Dangerous climate change ‘to kill Amazon rainforest’


Global warming will wreck attempts to save the Amazon rainforest, reports the UK’s Guardian newspaper.

It says a study presented at a major climate science conference in Denmark has predicted that one-third of its trees will be killed by even modest temperature rises.

The research, by some of Britain’s leading experts on climate change, shows that even severe cuts in deforestation and carbon emissions will fail to save the emblematic South American jungle, the destruction of which has become a powerful symbol of human impact on the planet.

Up to 85% of the forest could be lost if spiralling greenhouse gas emissions are not brought under control, the experts said.

But even under the most optimistic climate change scenarios, the destruction of large parts of the forest is “irreversible”.

Vicky Pope, of the Met Office’s Hadley Centre, which carried out the study, said: “The impacts of climate change on the Amazon are much worse than we thought.

“As temperatures rise quickly over the coming century, the damage to the forest won’t be obvious straight away but we could be storing up trouble for the future.”

Tim Lenton, a climate expert at the University of East Anglia, called the study, unveiled at the University of Copenhagen gathering, a “bombshell”.

He said: “When I was young I thought chopping down the trees would destroy the forest, but now it seems that climate change will deliver the killer blow.”

The study, which has been submitted to the journal Nature Geoscience, used computer models to investigate how the Amazon would respond to future temperature rises.

It found that a 2C (3.6F) rise above pre-industrial levels, widely considered the best case global warming scenario and the target for ambitious international plans to curb emissions, would still see 20-40% of the Amazon die off within 100 years.

A 3C (5.4F) rise would see 75% of the forest destroyed by drought over the following century, while a 4C (7.2F) rise would kill 85%.

“The forest as we know it would effectively be gone,” Dr Pope said.

Experts had previously predicted that global warming could cause significant “die-back” of the Amazon.

The new research is the first to quantify the long-term effect.

Source: Guardian newspaper

Date: 12/03/2009

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Forests face fiery future, warn UK’s Met Office


Climate change is putting further pressure on forests, with less rain and increased drought leading to increased risk from fire, the UK Met Office’s Hadley Centre has warned.

Deforestation is already a major cause of carbon emissions, it warns, and is currently estimated to exceed those from the global transport sector.

Hadley Centre scientists attending the UN climate conference in Poznan claimed that new estimates of future deforestation in critical regions, such as the Amazon, were much larger than those used by the Inter-governmental Panel on Climate Change (IPCC).

With no controls on deforestation, the area of forest lost could be five times greater than outlined in the IPCC’s Special Report Emissions Scenarios (SRES).

The researchers warned that even with effective governance the loss could be double.

Dr Vicky Pope, head of climate advice at the Met Office, said: “In addition to man-made deforestation, climate change may cause the ‘die-back’ of the Amazonian forest.

“However, deliberate deforestation in Amazonia is likely to have a bigger impact in the short term.”

Climate scientists are assessing the potential impacts of ongoing deforestation on climate change and the extent to which reducing deforestation could contribute to stabilising greenhouse gas concentrations.

By avoiding deforestation during the early part of this century, carbon emissions would be reduced by up to 27 gigatonnes by 2050.

In a double benefit, preservation of the forest would maintain a carbon sink from carbon dioxide fertilisation of photosynthesis, which is worth a further four gigatonnes by 2050.

Climate change is also expected to put further pressure on forests, the UK researchers warn.

They said that in previous droughts, such as 2005, fires used for forest clearance became uncontrolled and larger areas were burnt through this “fire leakage”.

Climate change is also likely to reduce rainfall in the region.

The researchers suggest that even if this does not directly damage plants, it is likely to increase the risk of fire leakage which would magnify the impact of deforestation.

Source: UK Met Office press release

Date: 10/12/2008

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