TICK TOCK THE CLIMATE CLOCK PART TWENTY

We’re at Part Twenty of Tick Tock the Climate Clock.  That’s apt, because a recent study reported in Science Magazine by Thomas Lovejoy and Carlos Nobre warns that if deforestation in the Amazon rainforest reaches 20-25%, that is a tipping point beyond which the forest could begin to self-destruct in a process called dieback.  Here is a link to the reported study:  https://advances.sciencemag.org/content/4/2/eaat234   If dieback happens as Lovejoy and Nobre fear, then half or more of the rainforest could transform itself into savanna, the Amazon ecosystem as a whole could switch from being a net absorber of CO2 to a net emitter of carbon, and rainfall and weather patterns on the continent and beyond could change. 

But before I start running around with my hair on fire because the Amazon is in flames, I want to know if dieback is actually a realistic possibility or climate change hype.  According to the latest issue of the MIT Technology Review at
https://www.technologyreview.com/s/614222/we-arent-terrified-enough-about-losing-the-amazon/

… scientists can’t exactly say. Some models show the phenomenon, some don't. Where some researchers detect a tipping point in the data—which technically means it would continue on its own even if the forces that first drove it fade away—others see merely progressive deterioration that could be halted. Still other studies have found such a phenomenon would most likely convert rainforest into seasonal forest, rather than savannah.

So what should we do in the face of this kind of scientific uncertainty? Like other climate tipping points, which are unpredictable and essentially irreversible once reached, we should err on the side of caution.

“Even if it’s a remote possibility, we cannot afford to ignore it,” says Jonathan Foley, executive director of Project Drawdown, a research group focused on decarbonization. “It would be absolutely catastrophic to the Earth’s carbon cycle, water cycle, climate, and biodiversity—not to mention the people who live there.” 

OK, so let's err on the side of caution.  The next thing I want to know is how close we are to the 20-25% tipping point.  According to Lovejoy, quoted in the New York Times, https://www.nytimes.com/2019/08/30/world/americas/amazon-rainforest-fires-climate.html?smid=nytcore-ios-share  

“It’s close.  It’s really close.”

That’s too vague.  I need to know how close is “really close.”  In an email sent to MIT Technology Review, Lovejoy was more precise.  He calculates that 17% of the Amazon rainforest has already been lost to deforestation in the last 50 years.   Based on my online research, National Geographic and the World Wildlife Federation agree.  But how did researchers come up with that number?  How was the 17% calculated, and is it accurate?

The answer is:  I’m not sure.  As best as I can tell, the calculations are based on satellite imagery like the one above and reporting on deforestation by the nine countries containing the Amazon rainforest.  That raises two questions.  First, what is the Amazon rainforest, and second, what is reported as deforestation?

Taking the definition of the Amazon first, is there agreement on the boundaries and land area of the rainforest?  Is everybody measuring the same thing?  You would think that would have a fairly straightforward answer, but it doesn’t.  Some sources put the area of the rainforest at 5.5 Million square kilometers; others say it's 6.73 Million square kilometers.  That’s a considerable difference—almost 20%.  That could have a tangible effect on how much rainforest has already been lost and on the 20-25% tipping point.

Second, what is deforestation?  Sounds simple enough:  Once there were trees; now there aren’t.  But again, it’s not straightforward at all.  For example, the Global Land Analysis and Discovery Lab at the University of Maryland looked at deforestation between 2010 and 2017 (see the chart below).  By its calculations, the Amazon as a whole (however they measured it) lost 21.3% of its trees in that period.  (Yikes!  That’s into tipping point range!)  GLADL breaks this total down for each of the nine countries that contain the Amazon rainforest.  According to GLADL, Brazil, which accounts for 60% of the rainforest, has lost 5.5% of its forest cover between 2010 and 2017.  But the Brazilian government’s official estimate puts the loss to deforestation during that same period at only 1%.

How can that be?  Well, it depends on how you define deforestation.  The Brazilian estimate of deforestation in the Brazilian Amazon (however they measured it) in 2010 was 18.1%.  By 2017, that percentage increased to 19.1%, for a difference of 1%.  Who's right?  I’m not sure, but here is a clue to the discrepancy.  Brazil’s figures do not include rainforest cover lost to burning.  (What?!)  That number is buried in another data point (see the table "Annual deforestation and area affected by fires in the Amazon" in the link below). 

As indicated in the table, when the estimates of forest cover were first compiled in 1970 by the Brazilian National Institute of Space Research and the United Nations Food and Agriculture Organization, there were 4,100,000 square kilometers of forest cover remaining in the Brazilian Amazon.  Between 2010 and 2017, some 567,626 square kilometers of “areas” were burned, some of it repeatedly and some of it rainforest.   We just don’t know how much of those 567,626 square kilometers were rainforest and how much were previously cleared areas, but that could explain the difference between a 5.5% loss and a 1% loss.  Here is the link to my source and the table: https://rainforests.mongabay.com/amazon/deforestation_calculations.html

So it’s useful to look beyond the climate crisis headlines before freaking out.  It seems to me the numbers that go into the 17% deforestation calculation might be pretty soft; one might even say squishy.  Still, I wouldn’t get overly comfortable about that.  Any further loss of rainforest in the Amazon is a negative and efforts to reverse that trend and the damage already caused should be massive and sustained. 

Which brings us to reforestation and the happy part of this post.   

Sebastião Salgado

It’s not clear that the Amazon will tip into dieback and, more importantly, it doesn’t have to.  Neither deforestation nor the disruption of rainfall and change in weather patterns it causes is inevitable or irreversible.  A wonderful biographical documentary film directed by Wim Wenders and Juliano Ribeiro Salgado called Salt of the Earth proves it.  The film portrays the works of Juliano Ribeiro Salgado's father, the Brazilian photographer Sebastião Salgado and how he reclaimed 1,750 acres in Brazil’s Atlantic Forest from desertification.  If you haven’t seen it, you should, and here’s a link to the trailer:  https://www.google.com/search?client=firefox-b-d&channel=crow&q=Salgado+Salt+of+the+Earth

Salgado is a famous photojournalist who returned to his family’s former farm in Minas Gerais in Brazil’s Atlantic Forest after years of documenting conflict areas and human suffering around the world.  Salgado had left his home as a young man on his way to boarding school.  That way had been paved (practically literally) by his father’s clear cutting of almost all the trees on the farm in order to raise cattle to finance tuition for his children.

When Salgado returned as an adult in 1998, the land was dead, the creek he had played in as a child had dried up, and all the wildlife had disappeared.  Determined to find peace and reconciliation in his own life and to restore the paradise of his youth, Salgado embarked with his wife on an ambitious 20-year effort to replant more than 2 Million trees and return the desiccated landscape to life.  It was tough going at the outset, but after ten years, even the creek returned!

The land is now a Private National Heritage Reserve managed by a private environmental foundation called Instituto Terra.  It is home to 293 species of trees, 172 species of birds, 33 species of mammals, and 15 species of reptiles and amphibians—many of which are endangered.  An article in My Modern Met reports the broader climate results:

As expected, this rejuvenation has also had a huge impact on the ecosystem and climate. On top of reintroducing plants and animals to the area, the project has rejuvenated several once dried-up springs in the drought-prone area, and has even positively affected local temperatures.

Ultimately—and perhaps most unexpectedly—this major feat has saved more than the local landscape. “All the insects and birds and fish returned,” Salgado shares, “and, thanks to this increase of the trees, I, too, was reborn—this was the most important moment.”

If you’d like to read more about Salgado and his hugely successful, herculean environmental project, I recommend this article from the Smithsonian Magazine: https://www.smithsonianmag.com/arts-culture/sebastiao-salgado-forest-trees-180956620/

So if it's not too late, good things are still possible for the Amazon and its people.  Let’s all wish for an Amazon that hasn’t tipped into self-perpetuating destruction, an end to deforestation that destroys CO2 storage, a discontinuation of burns that release carbon into the atmosphere, and the replanting of billions of trees in the rainforest ecosystem.  It’s a big wish list, and it's a challenging wish list, but it’s not an impossible wish list.  And the rewards would be huge.  The Amazon can either look like Instituto Terra or Terra Incognita.

Keep it real!

Marilyn