Amazon losses make climate change worse

More than one-tenth of trees in the Amazon rainforest have been removed since the 1960s, University research shows.

Widespread removal of trees has contributed to a rise in the amount of carbon dioxide in the atmosphere, increasing the potential impact of climate change.

Deforestation of the Amazon accounted for 1.5 per cent of the increase in carbon dioxide levels seen since the mid-nineteenth century.

This increased the total amount of carbon in the atmosphere only very slightly compared to fossil fuel emissions, which account for the vast majority of the increase.

Carbon storage

The study is the first to show the extent of Amazon deforestation by determining the impact humans have had on its ability to store carbon.

Had deforestation not taken place, the rainforest would contain 12 per cent more vegetation, and cover a much larger area.

Trees absorb carbon dioxide from the atmosphere in order to grow, which helps offset fossil fuel emissions, reducing the rate of climate change.

Modelling deforestation

The team made maps to show what size the Amazon would be today if humans had not deforested large areas of it.

High-resolution satellite images have been available only since 2000, so the team made virtual models to work out how the rainforest changed in earlier decades.

Researchers used these to study how the loss of trees reduced the rainforest’s ability to absorb carbon.

Widespread destruction

Destruction of large areas of the Amazon impacts on the biodiversity of the rainforest and could lead to the loss of many animal and plant species.

The study, published in the journal Geophysical Research Letters, was funded by the Natural Environment Research Council.

Our study indicates that the impact of large-scale deforestation on the Amazon carbon balance has been partially offset by ongoing regrowth of vegetation, despite sustained human activity.

Dr Jean-François ExbrayatSchool of GeoSciences