English: Tropical deforestation should be our primary concern

The world loses almost six million hectares of forest each year to deforestation. That’s like losing an area the size of Portugal every two years. 95% of this occurs in the tropics. The breakdown of deforestation by region is shown in the chart. 59% occurs in Latin America, with a further 28% from Southeast Asia. In a related article we look in much more detail at what agricultural products, and which countries are driving this.

As we saw previously, this deforestation accounts for around one-quarter of global forest loss. 27% of forest loss results from ‘commodity-driven deforestation’ – cutting down forests to grow crops such as soy, palm oil, cocoa, to raise livestock on pasture, and mining operations. Urbanization, the other driver of deforestation accounts for just 0.6%. It’s the foods and products we buy, not where we live, that has the biggest impact on global land use.

It might seem odd to argue that we should focus our efforts on tackling this quarter of forest loss (rather than the other 73%). But there is good reason to make this our primary concern.

Philipp Curtis and colleagues make this point clear. At their Global Forest Watch platform they were already presenting maps of forest loss across the world. But they wanted to contribute to a more informed discussion about where to focus forest conservation efforts by understanding why forests were being lost. To quote them, they wanted to prevent “a common misperception that any tree cover loss shown on the map represents deforestation”. And to “identify where deforestation is occurring; perhaps as important, show where forest loss is not deforestation”.

Why should we care most about tropical deforestation? There is a geographical argument (why the tropics?) and an argument for why deforestation is worse than degradation.

Tropical forests are home to some of the richest and most diverse ecosystems on the planet. Over half of the world’s species reside in tropical forests. Endemic species are those which only naturally occur in a single country. Whether we look at the distribution of endemic mammal species, bird species, or amphibian species, the map is the same: subtropical countries are packed with unique wildlife. Habitat loss is the leading driver of global biodiversity loss. When we cut down rainforests we are destroying the habitats of many unique species, and reshaping these ecosystems permanently. Tropical forests are also large carbon sinks, and can store a lot of carbon per unit area.

Deforestation also results in larger losses of biodiversity and carbon relative to degradation. Degradation drivers, including logging and especially wildfires can definitely have major impacts on forest health: animal populations decline, trees can die, and CO2 is emitted. But the magnitude of these impacts are often less than the complete conversion of forest. They are smaller, and more temporary. When deforestation happens, almost all of the carbon stored in the trees and vegetation – called the ‘aboveground carbon loss’ – is lost. Estimates vary, but on average only 10-20% of carbon is lost during logging, and 10-30% from fires. In a study of logging practices in the Amazon and Congo, forests retained 76% of their carbon stocks shortly after logging.31 Logged forests recover their carbon over time, as long as the land is not converted to other uses (which is what happens in the case of deforestation).

Deforestation tends to occur on forests that have been around for centuries, if not millennia. Cutting them down disrupts or destroys established, species-rich ecosystems. The biodiversity of managed tree plantations which are periodically cut, regrown, cut again, then regrown is not the same.

That is why we should be focusing on tropical deforestation. Since agriculture is responsible for 60 to 80% of it, what we eat, where it’s sourced from, and how it is produced is our strongest lever to bring deforestation to an end.