Johan Rockström, climate scientist: ‘We need to reduce red meat consumption in the rich parts of the world’

Swedish scientist Johan Rockström, 58, predicts a future of many shadows and some light. On the one hand, he considers it inevitable that global warming caused by human action will exceed the limit established in the Paris Agreements of 2015, but he also believes that there is available knowledge and tools to avoid a complete catastrophe. This, however, will require radical changes in the economy and in daily life.

Rockström, director of the Potsdam Institute for Climate Impact Research in Germany, a professor at Stockholm University and chief scientist at Conservation International, is best known for his work on “planetary boundaries,” a framework that identifies nine processes essential to maintaining the planet’s stability. They include freshwater use, ozone depletion and biodiversity loss. Each of these systems has what he calls “tipping points” — critical moments when processes can be thrown off balance by rising temperatures.

Winner of the 2024 Virchow Prize — an international award recognizing exceptional contributions to promoting global health — alongside Lucy Gilson, the climate expert spoke to EL PAÍS via video call from Potsdam.

Question: The Virchow Prize recognizes your contribution to both planetary and human health. Do you think these two elements are intertwined?

Answer: Yes, definitely. We have so much scientific evidence today that breaching these planetary boundaries has direct human impacts. At the Potsdam Institute, we do a lot of research, for example, on the impact of heat waves on human health and on food insecurity related to water scarcity caused by ecosystem change. We have eight to nine million people dying prematurely each year because of air pollution. So there’s a very tight link between planetary health and human health.

Q: Your most famous scientific idea is the framework of planetary boundaries and tipping points. What happens if they are exceeded?

A: A healthy planet is able to buffer and dampen and cool itself. When we burn fossil fuels, however, 90% of the heat that comes from this process is absorbed by the ocean, 25% of the carbon dioxide is absorbed by the ocean, and another 25% is absorbed through photosynthesis in intact forest systems on land. If the Amazon rainforest, for example, passes the tipping point, it will shift into a new state that is more like a savannah, and it would then release a lot of carbon, it would damage the geological cycle, and it will major damaging impacts and reinforce warming. The planetary boundaries are there to protect us. Five of these 16 tipping points are likely to be crossed at a global mean surface temperature rise of 1.5 degrees Celsius. That is why we set a climate planetary boundary slightly below 1.5ºC.

Q: Of these systems, you have mentioned on other occasions that there are some that are on the brink of the precipice.

A: Yes, these five are very dramatic. You are talking about the Greenland ice sheet and the West Antarctic ice sheet, the abrupt thawing of permafrost, the collapse of all tropical coral reef systems, which provide livelihoods for hundreds of millions of people around the world, and the collapse of the Labrador sea current. These five systems are likely to cross their tipping points already at 1.5 degrees of warming and we are talking about impacts across the entire world. We are approaching a point where we are at risk of triggering a series of tipping points.

Q: Many scientists say that it is already impossible to avoid 1.5 degrees of warming. This means that those systems you mentioned will inevitably pass the tipping point, right?

A: 1.5 is the median assessment along quite a wide uncertainty range. Many scientists have concluded that it’s not possible any more to stay under 1.5. This means, and I also draw this conclusion, that our only chance today is to stay at 1.5 after we have overshot it, meaning we will very likely breach 1.5 degrees Celsius somewhere between 2030 and 2035, and then we will have long period of overshoot of some 30 to 40 years and potentially come back to 1.5 by the end of this century, around 2100. The overshoot at best will be somewhere between 1.6 to 1.8 degrees Celsius. And the question is: will the Greenland ice sheet cope with this?

Q: And the answer?

A: The answer is that we don’t know. There are two papers from the Potsdam Institute that indicate they may actually cope if that overshoot period is short. But we cannot be sure that we can avoid the permanent crossing of tipping points during that period. That is of course very scary, but it’s also another reason why we must minimize overshoot at all costs.

We know with 100% certainty that it will get worse before it gets better. The years 2023 and 2024 are the worst years for humanity in terms of extreme weather events”

Q: Will the planet be able to return to 1.5 degrees after the overshoot?

A: This requires phasing out fossil fuels. So it’s absolutely necessary to reach zero emissions by 2050. But it also means that we need to get back to the safe space of planetary boundaries. We need the ocean and forest systems intact so that they can still absorb carbon dioxide. We need biodiversity. We need fresh water. We need land. We need nitrogen and phosphorus to be on the safe side and not, as we are now, on the dangerous side. We will not get back after the overshoot if we do not address the other boundaries as well. In that sense we are facing a very, very dangerous future because so far we have not solved any of these boundaries.

Q: So, for several decades, we will live with the already inevitable consequences of the imbalance of the planet.

A: In science it is very rare to be able to talk of zero uncertainty and this is one of those few cases. We know with 100% certainty that it will get worse before it gets better. The years 2023 and 2024 are the worst years for humanity in terms of extreme weather events. We have never had so many hurricanes, landslides, droughts, floods and deadly heat waves. It is a magnitude that we haven’t seen before. And this is just the beginning. For every tenth of a degree, extreme events increase and become more fierce. Hurricane Milton was the strongest ever recorded to hit Florida. We knew this was going to happen. But what we can also say now is that it will happen again and it will get worse.

Q: In addition to achieving zero emissions by 2050 and getting rid of fossil fuels, what are other key goals that humanity must achieve for the situation to eventually improve?

A: Number one is phasing out fossil fuels. Number two is transformation of the food system, which is the single largest cause for breaching planetary boundaries. The agricultural system is the single largest emitter of greenhouse gases across all economic sectors, responsible for somewhere between 25% and 30% of emissions. It is by far the main cause of biodiversity loss. It is by far the largest consumer of fresh water: 70% of water withdrawals from rivers, lakes and groundwater come from agriculture. And we also know that the overload of nitrogen and phosphorus is due to overuse of fertilizers. Land expansion is predominantly caused by agriculture. That is why fixing the food system is number one. The energy transition is number two, and then the circular economy.

Q: How do you approach such a far-reaching change?

A: What we need now is leadership and policies. We need to set prices that make it more expensive to destroy fresh water, air, oceans, biodiversity and climate. The largest subsidy to the global economy is that we allow the planet to be damaged for free without it being factored into consumer prices. We allow 50% of our gas emissions to be absorbed by the ocean and intact nature. This has massive implications. The ocean is becoming more and more acidic: pH levels have dropped by 30%. It causes massive loss of calcium carbonate, which is the fundamental building block of all skeletons and hard shells, from animal plankton to hard corals. And on land, it leads to an artificial acceleration of photosynthesis. That is a stres factor on all forms of vegetation.

We cannot have more agricultural land. And this has to be communicated in a constructive way to developing countries in the Global South”

Q: In terms of nutrition, what tops the list of changes?

A: Reducing livestock numbers, particularly in the intensive red meat industry. We need to reduce red meat consumption in the rich parts of the world. Instead of eating 600 to 700 grams per person per week, we should go down to something like 150 grams, which means going from three portions a week to one portion. That’s not very dramatic. But it’s a big transition toward more plant-based diets, a flexitarian diet. We’re talking about less ploughing, more circular use of nutrients, less industrially produced fertilizers, a reduction in water use, more intercropping, much more diverse landscape-based ecological intensification.

Q: And the poor countries?

A: We cannot have more agricultural land. And this has to be communicated in a constructive way to developing countries in the Global South. Countries like Brazil, Colombia, Venezuela, the Democratic Republic of the Congo or Indonesia must be supported financially so that they can become stewards of these large forest systems, what I call global commons, so that they generate a service to humanity by keeping these systems intact. And therefore they should be entitled to compensation.

Q: And how is this compensation regulated?

A: Nobody is suggesting that it should be somehow something regulated by others. The Amazon is Brazilian property. However, the world has the right to tell President Lula that he cannot allow us to lose this system because it will have an impact on the climate. Then the world will have to compensate him in exchange for promising to keep the forest intact. And we know how to do this. We already have a legal treaty for Antarctica, we have a legal treaty for the high seas and we have a legal treaty for outer space. These are legal treaties that all countries in the world are part of and that govern systems that are outside national jurisdictions. We need exactly the same for the tipping point systems.

Q: These actions, such as limiting agriculture, imply changes in economic systems. Can we aim for economic development without destroying the planet?

A: I support the idea of alternatives to our current neoclassical GDP-based model of global economic growth. However, the situation is so urgent that I don't see the solution as reforming the global economy into a new system and then solving the climate problem. I think we have to solve the problem within our current economic system. Make the neoclassical GDP-based economic paradigm work for us, not against us. This is possible by putting a price on everything that harms planetary boundaries. And the first step is, of course, putting a price on carbon. We have extensive research on how to do that and what the cost is. The European Union has the highest carbon price of all.

But the economy is not everything. Sometimes we think that it is the only thing that moves the world, and it’s not. For example, Norway said that by 2035 it will no longer allow internal combustion engines in the economy. Period. That has nothing to do with the economics.

We know what policies are needed. The problem is very simple: interests. There are too many actors who still benefit from staying in the old system”

Q: Scientists have been warning for years about many of the dangers we face now. Even though we have more knowledge than ever before, it rarely translates into political action. How can that be corrected?

A: We know what policies are needed. The problem is very simple: interests. There are too many actors who still benefit from staying in the old system. But even the most willing and best informed politicians make the mistake of seeing the climate crisis as just another problem among all the other problems. You have the climate crisis, then the war in Ukraine, then jobs, then inflation, then crime, and then migration and everything else. But they are not equal. Political leaders need to recognize that the planet comes first. That is the force majeure, that is the point of emergency. There is no room to discuss peace or security or health, or whatever you want to discuss as an aspiration for the future of humanity, if we cross the tipping points in the Earth system.

Sign up for our weekly newsletter to get more English-language news coverage from EL PAÍS USA Edition