Forests under increasing stress from climate change

The International Union of Forest Research Organisations (IUFRO) says forests could release vast amounts of carbon if temperatures rise 2.5C (4.5F) above pre-industrial levels in a report released today.

Compiled by 35 leading forestry scientists, the report provides what is described as the first global assessment of the ability of forests to adapt to climate change.

“We normally think of forests as putting the brakes on global warming,” commented Professor Risto Seppala from the Finnish Forest Research Institute, who chaired the report’s expert panel.

“But over the next few decades, damage induced by climate change could cause forests to release huge quantities of carbon and create a situation in which they do more to accelerate warming than to slow it down.”

While deforestation is responsible for about 20% of greenhouse gas emissions from human activities, forests currently absorb more carbon than they emit.

But the problem is that the balance could shift as the planet warms, the report concludes, and the sequestration service provided by the forest biomes “could be lost entirely if the Earth heats up by 2.5C or more”.

Commenting on the report, Dr Abigail Entwistle, Director of Science at Fauna & Flora International, said: “This study reinforces the recognition by an increasing number of scientists that without a drastic cut in emissions we could reach a ‘tipping point’, after which a self-reinforcing spiral of climate change could kick in. This is because the changing climate will lead to wide scale destruction of the world’s forest habitats, and a resulting massive release of carbon dioxide into the atmosphere.”

“Interestingly, the report also highlights the vulnerability of the northern coniferous forests, and the massive carbon stocks they contain. Without further efforts to protect these forests, their destruction will release significant levels of carbon dioxide into the atmosphere and thus contribute to further climate change.”