The Intergovernmental Panel on Climate Change (IPCC) calculated projected temperature changes for various scenarios in 2007 and researchers at the Max Planck Institute for Meteorology in Hamburg have now gone one step further: they have developed a new model that specifies the maximum volumes of carbon dioxide that humans may emit to remain below the critical threshold for climate warming of two degrees Celsius. To do this, the scientists incorporated into their calculations data relating to the carbon cycle, namely the volume of carbon dioxide absorbed and released by the oceans and forests. The aim of the international ENSEMBLES project is to simulate future changes in the global climate and carbon dioxide emissions and thereby to obtain more reliable threshold values on this basis. (Climatic Change, July 21, 2010).

Reducing emissions of black carbon, the dark component of soot, could be the best – and perhaps only – way to save the Arctic from warmer temperatures that are melting its snow and ice, according to a study published today in the Journal of Geophysical Research. Dr. Mark Jacobson of Stanford University studied the short-term effects of reducing black carbon and other greenhouse gases, including CO2 and methane, over a 15-year period of time, with black carbon reductions appearing to be the fastest way to avoid further Arctic ice loss and warming.