The world needs to prepare itself for a rapid increase in the speed of climate change , scientists have warned . US researchers claim that the fast onset of global warming is set to alter the way people live , even over short time scales . This is according to new evidence which suggests the rate at which temperatures are rising in the northern hemisphere could be 0.25°C per decade by 2020 - a level not seen for at least 1,000 years . New evidence suggests the rate at which temperatures are rising in the northern hemisphere could be 0.25°C per decade by 2020 - a level not seen for at least 1,000 years . The Arctic ( purple ) will be have the most dramatic increase , followed by North America ( brown ) , Europe ( black ) and Asia ( red ) The analysis , based on a combination of data from more than two dozen climate simulation models from around the world , looked at the rate of change in 40-year long time spans . 'We focused on changes over 40-year periods , which is similar to the lifetime of houses and human-built infrastructure such as buildings and roads , ' said lead scientist Dr Steve Smith , from the Pacific Northwest National Laboratory in Washington . 'In the near term , we 're going to have to adapt to these changes . ' Overall , the world is getting warmer due to increasing greenhouse gas emissions that trap the sun 's heat . But , given natural climate variability over short times scales , the likely effect of global warming over humanly relevant periods such as the length of a person 's life is not so well understood . 'We focused on changes over 40-year periods , which is similar to the lifetime of houses and human-built infrastructure , ' said lead scientist Dr Steve Smith , from the Pacific Northwest National Laboratory in Washington . The graph shows the predicted changes under different scenarios of climate change . The new study started off by calculating how fast temperatures changed between 1850 and 1930 , a period when the amount of fossil fuel gases collecting in the atmosphere was low . This was compared with temperature data for the past 2,000 years obtained by studying tree rings , corals and ice cores and predicted 40-year rates of change between 1971 and 2020 . Over the 900 years preceding the 20th century , 40-year warming trends rarely showed an average rate much higher than 0.1°C per decade , the study found . But by 2020 the rate was expected to have risen to an average of 0.25°C per decade , give or take 0.05°C . Different scenarios of future emissions showed that even at the lower end of greenhouse gas generation climate change picked up speed in the next 40 years . Dr Smith added : 'In these climate model simulations , the world is just now starting to enter into a new place , where rates of temperature change are consistently larger than historical values over 40-year time spans . 'We need to better understand what the effects of this will be and how to prepare for them . ' The findings are published in the journal Nature Climate Change . The US National Oceanic and Atmosopheric Administration has detected warmer than average water temperatures around the equator of the Pacific Ocean ( shown above ) which indicates the arrival of El Niño . The world is finally in the grip of a long-awaited El Niño event that could alter global weather patterns - but the phenomenon is far weaker than expected . El Niño is caused by a shift in the distribution of warm water in the Pacific Ocean around the equator . Scientists have announced that sea surface water temperatures have been warmer than average in the western and central Pacific Ocean and have started to alter wind patterns . The US National Oceanic and Atmospheric Administration now predicts that there is now a 50 to 60 per cent chance El Niño will continue through the summer . However , they say that the El Niño conditions are currently 'extremely weak ' and come at a time of the year when the influence of El Niño on weather patterns usually declines . The NOAA said that it was unlikely the phenomenon would bring enough rain this spring to break the three-year record-breaking drought that is currently affecting California . Some meteorologists , however , have warned this El Niño could combine with another slow movement of water in the Pacific Ocean called the Pacific Decadal Osciallation ( PDO ) . The PDO reached record levels in December last year and January this year , and should it stay strong , it may combine with El Niño to increase global temperatures .
Rate in the northern hemisphere could be 0.25°C per decade by the 900 years . Figure is more than double 2020 preceding the 20th century . The warning was issued by the Pacific Northwest National Laboratory . They say we need to better understand what the effects of this will be .