Picture Earth's lungs… struggling to breathe.
New research says an area the size of France worth of tropical forest has crossed a critical heat line — and photosynthesis, the very process trees use to pull carbon out of the sky, is starting to fail.
This isn't a future warning.
It's happening right now.
Scientists at EPFL tracked satellite temperatures across tropical canopies from 2001 to 2020.
Then cross-referenced them against heat tolerance data for 200 plant species.
The finding stopped them cold.
Stay with that last one.
15 degrees used to be the buffer.
Now heat, drought, and extreme weather are eating into it.
Past the threshold, the proteins that run photosynthesis literally start to break down.
Trees make less energy.
Grow slower.
Get sicker.
Some die.
👉 Less photosynthesis means less carbon dioxide pulled out of the atmosphere — right when the planet needs forests to absorb more, not less.
Researchers project the danger zone could nearly double by mid-century, and by 2100 could swallow 160 million hectares — roughly the size of South Africa.
That's not just about trees.
Weakened forests release less water vapour, which can fuel droughts elsewhere.
Fewer heat-sensitive species survive, reshaping habitats for birds, insects, and mammals that depend on them.
Some heat-tolerant species could gradually replace the ones dying off.
Nature adapting in real time.
But scientists aren't sure adaptation can outrun the pace of warming.
The clock is ticking faster than the forest can evolve.
That's all for now!
