Mit dem Kopf voran

24.08.2006 um 09:54 Uhr

Lieber keine Bäume pflanzen?

Die Klimaforschung kommt immer wieder mit bemerkenswerten Neuigkeiten in die Schlagzeilen. So berichtet der Artikel "The Methan Mystery" im Augustheft des Wissenschaftsmagazins Nature über neue Forschungsergebnisse, nach denen lebende Pflanzen im globalen Maßstab so große Mengen des besonders wirksamen Klimagases Methan freisetzen, dass eine Überprüfung des Anteils der Klimagasemissionen durch den Menschen am Treibhauseffekt ratsam erscheint:

It took 18 years, but Paul Crutzen and Eugenio Sanhueza finally found a use for their data. In 1988, the two atmospheric chemists had discovered large amounts of the greenhouse gas methane building up at night over Venezuela. This March, they dusted off their data and used them to calculate a surprising number: that the world's tropical savannahs may produce 30 million to 60 million tonnes of methane each year1.

Remarkably, that number is similar to one reported in January, when a German chemist announced that living plants give off methane2. His claim rattled many, because textbooks hold that methane is produced from organic matter decaying in oxygen-free environments, not from living plants. If true, his finding could account for a substantial fraction of the methane entering the atmosphere — potentially throwing off calculations of how much humans contribute.