Forests could turn from CO2 “sinks” to “sources”
April 17th, 2009 by Jim JustThe first global assessment of the ability of forests to adapt to climate change finds that the forests that today soak up a quarter of carbon pollution spewed into the atmosphere could soon become a net source of CO2 if Earth’s surface warms by another two degrees Celsius (3.6 degrees Fahrenheit). The study, “Adaptation of Forests and People to Climate Change – A Global Assessment” was coordinated by the Vienna-based International Union of Forest Research Organizations (IUFRO).
With a global warming of 2.5 C (4.5 F) compared to pre-industrial times, the forest ecosystems would begin to turn into a net source of carbon, adding significantly to emissions from fossil fuels and deforestation. Any increase of more than 2.0 C, the panel warned, would unleash a maelstrom of human misery, including drought, famine, disease and forced migration. A growing number of climate scientists are saying that this threshold is likely to be crossed no matter what actions are taken.
Healthy forests – especially those in the tropics – take up far more of the greenhouse gas than they give off. While warming will increase growth in boreal forests, the positive effects on northern forests will be greatly outweighed by the negative impacts on tropical forest ecosystems.
The full press release in English is available here. The full report “Adaptation of Forests and People to Climate Change – A Global Assessment Report” can be downloaded here.