Swedish researchers' alarm: Earth stops "buffering"

 

Climate change
Unknown factor affecting the earth: Can't explain it

Jonathan Jeppsson

Published 12.25
 

Quick version

• In 2023, the warmest year on record, there was a sharp decline in the ability of the world's land areas to absorb carbon dioxide.
• Johan Rockström expresses concern that the earth's ability to function as a buffer against climate change is weakening, which may explain the accelerating warming. He points out that global and national climate policy can be drastically affected by these changes.
• Additional factors such as reduced cooling particles in the atmosphere and extreme El Niño may also contribute to the warming acceleration, making the situation even more complex and serious for global climate policy.
  

Ten years ago, something happened - global warming began to accelerate.

Scientists do not yet have the full picture of why. But there are theories that worry.

- We can't really explain it yet, but the risk is that the earth is weakening in its ability to

During the summer, a surprising report came.

It found that in 2023, the hottest year on record, the ability of the world's land areas to absorb carbon dioxide had temporarily collapsed. The study was able to establish that forests, plants and soil, which are normally a huge carbon sink and absorb large amounts of carbon dioxide, took up almost alls under året. no carbon at all during the year.

Of course, the carbon dioxide that was not absorbed stayed in the atmosphere - but how serious was it really?

- It is very serious, but unfortunately not surprising. We have seen this coming for a long time, says Johan Rockström, professor of environmental science and director of the Potsdam Institute for Climate Impact Research.

"Extremely worrying"

Although the carbon sinks' uptake varies greatly between years, partly due to weather phenomena such as El Niño, there is much evidence that this is part of a long-term shift.

- What we see now is a trend over the last five to ten years, which unfortunately points in a direction where most large forest systems show signs of losing their carbon absorption capacity. And that is extremely worrying for two reasons: One is, of course, that it is a sign that the entire earth system is beginning to show signs of weakening, that we are losing what we call resilience, its buffering capacity, says Johan Rockström.

- And that is what causes further concern, namely that we are currently seeing a tendency towards an acceleration of the rate of warming on earth. We can't really explain it yet, there isn't an unequivocal answer, but the risk is that the main candidate for why the rate of warming is increasing is that the Earth is weakening in its ability to buffer - and this could then be a first sign.

"Most large forest systems show signs of losing their carbon absorption capacity," says environmental scientist Johan Rockström. More than two-thirds of Sweden's total area consists of forest. Photo: Helena Landstedt/TT

"Looks bad"

That in itself would therefore mean that the temperature rise risks going faster. But is there any evidence that the forests are really losing their ability to absorb and store carbon dioxide? According to Johan Rockström, the answer there is an unequivocal "yes".

- We have so much empirical evidence that forest fires are increasing, droughts are increasing, deforestation is increasing and disease patterns in the forests are increasing. Right now, as you and I sit and talk, a record number of fires are going on in the Amazon. If you collect all this information in one place, it leads to the conclusion that it looks bad.

Images show carbon dioxide emissions from fires in California over a three-day period from September 12 to 14, 2020. It shows three-day averages of carbon dioxide concentrations about 5 kilometers up in the atmosphere. Photo: AP

All climate policy, according to Rockström, is based on the fact that we have agreed to keep global warming to 1.5 degrees. Science's climate models have been translated into a global carbon dioxide budget, which in turn forms the basis for, for example, the Swedish climate law. But all the models assume that the carbon sink for forests and land continues to be intact.

- Here we have the big problem with direct consequences on the pursued climate policy. Now we see that the models are wrong when reality indicates that this carbon sink may disappear. If that carbon sink disappears, then large parts of the budget will disappear. And then the possibilities for the Swedish climate act to work disappear.

 

         

Johan Rockström, environmental scientist. Photo: Aftonbladet / Margareta Bloom Sandebäck

Must accelerate

This has major consequences for Swedish forest policy, says Rockström. And the alarms are now coming from several directions.

- The other day, Romina Pourmokthari was interviewed about the fact that Sweden will very likely miss the climate goals, especially the goal regarding forests and land. I was already in dialogue with the Finnish government two years ago and they are in the same boat. The Finnish forest is no longer the large carbon sink that Finnish climate policy had anticipated, but risks becoming a net source. The Canadian authorities are also equally concerned.

- The conclusion is that we must accelerate the way away from coal, oil and gas. This is not the time to lower the level of ambition. This is the opportunity to increase the level of ambition.

Cooling particles disappear

But there may be more reasons why the warming has accelerated than that the forests and the land are about to lose their capacity. One of them could be that we reduce the amount of cooling particles in the atmosphere.

- It is a paradox that we clean the air faster than we reduce the emissions of greenhouse gases from oil, coal and gas, so that warming gases continue to increase while the cooling sulfates and nitrates from air pollution decrease. And then, of course, you also cannot rule out that it may have to do with albedo changes (how much sunlight is reflected from the earth's surface, editor's note). It may also have to do with ocean dynamics.

- So there are several possible explanations, probably several factors interact. Additionally, 2023 was an extreme El Niño year, resulting in us experiencing 1.5 degrees for the first time. But despite the uncertainty, is there reason to be worried? The answer is with one hundred percent certainty yes, because at least it cannot be caused by our increasing the rate of greenhouse gas emissions. We don't do that. We are on the way to bending the curve.

Filled up the system

It would have been a partly different matter, says Johan Rockström, if it had been the case that we continued to increase the burning of coal, oil and gas and that the earth continued to follow the linear relationship between emissions and warming that we have had since 1970. But that is how it is it doesn't.

- Something is very likely wrong.

- Regardless of the explanation, it is a matter of concern because it is a signal that the earth tolerates less pressure. We cannot rule out that we have reached what I call a saturation point. That we have filled up the entire system.