear by the end of the century because of global warming. Putting it in terms of food and booze is a good way to get people's attention - and underlies that while we hear a lot about melting ice and polar bears, for a lot of the world climate change is really going to be about not being able to get enough food and water.
3. The effects of climate change are ‘irreversible'
The big climate science paper published this week was ‘Irreversible climate change because of carbon dioxide emissions,' in which a team of scientists described how long the effects of climate change last once we've caused them. Short answer is: effectively forever. This is basically because once it's up there, carbon dioxide sticks around in the atmosphere for a really long time. Any changes in climate we cause we're stuck with. However, as Climate Progress notes and RealClimate point out, this isn't just doom and gloom:
Climate change is like a ratchet, which we wind up by
releasing CO2. Once we turn the crank, there's no easy turning back
to the natural climate. But we can still decide to stop turning the crank, and
the sooner the better.
In other words, it's what we do now that matters. I choose to interpret that as "Stopping new coal fired power stations and aviation expansion right now is critical."
4. The atmosphere is like a bathtub
The climate idea which really surfaced on the blogosphere this week was that of the ‘bathtub' metaphor for climate change. Imagine that the atmosphere is a bathtub. The flow of carbon dioxide into it is the taps. Addressing the problem is all about turning the taps off - stopping things like aviation expansion and new coal fired power stations. But turning the taps off doesn't solve the entire problem - because it's actually the amount of water in the bath which warms the planet, not how much the taps are on. (This is a good argument for turning the taps off as quickly as possible.)
The bathtub metaphor is important, you may not understand it, (I didn't) but Andrew Revkin at the New York Times wants to explain it to you (with videos).
5. And finally... The Arctic sea ice is (still) melting
And finally, let us turn to the Arctic sea ice. I should issue a disclaimer: I am an Arctic Ice geek. The Arctic ice cap behaves like a giant, icy yo-yo. Every summer it melts and gets smaller, every winter it refreezes and gets bigger. Aficionados of the Arctic may be aware that in Summer 2007 it melted away quite dramatically, to the smallest it's been since records began - you might also know that 2008 probably saw the lowest volume of sea ice in the Arctic since records began. Both events are important. The less volume the ice cap has, the thinner the ice is - meaning it breaks up and melts faster in summer. And the smaller the sea ice cap gets, the less sunlight it reflects, and the faster the planet absorbs the sun's heat energy. As the ice cap goes, the planet heats up faster.
How the Arctic sea-ice has changed from 1979 to 2007 - the white is old ice, the blues are newer ice. You can see that it's getting smaller and thinner...
Mid-September is when the ice cap is at its lowest level, and it's quite possible that September 2009 will see a new low in sea-ice levels. We'll be paying close attention to the state of the sea ice over the coming year, and keeping you posted. Or for the most up-to-date briefings on the state of the ice check out the National Snow and Ice Data Center.
