Does Amazon deforestation mean trouble for California?

Deforestation of the Amazon rainforest could lead to drastic loss of rainfall in the United States, researchers led by Princeton University have found. On November 15 The Journal of Climate published their article ‘Simulated Changes in Northwest U.S. Climate in Response to Amazon Deforestation’ in which they predict that the loss of the entire rainforest would result in a 10-20% loss of precipitation across the coastal northwest United States. This would, among other things, drastically reduce the water available in California, the nation’s highest producer of food and dairy products over the past 50 years.

One of the potential consequences of climate change is the deterioration of tropical ecosystems, which is one of the reasons why these researchers focused on the Amazon in particular. The Amazon has been used before to provide insight into the wider effects and mechanisms of climate change by studying El Niño events, extreme weather patterns in the Eastern Pacific due to natural warming of the water.

A common problem in the past, however, has been the imprecision of the large scale used in the mapping of grids in the forest, sometimes as large as 200km a side. This study rectified this by using the Ocean-Land-Atmosphere Model and a fine-resolution grid, between 25-50km, to investigate how the removal of different grids affected precipitation.

The disaster scenario of a completely deforested Amazon is unlikely, as the researchers themselves freely admit, especially as the average rate of deforestation has actually been decreasing on average over the past five years. However, their research still takes an important step in demonstrating the wider reaching potential economic and physical implications of climate change. Quantifying the services that we receive from ecosystems is a controversial topic, but studies like this could potentially generate a more widespread interest in protecting one of the most biodiverse places on the planet.

Read more at: http://journals.ametsoc.org/doi/pdf/10.1175/JCLI-D-12-00775.1