The Prime Minister John Howard seems to get all the breaks. There was Tampa a couple of federal elections ago, then the terrorists bomb plot uncovered the day he introduced the IR legislation into parliament and now, the week the Prime Minister gets to host the Asia-Pacific Partnership on Clean Development and Climate, science journal Nature publishes a paper attacking “one of Kyoto’s conceptual cores“.
Under Kyoto, trees are good. Forests count as a sink for carbon, with carbon credits for trading being available to those who plant forests in accordance with Kyoto rules.
But carbon dioxide is not the only greenhouse gas, there are a few others including methane. Methane is about 20 times more potent than carbon dioxide as a warming gas.
The new study led by Frank Keppler of the Max Planck Institute in Germany has found living plants emit methane and calculates that all the world’s living vegetation (forests included!) could emit between 62 and 236 million tonne of methane per year. This is apparently equivalent to between 10 and 30 per cent of all annual global emissions.
The finding is being hailed as an explanation as to why methane emissions had been reducing – by about 20 million tones a year during the 1990s. And I had been sure methane emissions were going up and up, click here for related blog piece with graph of atmospheric methane levels.
The reason methane levels are now thought to have been reducing during the 1990s is because we apparently cut down 12 per cent of the world’s tropical forests during that decade, click here.
How have global methane emission being trending over the last 5 years?
How does planting a forest compare with defrosting a Siberian swamp – in terms of adding methane to the atmosphere?
What are the implications for Kyoto participants if forests are a source rather than a sink for greenhouse gases?
Australia, a Kyoto dissident, is nevertheless on target to meet its Kyoto targets because it has banned broad scale trees clearing. But hang-on, maybe it will now be OK to clear regrowth?
So many questions!
I had avoided the issue of carbon trading and targets in the piece I recently wrote for the Courier-Mail about the the Asia-Pacific Partnership on Clean Development and Climate, click here. It looks like the rules might have to be rewritten now anyway.
Imagine trees emitting methane! Who said the science was settled?
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.