The New York Times blog ‘Green’ published a post last week by Justin Gillis discussing the so-called Amazon dieback scenario. Computer analysis led by Peter M. Cox of the University of Exeter in the UK found that the Amazon rainforest would continue to take up carbon from the atmosphere (and thus act as a carbon sink) until around 2050. However, warmer temperatures and water stress resulting from climate change in the region would eventually cause huge dieback of the Amazon rainforest (which would result in the Amazon forest becoming a carbon source – that is emitting more carbon then it sequesters).
While a number of scientists find Cox’s prediction too pessimistic, the severe droughts of the past decade are indeed worrying. The drought of 2010 is thought to have been even larger then the prolonged drought of 2005 that killed numerous large trees in the region. Two "once a century" droughts in five years… While the triggers of the 2010 drought are still being studied, researchers say that the 2005 drought could have been caused by high Atlantic Ocean temperatures – a possible result of anthropogenic greenhouse gas emissions.
These findings lead Gillis to the logical question: “Could the great dieback predicted for midcentury already be starting?”
While scientists are reluctant to answer this question, there is a general agreement that if the Amazon starts to experience such frequent droughts “all bets are off”.
While a number of scientists find Cox’s prediction too pessimistic, the severe droughts of the past decade are indeed worrying. The drought of 2010 is thought to have been even larger then the prolonged drought of 2005 that killed numerous large trees in the region. Two "once a century" droughts in five years… While the triggers of the 2010 drought are still being studied, researchers say that the 2005 drought could have been caused by high Atlantic Ocean temperatures – a possible result of anthropogenic greenhouse gas emissions.
These findings lead Gillis to the logical question: “Could the great dieback predicted for midcentury already be starting?”
While scientists are reluctant to answer this question, there is a general agreement that if the Amazon starts to experience such frequent droughts “all bets are off”.
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| A field once covered by the forest is prepared for soybean cultivation in Brazil. (The New York Times, Green Blog) |
what is the full reference for the Cox study?
ReplyDeletePeter M. Cox et al (2000), Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model, Nature 408(9):184-187
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