limate change is rightly recognised as avery real and urgent global issue. Itsconsequences are already beingexperienced every day and are likely to getworse. At the Met Office we have been studying climatechange for over thirty years. As one of the world-leadersin climate change science, we provide expert evidenceon past and future climate change to governments,businesses and the public on almost a daily basis. THE FACTSOver the time that the Met Office has been studyingclimate change, research has progressed at anincredible rate; the key facts of climate change are wellknown by all:. Human activities, especially burning coal, oil andgas, have led to an increase in greenhouse gases inthe atmosphere. These enhance the naturalgreenhouse effect and cause the Earth to warm.. The main greenhouse gas responsible for recent climate change is carbon dioxide (CO2). Atthe same time that our emissions have been growing,the ability of the natural world to take up CO2 has been declining through actions such asdeforestation. . As a result, over the past century there has been arapid rise in CO2 levels to values not experienced bythe Earth for at least 800,000 years, and with that,an underlying increase in average temperatureswhich is continuing. Globally, the ten hottest years onrecord have all been since 1997.The overwhelming majority of climate scientists allagree on the fundamentals of climate change -thatclimate change is happening and increasedgreenhouse gases from human activities are causing it.Despite this overwhelming consensus, the last 12months have been some of the most challenging forthe climate change science community. From stolenemails, the perceived lack of a deal at Copenhagen, to the uncovering of errors in the IPCC reports, these events have all taken their toll on the credibilityof our science. However, despite the furore created by these events,the body of scientific evidence showing how ourclimate is changing continues to grow. THE EVIDENCEUnmistakable evidence of our warming world wasrevealed in the most recent "State of the Climate"report, issued by US National Oceanic andAtmospheric Administration (NOAA). The report,drawing on data from key climate indicators compiledby the Met Office Hadley Centre, showed how land and ocean temperatures and ocean heat content are all increasing.The evidence, however, is not only seen in globaltemperatures. Further Met Office research hasrevealed shifts in rainfall patterns, changes inhumidity, reductions in the extent of sea ice, snowcover and glaciers, as well as changes in the salinity ofthe oceans. All these trends follow the pattern of expected climate change and bear the fingerprint of human influence. This compelling evidence draws us tothe conclusion that our climate isunequivocally changing, and man-made greenhouseAN UNCERTAIN FUTURE?084GLOBAL VOICESCPROFESSOR JULIA SLINGO OBE, CHIEF SCIENTIST, MET OFFICE

GLOBAL VOICES085gas emissions are very likely to be the cause.MEETING NEW CHALLENGESAlthough this evidence supports the case for awarming world globally, the challenges we facewill be felt at a local level and so thequestions being asked by policymakersare changing. How exactly will theclimate change from place to place? Transport infrastructure, hospitaladmissions, energy consumption andmany other weather-critical societalneeds are impacted, not by globalaverage temperatures, but by the dailyand seasonal swings in temperature locally,and more critically by temperature extremes.In response to this, the Met Office has led aninternational initiative to create a new global surfacetemperature dataset at daily or even shortertimescales, to tell us about how our local climate ischanging in ways that affect us directly. Similarly, many of the most profound impacts ofclimate change will be felt through changes in rainfall- too much, too little, at the wrong time, in the wrongplace. This means that our models must be able tocapture the weather systems which produce thatrainfall, and we are working hard to develop models atmuch higher resolution, closer to those we use forweather forecasting. Such models should be able toanswer key questions around the impacts of climatechange, such as whether the Indian monsoon will failor whether spells of extreme drought or flood, with alltheir related consequences, will change in frequencyor intensity.?