Although it is obvious to suspect dry regions of forests to struggle to cope with increasing temperatures and longer droughts, new studies show that climate change may have a more widely spread deadly impact than previously foreseen. The new study, published in Nature, looked at 226 species of tree from 81 spots around the globe. The research showed that 70% of tree species adapted closely to the rainfall amount of the region. This means that when short-lived, drastic climate changes affect a region, the trees will not be able to survive. Each time a tree survives a period of drought, small air bubbles form in the vascular tubes of the tree (embolisms) prohibiting the transport of water. If these droughts increase, the embolisms will make it impossible for the tree to sustain itself and it will die. Another downside of drought stress is carbon emissions. Drought-stressed trees cannot absorb C02 as effectively, adding to the greenhouse effect and further climate fluctuations. This causes a self-destructive cycle, in which loss of tree species adds to the greenhouse effect and the increasing amount of drought-stressed trees. A program that would provide funding for forest protection (REDD+, Reducing Emissions from Deforestation and forest Degradation) is being put on hold because the U.S. and China will not commit to emissions reductions. If the major polluting nations do not agree to reduce carbon emissions, other countries will not put forth money for REDD+.