40 | New Scientist | 2 November 2019
Rivers in
the sky
We talk a lot about deforestation’s role in climate
change. But its impact on Earth’s water recycling
system is just as critical, finds Fred Pearce
G
ERARD MOSS is a bush pilot in the
swashbuckling tradition. Born in
the UK and raised in Switzerland,
he had flown twice round the world in his
single-engine plane before he set out on a
new journey, to track rain clouds across the
Amazon in his adopted home of Brazil.
Local scientists had an idea: that the forests
of the Amazon were the continent’s biggest
rainmakers; that most of the moisture in the
clouds had been taken up and recycled back
into the air five or six times by its 400 billion
or so trees. Take away the trees, reasoned
biologists such as Antonio Nobre, then
of the National Institute of Amazonian
Research in Manaus, and the rains would
die. The Amazon basin would turn to desert.
But with the rainforest largely a black holeFeatures