One of the hot topics at the international climate meetings in Bonn, Germany, this week is whether or not forest-rich tropical countries should get credit for protecting their forests as a way to reduce global warming. The issue is complicated, but the answer is simple: Yes.
Here's why: Tropical countries have vast amounts of carbon stored in their forests — including the trees, the soil and the peat. If that carbon ends up in the atmosphere as carbon dioxide, it will act as a heat-trapping blanket and greatly increase the growing burden of global warming — over and above problems caused by the burning of fossil fuels. It's already happening right now, with countries like Indonesia and Brazil leading the way in terms of emissions from deforestation.
When the Kyoto Protocol on global warming was drafted back in 1997 (yes, Kyoto is now 10 years old and we're still fighting about it) forest protection, or "avoided deforestation," was specifically excluded as a measurable credit in reducing emissions. That's because forests can burn down or be otherwise compromised and those emissions might go up into the atmosphere anyway.
However, evidence over the past decade has shown that forest destruction, in particular tropical deforestation, is a critical source of the heat-trapping gases that cause global warming. In fact, a paper published recently in the journal Science reported that up to 20 per cent of human-produced greenhouse gas emissions throughout the 1990s came from logging in tropical forests. What's more, if we don't find ways to slow the rate of tropical deforestation, the paper reports that we will send up as much carbon into the atmosphere in coming years as all the world's fossil fuel combustion does over an entire decade.
Questions over the permanency of tropical forests as carbon sinks are certainly legitimate. But answers to some of those questions have been found in the past 10 years. For example, an early study found that business-as-usual increases in carbon dioxide levels would raise temperatures in the Amazon to the extent that the forests would die off, releasing much of the carbon dioxide they were supposed to be storing. This study led many to believe that relying on tropical-forest conservation would be risky from a carbon-storage perspective.
But since that early paper, 10 of the 11 studies done on the issue of tropical forests for the UN-sponsored Intergovernmental Panel on Climate Change have concluded that tropical forests aren't as sensitive to temperature change as originally thought. This means that, although their ability to store carbon will gradually go down over time, we can expect tropical forests to continue to be carbon sinks right through this century.
Obviously, then, in addition to reducing greenhouse gas emissions from burning fossil fuels to combat global warming, we also need to avoid deforestation. According to the Science paper, cutting tropical deforestation in half by the middle part of this century will reduce heat-trapping emissions by 12 per cent of what will ultimately be necessary to keep our climate stable and avoid dangerous global warming.
Developing countries will be the hardest hit by global warming, as they do not have the infrastructure to deal with increasing extreme weather events, rising sea levels and other effects of a changing climate. In many developing countries, deforestation is also the greatest source of greenhouse gas emissions. As a result, it's in the best interests of these nations to protect their forests.
International delegates at the meetings in Bonn this week will decide if tropical forest protection should be included as a form of emissions reduction for the next phase of the Kyoto Protocol. Given the amount of carbon stored in our tropical forests and what's at stake, this is not really an option — it's a must.