[ music ]
Narrator: Pulses of laser light. 300,000 per second
each one represented by a single leaf.
Flying above a protected area of a Brazilian rainforest,
NASA scientists measure changes in the canopy to understand how climate change affects
the amount of carbon stored in the Amazon’s mighty trees.
They flew the same transect of the forest three times over three years,
first comparing two fairly normal weather years, 2013 and 2014,
and then surveying again in 2016,
after a severe El Niño drought.
With trees more than 16 stories tall, airborne measurements capture changes
in forest structure not possible from the ground or from space.
Lighter areas, seen falling away here,
represent limbs and whole trees crashing to the ground
as a result of storms and environmental stress
As they fall, they take other trees with them.
In collaboration with Brazilian scientists,
the team also conducted ground surveys to measure the woody material
on the forest floor. They found that
80% of the carbon losses came from the death of larger trees.
But surprisingly, large trees were not hurt comparatively more by the drought
than were smaller trees, as had been previously suspected.
The team also surveyed areas of forest impacted by logging,
where even more dramatic changes can be seen.
Researchers will continue to analyze
the changing climate and human activity affect rainforests
and how much carbon these forests both take up – and release – to the atmosphere.
[ music fades ]