A confirmed slowdown in global warming "does not invalidate climate change," the national science academies of Britain and the United States say. In a jointly published guide on the state of climate change science, the Royal Society and the National Academy of Sciences emphasized the observed slowing of warming did not "invalidate" the long-term trend of rising temperatures and climate change caused by human activity. "Despite the decadal slowdown in the rise of average surface temperature, a longer-term warming trend is still evident. Each of the last three decades was warmer than any other decade since widespread thermometer measurements were introduced in the 1850s," the academies said in the publication Climate Change Evidence and Causes. The academies' report says unequivocally the world is warming and temperatures will increase by a further 4.6 to 8 degrees Fahrenheit by the end of this century, The Guardian reported. Such warming will have significant impacts around the world, the academies said. "Global warming of just a few degrees will be associated with widespread changes in regional and local temperature and precipitation as well as with increases in some types of extreme weather events," they wrote.