In good news for the United States’ overall carbon contribution, and bad news for countries hoping to cash in on carbon-saving biofuels, an Australian study recently found that many forests contain three times as much carbon as the UN’s Intergovernmental Panel on Climate Change had believed. 

While the IPCC figures estimate carbon storage for forest based on trees above six feet and a canopy coverage of a scant ten percent, the Australian study found that older growth forests with trees in excess of 30 feet, and canopy coverages of 60 percent hold more carbon—up to three times as much. The study also found that even well-managed, selectively logged forests were up to 40 percent less efficient carbon sinks than their untouched counterparts. 

By eliminating large plants that literally suck carbon out of the atmosphere, deforestation contributes some 18% of yearly global warming emissions. In the US, continued forest growth actually decreases the carbon footprint by roughly 1.5 tons of carbon dioxide per capita. But in many developing nations, deforestation emissions account for the vast majority of heat-trapping gas emissions. 

This could be especially bad news for biofuel backers, as forests cleared to plant fuel crops may limit the carbon-friendliness of biofuel plantations.