Will deforestation and warming push the Amazon to a tipping point?

For more than 40 years, Carlos A. Nobre has studied his nation’s most magnificent natural asset — the Amazon rainforest — and its vital role in the global climate system. And for the better part of a year, Nobre has watched with alarm as his country’s nationalist president, Jair Bolsonaro, has issued full-throated calls for the further development of the Amazon, leading in recent weeks to a huge outbreak of fires from the illegal clearing and burning of the forest.

In an interview with Yale Environment 360, Nobre, a senior researcher at the University of Saõ Paulo’s Institute for Advanced Studies, talks about an alarming tipping point now bearing down at which a combination of deforestation and climate change would transform much of the Amazon into a savanna ecosystem, with dire effects on the world’s climate system. But Nobre also discusses solutions he says could quickly halt new deforestation in the Amazon, including putting pressure on the global agribusiness firms driving the destruction; launching low-cost regeneration projects on vast tracts of degraded rainforest; and improving soybean yields on croplands already carved out of the forest.

“The pressure to bring to bear is on agribusiness, and this is happening,” says Nobre. “If companies pressed for a deforestation-free supply chain are very rigorous about that, I think deforestation will come to zero in less than five years.”

Yale Environment 360: The degradation of the Amazon has been ongoing for several decades. How much worse has it gotten since President Bolsonaro came to power?

Carlos Nobre: Unfortunately, it’s getting worse because deforestation rates have increased, but also because fires have increased very rapidly in the last couple of months. Deforestation came down 75 percent from 2005 to 2014. Brazil was really going toward a zero-deforestation policy, and then it started reverting back in 2015, 2016, 2017, and then bigger deforestation increments in 2018. Now, 2019 seems to be a peak. It’s very likely to be more than a 30 percent deforestation increase from 2018 to 2019. And fires since January have more than doubled in the Brazilian Amazon, compared to the same period in 2018, so something is getting out of control.

Of course, because of a worldwide outcry, the president just published an executive degree order to make it illegal to burn any forest, any biomass, for the next two months. But the major concern is that increases in deforestation and fires were supported philosophically, politically, and ideologically by the president and by the minister of environment. So that perhaps is even more worrisome than the figures themselves. The fact is that until a few days ago, the president and his ministers were all saying, “We have to bring ‘progress’ to the Amazon. There’s poverty. We have to continue opening up new areas of forest for cattle ranches, for agriculture, to exploit timber.” That’s inflammatory discourse. That’s what is really behind this explosion of people doing those things in the Amazon. According to Brazilian law, 80 percent of deforestation and nearly 100 percent of fires are illegal. But the people there, the environmental criminals, they felt free to do it — grabbing lands, razing lands for cattle ranchers — because they had the support of the president and many House members supporting that mode of development.

e360: What role did the cutting back of enforcement personnel on the government side play in the increase in destruction and fires?

Nobre: A total role. The fact that earlier we got a 75 percent reduction in deforestation and the corresponding reduction in fire, all had to do with law enforcement agents going deep into the forest, federal police intelligence knocking down organized crime groups illegally taking timber from the forest and selling it. And two things happened. First, Brazil is still going through a recession, the federal government’s budgets have been reduced, so there was less funding for those enforcement activities. But more important was the fact that even before taking office on January 1st, Bolsonaro was criticizing IBAMA [the federal environment agency] all the time.

IBAMA agents had confiscated machinery, tractors, and chainsaws in remote areas in the Amazon where people were cutting down the forest. According to Brazilian law, the agents are entitled to destroy the equipment. And then some people from the rural sector told Bolsonaro’s aides, and then he calls, himself, IBAMA in Pará state and prohibits them from destroying the equipment. So all those elements really convey impunity.

e360: I want to talk to you about tipping points and about this convergence of human development and climate change and its impact on the Amazon.

Nobre: There have been many, many studies about what climate change, deforestation, and increased vulnerability to forest fires might do to the Amazon system as a whole. In fact, I published a paper about this in Science in 1990 that said if we deforest parts of the Amazon, it will become a savanna. The post-deforestation climate will no longer be a very wet climate like the Amazon. It will become drier, it will have a much longer dry season, like the long dry seasons in the savannas in the tropics in Africa, South America, and Asia.

What we know today is that if we would have only deforestation — with zero climate change — that if you exceed 40 percent total deforested area in the Amazon, then you have a tipping point. About 60 to 70 percent of the Amazon forest would turn into a dry savanna, especially in the southern and northern Amazon, areas that now border savannas. Only the western Amazon near the Andes, which is very rainy, the forest will still be there. So that’s one tipping point — 40 percent deforested area.

Then we look at what climate change might do. We concluded that if the temperature in the Amazon increases up to 4 degrees Celsius (7 degrees Fahrenheit), this will mean a hydrological cycle change with less rain and a longer dry season. It’s the same mechanism — savannization. So if you put all the perspectives together — deforestation, global warming, increased vulnerability to forest fires — we conclude that with the current rate of global warming, if we exceed 20 to 25 percent deforestation, then we reach the tipping point and 50 to 60 percent of the Amazon forest would become a savanna. That’s why we are making this warning — today we already have 15 to 17 percent total deforestation in the Amazon. So at the current rates of deforestation, we are 20 to 30 years off from reaching this tipping point.

e360: So you’re basically saying that if the global climate was not warming, then the tipping point for the Amazon might be 40 percent deforestation, but with those other factors you mentioned — warming, fires — it is as low now as 20 to 25 percent.

Nobre: That’s correct. Exactly.

e360: And this vast hydrological system in the Amazon rainforest? Would it break down? Would it transform into something new? What happens to the hydrology?

Nobre: Rains will be more concentrated in the rainy season, a typical savanna climate level: six months of rain, six months of drought, and much hotter temperatures. In Central and South American savannas, maximum temperatures may easily reach 40 degrees centigrade (104 degrees F). But maximum temperatures in a forest like the Amazon are 34 degrees centigrade (93 degrees F). Forests have this cooling effect. And our calculations and many other studies show that the rainfall in and over these forests will decline between 20 and 25 percent. This will have a tremendous impact on all river hydrology, aquatic ecology. There will be less stream flow.

And we have studied what might be the remote impacts in South America. We found that a lot of that moisture travels south of the Amazon, parallel to the Andes. And that flow of moisture feeds a lot of the rain in southern Brazil, Paraguay, Uruguay, and parts of Argentina. And in many of these calculations and simulations, there will be a reduction of about 15 to 20 percent in the rainfall over that area I mentioned.

e360: If you have this savanna transformation of the forest, you would then have more fires, correct?

Nobre: Absolutely. Fires are part of the savanna ecology.

e360: So if this transformation were to occur, if 30 or 40 percent of the Amazon was thus transformed, at what point does the Amazon become a source of carbon instead of a sink?

Nobre: Many studies have looked at how strong the Amazon is as a carbon sink. The rates of removal of carbon dioxide from the atmosphere in the Amazon vary between 1 billion and 2 billion tons a year. Two billion tons is 5 percent of all carbon dioxide from human activities. On the other hand, because of deforestation and fires, the Amazon is a source of 500 million to 700 million tons of carbon a year. So if the deforestation continues, all that area is not acting as a carbon sink anymore. So in the next 20 to 30 years, the Amazon will become only a source of carbon.

e360: Given the dire situation in the Amazon now, what can be done? Under what scenario do you see the deforestation and fires being reversed, even under Bolsonaro? What kind of pressure or influence can be brought to bear?

Nobre: The pressure to bring to bear is on agribusiness, and this is happening. And I hope it will continue to happen. If you look at concerns of the major investment funds, which fund every business in Brazil, countries in Europe are threatening not to buy Brazilian products anymore — soy, beef, meat, and also leather. So if that pressure is brought to bear, in terms of sustainable consumption, that’s the most effective way. If companies pressed for a deforestation-free supply chain and are very rigorous about that, I think deforestation will come to zero in less than five years, because there is so much waste. There is so much poor agriculture, poor cattle ranching.

Productivity can be multiplied by three in livestock farming. There is so much potential to increase production without gutting one more tree. But that depends on consumers, that depends on the big investment funds, who do not want to be associated with deforestation. So I think we are in the moment to make economics put on the pressure. But then, of course, the Bolsonaro movement is very faithful to agribusiness and agribusiness is very faithful to Bolsonaro, and the day will certainly come that Brazil will lose markets and will weaken the economy, which is already weak.

The effectiveness of any measure has to come from the consumers — responsible, sustainable consumption is the best strategy to take the lead to zero deforestation. But more than that, also to the resurrection of the Amazon. The whole Amazon has at least 500,000 square kilometers either abandoned or degraded. So you could have a huge restoration project. It’s not very expensive because the forest has this ability to regenerate. So it’s really just to let the forest regenerate, support restoration projects, and in a few years a huge amount of forest will be regrowing. And then you are removing a lot of carbon dioxide from the atmosphere. That’s the way to go.

e360: So you have some hope that the current trends can be reversed?

Nobre: It can be reversed, but we really have to put a lot of hope in the global agribusiness markets and also the global mining companies, because there is a lot of illegal mining. About 10 percent of deforestation comes from that infrastructure and mining. But the critical thing is beef and soy. Beef is No. 1, soy is No. 2, and illegal timber is No. 3. e360: Do you think companies like agricultural multinational Cargill or McDonald’s can be subjected to this kind of consumer pressure?

Nobre: They should, and they are already making statements at Cargill because they are very threatened, very afraid of losing business. However, it’s not only about making a statement. For instance, Cargill signed a soy [deforestation] moratorium in the Amazon in 2006. Earlier this year, they signed a soy moratorium in the tropical savannas in Brazil. But, when they signed the soy moratorium in the Brazilian Amazon, they leaked new soy farms into Bolivia. So there was an explosion of soy plantations in Bolivia, and Cargill was buying that soy. So there has to be an Amazon-wide deforestation moratorium on cattle and soy. And they have four or five sister companies in the soy business.

They should be really very strict. They should have traceability to ensure zero deforestation. And another thing is productivity. Productivity of soy in the Amazon is about 2.8 tons of soy grain per hectare per year. But productivity of soy in the United States is 6.5 tons, which is more than twice that of Brazil. It’s really technology. People are not maximizing the use of technology for growing soy.

So it is up to consumers, because these companies, every time something happens, they immediately release a lot of statements. But do they work? Are they rigorous? We found out with the Brazilian meat company, JBS, the largest meat company in the world, that they signed all those things about a deforestation-free supply chain. We found out later because of corruption scandals involving JBS that it was all false. I mean they were buying meat from illegally deforested areas.

e360: Do you think the protests of the last week or two and the concern in the European Union has caught Bolsonaro’s attention?

Nobre: It absolutely has got Bolsonaro’s attention because, as I said, Bolsonaro is fully supported by Brazilian agribusiness. And for the first time, leaders of the more modern agribusinesses in Brazil have started speaking out. They never spoke before, but in the last two months they realized they would lose international support. They would risk not exporting most of their products. So they have raised their voice — a group called the Brazilian Coalition on Climate, Forests, and Agriculture, for the first time they issued a statement and delivered it to the president. They are saying, “zero deforestation.” We’re starting to see these people so concerned that they are speaking out for the first time in Brazilian history.

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