Speaker 1: Welcome to brain Stuff. Production of I Heart Radio, Hey
Speaker 1: brain Stuff Lauren vog obamb here. In recent years, climate
Speaker 1: change has loomed like a dark specter over the globe,
Speaker 1: contributing to everything from gentrification in Miami is high income
Speaker 1: coastal dwellers seek new residents fur their inland away from flooding,
Speaker 1: two refugees fleeing drought and crop shortages in Guatemala. But
Speaker 1: the urgency around the issue reached new heights in the
Speaker 1: United Nations. Intergovernmental Panel on Climate Change or IPCC stated
Speaker 1: that rapid, quote, far reaching and unprecedented changes in all
Speaker 1: aspects of society would be needed in order to drop
Speaker 1: carbon dioxide levels by and prevent catastrophic global warming. Scientists
Speaker 1: have indeed proposed drastic measures, just not the way that
Speaker 1: you might think. In the same i p c C report,
Speaker 1: the u N suggested that adding two point five billion
Speaker 1: acres that's one billion hectares of forest to the world
Speaker 1: could help limit global warming in future decades to just
Speaker 1: two and seven degrees fahrenheit that's one point five degrees celsius,
Speaker 1: which would stave off some of the worst effects of
Speaker 1: climate change. And now the U N might just have
Speaker 1: the data to back up their proposal. In another study
Speaker 1: unveiled in July of twenty nineteen and the publication Science,
Speaker 1: a group of researchers associated with the Crowther Lab in
Speaker 1: Switzerland found that global tree restoration to the tune of
Speaker 1: nine hundred million acres that's point nine billion hectares of
Speaker 1: canopy cover, an area that's approximately the size of the
Speaker 1: United States is quote our most effective climate change solution
Speaker 1: to date. That would require upwards of half a trillion trees.
Speaker 1: These trees would store two hundred and five billion tons
Speaker 1: of carbon, or roughly two thirds of the carbon that's
Speaker 1: been omitted by we humans since the Industrial Revolution. Some
Speaker 1: news reports said that this much forest restoration is the
Speaker 1: equivalent of roughly one trillion trees, but that statistick is
Speaker 1: from an estimate in a report from but we spoke
Speaker 1: with the current studies lead author Jean Frascois Bastin via email.
Speaker 1: He said the idea was to estimate what tree cover
Speaker 1: could be expected when you removed the human factor, i e.
Speaker 1: What specific types of forest would naturally occur in the
Speaker 1: absence of other development and where. The team used the
Speaker 1: form of artificial intelligence known as machine learning to build
Speaker 1: quote a model to link tree cover with climate, soil
Speaker 1: and topography based on seventy eight thousand observations of tree
Speaker 1: cover in protected areas. The researchers then projected the data
Speaker 1: further to estimate the potential total tree cover of the
Speaker 1: whole planet if human civilization didn't exist. But of course
Speaker 1: humans do exist, so the team then excluded land currently
Speaker 1: being used for urban settlements, crop lands, and existing forests,
Speaker 1: which yielded the total amount of land available for restoration.
Speaker 1: The study offers a map showing how much tree coverage
Speaker 1: different parts of the globe might support, the top three
Speaker 1: areas being Russia, Canada, and the United States. The studies
Speaker 1: timing a lines of current global efforts around ecological rest ration.
Speaker 1: A one example is the Trillion Trees Vision, which seeks
Speaker 1: to restore one trillion trees by fifty Another is the
Speaker 1: Bone Challenge, which is a partnership between the Government of
Speaker 1: Germany and the u n's International Union for Conservation of
Speaker 1: Nature that aims to restore three seventy one million acres
Speaker 1: of deep forested land by which is about of the
Speaker 1: current studies recommendation. You might be thinking, well, that sounds
Speaker 1: pretty easy. Let's all roll up our sleeves and save
Speaker 1: the planet by planting one tree at a time, right,
Speaker 1: But some experts say the situation is actually a little
Speaker 1: more complicated than that rosy picture, especially if most nations
Speaker 1: don't chip into help. Although by fifty eight nations had
Speaker 1: banded together to commit an acreage that would exceed the
Speaker 1: BONB Challenge goal, most of the restoration work to date
Speaker 1: has been done by only a few countries. We also
Speaker 1: spoke with Jim Hallett, chair of the Board of Directors
Speaker 1: for the Society of Ecological Restoration. He cited major challenges
Speaker 1: to implementing restoration on such a global scale, quote including financing, governance,
Speaker 1: land tenure and ownership, and capacity to do the work.
Speaker 1: There's ample evidence that in some contexts, if the benefits
Speaker 1: of restoration are not equally shared, the project will fail.
Speaker 1: So incentive programs have to be carefully developed, and restorational
Speaker 1: loan will likely not be enough. It takes time, after
Speaker 1: all to implement such a big restoration projects, and also
Speaker 1: for these trees to store carbon, and how it stresses
Speaker 1: that we have to not just restore previously forested lands,
Speaker 1: but preserve what we've currently got. Other scientists question not
Speaker 1: only the practicality of the studies claims, but also the
Speaker 1: studies very methodology. But we spoke with Ica Liling, climate
Speaker 1: change researcher and professor of horticultural sciences at the University
Speaker 1: of Bonne. He pointed out that some of the areas
Speaker 1: marked for restoration couldn't support more trees than they already do.
Speaker 1: Some of them are in permafrost regions for example. Also
Speaker 1: quote the methodology implicitly, probably not on purpose, implies that
Speaker 1: carbon stock is portional to canopy cover i e. Ecosystems
Speaker 1: without trees contain no carbon. This is clearly false and
Speaker 1: strongly inflates the global estimate of restoration. Young Barner, Leedling's
Speaker 1: colleague and a professor for economics of sustainable land use
Speaker 1: at the University of Bonne, is similarly skeptical. Barner says
Speaker 1: that some of the areas being proposed for restoration under
Speaker 1: the current study are already in use for other purposes.
Speaker 1: Barner considers the study to be a quote interesting academic exercise,
Speaker 1: but as a climate change mitigation strategy proposal, and it
Speaker 1: is being advertised as such, it sends a misleading signal
Speaker 1: to the international climate policy debate, but don't fret. Both
Speaker 1: Bustine and Hallett emphasize that the u N has declared
Speaker 1: thirty the Decade on Ecosystem restoration, which could spur nations
Speaker 1: to act quickly, and some countries are already tackling the
Speaker 1: initiative head on. And according to Hallett, forest restoration boasts
Speaker 1: far more perks than just impacting climate change, including maintaining
Speaker 1: or even increasing bio diversity and preserving the ecosystem that
Speaker 1: we humans rely upon for our food and water. But
Speaker 1: even the studies authors acknowledge that it's going to take
Speaker 1: a lot of goodwill to make this grand vision of reality.
Speaker 1: Bastine said, what we need is a universal action. International
Speaker 1: agencies and geo's governments all citizens anyone can be involved.
Speaker 1: Local communities and small organizations may be especially effective. While
Speaker 1: they do not have the same reach as national agencies,
Speaker 1: they have the benefit of knowing what works best in
Speaker 1: their own backyards. Today's episode was written by Terry our
Speaker 1: Lagata and produced by Tyler Clang. The brain Stuff is
Speaker 1: a production of iHeart Radio's How Stuff Works. For more
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