© Crown copyright Met Office Evidence in Science and Policy Scientific evidence Vicky Pope

© Crown copyright Met Office Growing evidence of man-made climate change Importance of natural variability Practical information for decision making Dealing with complexity and uncertainty Scientific evidence

© Crown copyright Met Office Growing evidence of man-made change

© Crown copyright Met Office Scientific evidence The average temperature of the Earth is 15 ºC. Without the blanket of greenhouse gases it would be –18 ºC. CO 2 has risen by 107ppm (38%) from pre-industrial levels of 280ppm. Two thirds of the increase is in the last 50 years. CO 2 is 30% higher than at any time over at least the last 800,000 years. Global temperatures have increased decade on decade since the mid 20th century, consistent with the basic physics. The water vapour feedback enhances the warming due to man-made greenhouse gases

© Crown copyright Met Office Evidence of temperature rise: Independent datasets

© Crown copyright Met Office Practical information for decision making

© Crown copyright Met Office Central estimate from UKCP models Upper limit of "high++“ model Probability forecasts of coastal flood risk allow for a balanced approach to decision making Change in extreme sea level of 50 year storm

© Crown copyright Met Office ─ Observations █ Model Individual projections from 2009 ─ ─ ─ Global average temperature forecast for the next decade Likely that half the years from 2010 will be warmer than 1998

© Crown copyright Met Office The impact of a global temperature rise of 4 ºC Change in temperature from pre-industrial climate Current City population 3-10 million million Melting ice Ocean Acidification Rainforest loss Reduced crops Forest fire Increased drought Stronger tropical storms Methane release More heatwaves