On a hillside overlooking cabbage fields outside the northern Thai city of Chiang Mai, a drone’s rotors begin to whir, lifting it over a patch of forest.
It moves back and forth atop the rich canopy, transmitting photos to be knitted into a 3D model that reveals the woodland’s health and helps estimate how much carbon it can absorb.
Drones are part of an increasingly sophisticated arsenal used by scientists to understand forests and their role in the battle against climate change.
The basic premise is simple: woodlands suck in and store carbon dioxide, the greenhouse gas that is the largest contributor to climate change.
But how much they absorb is a complicated question.
A forest’s size is a key part of the answer – and deforestation has caused tree cover to fall 12 percent globally since 2000, according to Global Forest Watch.
But composition is also important: different…
