Conserving tropical forests could get us halfway to solving global warming

Brett Byers is heavy-hitter in rainforest conservation: a venture capitalist who serves on the board of Rainforest Trust and who helped initiate the Million Acre Pledge.  He is also co-author of a recent article asserting that conserving tropical forests could take us halfway toward a solution for global warming.  Here he tells us about this remarkable analysis and its planet-shaking implications:

As nations meet in Paris this week to discuss and debate climate change, I would urge that we all pay keen attention to forests -- especially tropical forests -- as a vital bridge to a post-fossil-fuel world.

At first blush, tropical forests might not seem like a big enough bullet to attack global warming.  For instance, the net loss of tropical forests and peat-lands is estimated to cause 12 to 15 percent of all human-caused carbon-dioxide emissions. 

For this reason, many look to reducing fossil-fuel use as the main solution to global warming -- and there's no doubt that this is crucial.

But in a recent Commentary in Nature Climate Change, my coauthors and I show how conserving and restoring tropical forests could take us up to halfway toward solving global warming over the next 50 years.

Part 1: Add forest regrowth to halting forest loss

The first part of our strategy focuses on adding forest regeneration -- especially for the vast areas of tropical forests that have been degraded by industrial selective logging -- to a halt in forest destruction.

Rainforest logging in Borneo (photo by Rhett Butler / Mongabay.com)

Worldwide, some 400 million hectares of tropical forest -- an area nearly a dozen times the size of Germany -- are currently in some form of logging estate.  Selective logging typically results in the loss of 25-50 percent of a forest's carbon storage, as many trees are harvested or killed during initial or repeated logging cycles.

Protecting logged forests -- many of which are currently being cleared -- and allowing them to regenerate would absorb billions of tons of carbon dioxide over the next several decades.  Several analyses conclude that this regrowth, combined with a halt to further forest loss, could offset about 30 percent of all human-caused carbon-dioxide emissions.

Thirty percent of all emissions is a very big number, and it takes us a good part of the way toward a global warming solution.

Part 2: Faster benefits from forests

In addition, protecting and regenerating forests is a relatively quick-fire way to reduce carbon emissions.  And that's important.  The benefits would accrue faster and thereby have a large near-term benefit for limiting global warming -- compared to alternatives such as devising and implementing alternatives to fossil fuels.

Hence, when it comes to slowing global warming, tropical forests are the low-hanging fruit.

Forest destruction in the Congo Basin (photo by William Laurance)

According to our calculations, over the next 50 years, the one-two punch of promptly stopping tropical deforestation while protecting and regenerating degraded tropical forests could produce up to half of the reduction in carbon emissions that we so direly need. 

Thus, in the crucial coming decades, these steps could take us up to halfway towards a solution to global warming.

Reality or pie in the sky?

Some might question this kind of thinking, but these are hard numbers, not fantasy. 

Other forest and land-use changes, in addition to tropical forest conservation, could provide substantial benefits in the fight against global warming. 

But tropical forests are among the largest forests left on the planet, and the fact that they grow year-round means they can absorb a lot of carbon quickly.

There are lots of good reasons to conserve tropical forests -- for their stunning biodiversity, their role in protecting water supplies and reducing flooding, and their manifold practical uses for humanity, among others.

For lots of good reasons, conserving tropical forests is a no-brainer (photo by William Laurance)

But the importance of tropical forests to the global carbon cycle simply can't be overstated. 

As the world debates potential solutions to global warming in Paris this week, conserving tropical forests should be right at the top of our list.