Bonn study shows: Since 1880 climate gases have caused just under half of global warming
In the last 120 years the average global temperature has risen by 0.7 degrees. Over the same period the carbon dioxide concentration in the atmosphere increased from 0.28 to 0.37 per cent. Carbon dioxide is one of the so-called 'greenhouse gases'; methane, which is produced as part of the process of cattle-rearing, for example, is also a greenhouse gas. Its concentration in the atmosphere has risen since 1750 two and a half times. Climatologists regard it as likely that man-made greenhouse gases have contributed to global warming.