Climate change in Australia is a highly contentious political issue. Temperatures in the country rose by approximately 0.7 °C between 1910 and 2004, following an increasing trend of global warming. Overnight minimum temperatures have warmed more rapidly than daytime maximum temperatures in recent years. The late-20th century warming has been largely attributed to the increased greenhouse effect. According to the Bureau of Meteorology (BOM), 80% of the land receives less than of rainfall annually and 50% has even less than . As a whole, Australia has a very low annual average rainfall of .