Global Warming, 2006 

Global Warming, 2006

The Democrats seem to think--or hope--that this will be one of their big issues. See Kevin Drum in the blogosphere, Bill Clinton, Al Gore.

What exactly do they propose? Is Kyoto the be-all and end-all? What about the recent findings that trees produce methane--which is at least as serious a greenhouse gas as carbon dioxide? Part of Kyoto is a scheme to credit countries with a lot of trees--which apparently can function as carbon sinks. This may not be a good strategy:

[blockquote][The new] nugget of data becomes especially significant when taken in the context of recent discoveries that indicate the effect of CO2 on global warming is being offset almost completely by the introduction of aerosols into the atmosphere via the operation of power plants, according to a report in the Financial Times.[/blockquote]

The aerosols, it turns out, reflect solar-generated heat and have a cooling effect on the planet.

This means that methane may well be the primary driver of any warming trend in overall climate, as argued by Earth Save, which notes:

That, in turn, suggests that the methane production of trees is of far more importance to global warming, at least in the short term, than any CO2 consumption benefit they may offer -- and at least on a par with the threat posed by livestock, something the government has alread been very clear about.

Thankfully for foresters -- and not so happily for climate scientists -- Dr Lowe may have articulated the ultimate fall-back position when it comes to almost every assertion about anthropomorphic contributions to climate change.

"People who prepare the emission budgets use a bottom-up technology. Someone will make a measurement in a swamp somewhere and simply extrapolate that measurement upwards to represent all the world's swamps. They'll measure emissions from a cow or a sheep and extrapolate that upwards to include all of the world's animals," he told National Geographic.

"As you can imagine, there are huge errors. The science is so inexact that you could easily fit a new source like this into the estimates."

There is no longer any serious debate about the reality of global warming. Some may still quibble about its causes, but the focus is on what nations should do to ameliorate the effects of climate change. And this is precisely what makes the new research so disturbing. For how could so basic a source of global warming have gone undetected until now?

In fact, evidence pointing to huge holes in the science of atmospheric methane has been circulating for years. In 1998, Nature carried a study showing global increases in methane were mysteriously levelling off. Now it seems that deforestation - that bête noire of the environmentalist movement - may have helped combat the rise of this greenhouse gas. While no one is suggesting chopping down the world's trees to save the planet, the new research highlights the astonishing complexity of environmental science. Measures to combat climate change that once seemed simple common sense are turning out to be anything but.

Everyone knows fossil fuel power stations are hefty producers of CO2 and need urgently to be replaced. Yet they are now also recognised as hefty producers of aerosols - tiny particles in the atmosphere that play a key role in reflecting the sun's heat back into space. The scientific consensus was that this is a minor benefit of fossil fuel burning. But last month Nature published new research showing aerosols may be twice as effective at keeping the earth cool as was thought. Suddenly, wholesale closure of power stations no longer seems such a good idea.

Even so, it surely makes sense to use renewable sources of energy whenever possible. Well, up to a point: new research suggests hydroelectric schemes can be worse than useless in reducing greenhouse gas emissions. A study by the National Institute for Research in the Amazon in the current issue of the journal Mitigation and Adaptation Strategies for Global Change shows that the vast lakes used to feed hydroelectric turbines are a rich source of rotting vegetation - and thus methane. One such scheme in Brazil is now believed to have emitted more than three times as much greenhouse gas as would have been produced by generating electricity by burning oil.

Climate scientists would have us believe there is no doubt about the basics of global warming and the time for action is now. The recent spate of large revisions of the facts tells a different story. Yet politicians are still being pressed to do the impossible: modify the huge, chaotic system that is the earth's climate in ways guaranteed to be beneficial for all.