Solutions to climate change: Johan Rockström on rainforest conservation

Why are healthy forests losing their ability to store carbon?

“In total carbon uptake, we’re seeing very strong signs of decline… this is related to forest fires. It’s related to disease outbreaks like bark beetle. It’s also related to unsustainable timber extraction. So it’s a combination of temperatures rising, water scarcity triggering more disease and more fire, and overall stress on photosynthesis.

Forests in a healthy state respond to the climate crisis by growing faster. But what we’re starting to understand now is that there’s a limit to that capacity because although forest grows faster, it’s not positive. It’s a stress response. And that stress response makes the trees more brittle, and it makes them more subject to abrupt crisis shocks like fires and droughts.

When we see the positive signs of a more carbon uptake in forests, of course we should thank the forest for this phenomenal service to humanity. But at the same time, we should recognize that this is putting pressure on the system. It’s not something that we can just lay back and say, “Well, isn’t that fantastic? The forests are doing this under stress.”

What is the current state of tropical deforestation, and how close is the tipping point?

“Tropical forest deforestation remains at an unacceptably high level. It’s a deep concern. And we’re coming very close to tipping points, to irreversible collapse of forest systems.

Deforestation continues. And as we mentioned earlier, we are today at roughly 18% of forest lost so far. And just a few weeks back, colleagues at the Potsdam Institute published the latest scientific paper of risk in the Amazon rainforest, showing that if we lose more than 22% of forest cover then the system is likely to cross a tipping point, meaning we can’t come back.  

Not long ago we thought that the rainforest systems could cope with up to three degrees Celsius of warming, because that’s what the science indicated… But now we understand that we were wrong, and that the combination of losing biodiversity, changing hydrology and, in particular, deforestation reduces the forest system’s health and strength.” 

“And today the assessment is that you exceed 20% of forest canopy loss, and you’re already in danger when you exceed 1.5°C. Remember, we are essentially at 1.5°C. And we will be breaching the 1.5°C limit more permanently already within the next five to ten years.

What keeps a rainforest in a rainforest state is its capacity to generate 40% of its own moisture recycling. And when you open that system—too much deforestation—you lose too much biodiversity… that feedback means that the system goes from self-moistening, when it has this convective rainfall generator, to become self-drying. And it simply moves into a savanna mode.

We are so close to crossing a tipping point in the Amazon rainforest… and what that means is that the system would cross the threshold and irreversibly move towards becoming degraded bush savanna.”

What happens if the Amazon crosses that tipping point?

“It’s not like a tsunami. It’s not a 24-hour collapse. It would probably take 100 years… 

And you would lose the ecological and ecosystem services to all the Indigenous communities and societies inside, and also neighboring the biome. And you would then, after 100 years, end up in this degraded end state.

So even though it would take 100 years, some people may say, “it’s so far away, so we might not have to worry.” Well, I can tell you, we need to worry because if we press the on button, you would see an accelerated rate of losing more and more species biomass, more carbon emissions, accelerated warming, loss of fresh water. 

São Paulo would be affected. Argentina would be affected. You would have a losing journey along the entire path until you too end up in that end state.”

Why is rainforest conservation work like Cool Earth’s so important?

“For so many reasons.

One reason is just because we know we’ve come to a point when we cannot allow ourselves to lose more forest. We have to halt that loss. And we know that there are multiple pressures on the system. We know that 91% of the deforestation in the Amazon is illegal today. So all forms of support for governance, for policing, for responsible stewardship are fundamentally important.

Secondly, I think it’s important to recognise that we also have so much evidence. You cannot sit back and wait until some magical wand comes down and top-down solves everything.”

“We know that big transformative positive changes require multiple positive tipping points occurring from below, and Cool Earth contributes to that. And when these add up, they can be large enough to tip over the logic in the broader scheme of things.

Because we know—and that’s our kind of key card that we always know that we can and should play more often—is that by preserving forests, by investing in sustainability, we become winners. You come out with healthier, more resilient, more prosperous livelihoods. So it’s not a sacrifice. It is a winning journey.

And Cool Earth is part of that winning journey. And when doing it persistently and stubbornly across larger and larger communities and areas, it can tip over into becoming the winning logic.

And I think that is what, in my mind, actors like Cool Earth contribute with, which is fundamental.”

From planetary science to direct cash

Rockström’s science shows the Amazon is close to a tipping point it can’t come back from. His science also shows that Indigenous-led land stays standing. Put those together and unconditional cash to the people already protecting rainforest is one of the most scientifically grounded solutions to climate change we have, at a fraction of the cost of trying to fix a collapsed system later. 

It’s why we back Indigenous communities directly, community by community, across the Peruvian Amazon, Papua New Guinea and the Congo.

We’re at 18% forest loss in the Amazon. The tipping point is 22%. We have a narrow window, and we know what closes it: backing the people already keeping rainforest standing.