endangered species | Allison Hanes

Research published in 2012 provided a better understanding of tropical deforestation’s contribution to greenhouse gas emissions. Two studies — one published in Science and the other published in Nature Climate Change, concluded that while deforestation now accounts for a lower share of global emissions relative to the late 1990s, it still represents roughly 10 percent of gross emissions. Estimates of emissions from deforestation, forest fires, and peatlands degradation remain highly contentious.

Rainforest in Sabah, Malaysian Borneo. Photo by Rhett A. Butler © Mongabay.com

Several papers published in 2012 raised disturbing questions about the health of tropical forests worldwide. In January, a review published in Nature warned that deforestation, forest degradation, and the effects of climate change are weakening the resilience of the Amazon rainforest ecosystem, potentially leading to loss of carbon storage and changes in rainfall patterns and river discharge. That warning was echoed by a December Proceedings of the National Academy of Sciences study that found the effects of the massive 2005 Amazon drought persisted longer than previously believed, raising questions about the world’s largest tropical forest to cope with the expected impacts of climate change.

Meanwhile other research came to similar conclusions about forests outside the Amazon. A paper published in July in the Journal of Geophysical Research-Biogeosciences painted a grim future for Borneo’s forests. A Nature study that assessed the specific physiological effects of drought on 226 tree species at 81 sites in different biomes around the world found that forests worldwide are at ‘equally high risk’ to die-off from drought conditions, suggesting that large swathes of the world’s forests — and the services they afford — may be approaching a tipping point.