August was another record month for global wildfire emissions, according to new satellite data. The Copernicus Atmosphere Monitoring Service of the EU found that burning forests released 1.3 gigatonnes of carbon dioxide last month, mostly in North America and Siberia. This was the highest since the organisation began measurements in 2003. After a July record of 1258.8 megatonnes the previous month, scientists are concerned that areas with dense vegetation are becoming a source rather than a sink of greenhouse gases. The increased flammability was evident across swathes of the northern hemisphere. Russia, which is home to the world’s biggest forest, was by far the worst affected as infernos in the taiga forests of Siberia pumped 970 megatonnes of carbon dioxide into the atmosphere between June and August – more than all the forests in the rest of the world put together.