Thursday, March 19, 2015

Amazon Rainforest Is Taking Up a Third Less Carbon Than a Decade Ago

The Amazon canopy at dawn, in Brazil. (Credit: Peter van der Sleen) Click to Enlarge.
The Amazon is losing its capacity to absorb carbon from the atmosphere, reveals he most extensive land-based study of the Amazon to date.  From a peak of two billion tons of carbon dioxide each year in the 1990s, the net uptake by the forest has halved and is now for the first time being overtaken by fossil fuel emissions in Latin America.

The amount of carbon that the Amazon rainforest is absorbing from the atmosphere and storing each year has fallen by around a third in the last decade, says a new 30-year study by almost 100 researchers.

This decline in the Amazon carbon sink amounts to one billion tonnes of carbon dioxide - equivalent to over twice the UK's annual emissions, the researchers say.

If this pattern exists in other forests around the world, deeper cuts in human-caused carbon dioxide emissions are needed to meet climate targets, the researchers say.

Three billion trees

The Amazon rainforest is the largest rainforest in the world.  Spanning nine countries in South America, it's 25 times the size of the UK.

Using photosynthesis, the Amazon's three billion trees convert carbon dioxide, water and sunlight into the fuel they need to grow, locking up carbon in their trunks and branches.

As they grow, Amazon trees account for a quarter of the carbon dioxide absorbed by the land each year.  Studies suggest that as human-caused carbon dioxide emissions increase, forests will absorb and store more carbon, assuming they have enough water and nutrients to grow.

But the new study, published today in Nature, suggests the Amazon has passed saturation point for how much extra carbon it can take up.

Read more at Amazon Rainforest Is Taking Up a Third Less Carbon Than a Decade Ago

No comments:

Post a Comment