Cutting edge scientific projections, launched today, provide the most detailed picture to date of the threat facing Britain from soaring summer temperatures and sudden flash floods together with an increased risk of coastal erosion from rising sea levels.

The UK Climate Projections, announced by Environment Secretary Hilary Benn, were compiled for Defra by the Met Office Hadley Centre using  a series of climate models and processed by one of Britain’s most powerful super computers. They provide new information about the UK’s future climate and are an important step forward in understanding the complexities of climate change.

Across the UK, the Projections show a range of temperature increases and rainfall changes up until the end of the century.  Based on three greenhouse gas emissions pathways – high, medium and low – they present a range of different probabilities for climate variables. Broadly speaking we are currently on the medium pathway.

On the medium emissions pathway summer temperature is projected to rise between 2 and 6 degrees C by the 2080s. Our central estimate is a rise of 4 degrees within our children’s lifetime unless we reach a global deal to reduce greenhouse gas emissions.

At the outside of the projections, temperatures could be even higher -  by up to 11 degrees C - if a high emissions scenario is reached. This would mean peak summer temperatures in London of over 40 degrees on some days.

At the same time there would be a dramatic effect on rainfall patterns across the UK. Under the medium emissions scenario, average summer rainfall is the south east – already considered ‘water-stressed’– is projected to decrease by 22 percent while winter rainfall in the north west is anticipated to increase by 16 percent which could lead to increased flooding.

Together these findings are sobering.  Extreme weather events will be more likely. There will be an increase in water shortages, heat waves and floods. All of these could have an impact on our quality of life, the economy and the natural environment.

However the projections also show that we have a choice about the severity of change we face in the future. The message is clear that we need a strong global deal at Copenhagen in December to restrict global temperature rises to reduce emissions and adopt an emissions pathway that is even lower than that currently modelled in the UK Climate Projections. However the projections show that although action to reduce greenhouse gas emissions is critical to avoid the most dangerous effects of climate change, past emissions mean that some changes are now inevitable up to the 2040s.

Environment Secretary, Hilary Benn said:

‘There is no doubt about it – climate change is one of the biggest challenges facing the world today. Never before have we such strong scientific evidence that shows that we not only need to tackle the causes of climate change but that we must also deal with the consequences. Climate change is already happening – the story so far already shows that the hottest ten years on record have been since 1990. What we now have is the chance to decide what the future holds and the extent to which we need to adapt the way we live and work.’

Energy and Climate Change Secretary, Ed Miliband said:

“The science is pushing us harder than ever towards an ambitious global deal in Copenhagen this December.  These projections add to the overwhelming body of scientific evidence that says mankind must cut carbon emissions now to prevent a future of extreme weather patterns which could endanger plants, animals and sea life and affect the way we live and work.

“Now is the time to act. The UK has set an example to the world by committing to an 80% target on emissions reductions by 2050. We are well placed to achieve this and are determined to seize the opportunities presented by the shift to low carbon. We need all other countries to be part of a global deal on climate change.”

However it is also clear that reducing emissions is not enough: even at a two degree increase we will need to adapt the way we live and work. For example the summer heatwave of 2003 saw average daily temperatures of 2 degrees above the UK average and caused over 35,000 deaths across Northern Europe. As early as the 2040s these temperatures could be the norm, not the exception.

Hilary Benn said:

‘The stark message from the projections is that we must cut global emissions now to prevent Britain from baking every summer but that we must also prepare for a changing future.

‘The Projections are the keystone of our plan to tackle climate change and are the best tool yet to help us plan and prepare to ensure that we have a resilient infrastructure to cope – whether it’s the design of school buildings or protection of new power plants, maintaining the supply of drinking water, adjusting farming methods for drier summers or understanding how our homes and businesses will have to adapt.’

Note to Editors

1. The Projections are based on three global emissions scenarios outlined by the Intergovernmental Panel on Climate Change – high, based on a fossil fuel reliant economy; medium, based on a mix of fossil fuel reliance and new lower carbon technologies; and low, based on increased use of new technologies. The UK’s Committee on Climate Change suggests that the world is currently broadly following a medium emissions scenario.
   
   
2. The Climate Projections 2009 were developed using Met Office climate modelling in conjunction with the UK Climate Impacts Programme. They have been developed using the Met Office climate change model combined with 12 global models to provide a range of probabilistic outcomes based on the strength of evidence – for example a minimum temperature increase below which we think is unlikely, a maximum, above which is unlikely and a central estimate.
   
   
3. The 2009 Projections are presented for each UK region at a 25k resolution to take into account local topography for more detailed simulations across the country. The probabilistic approach allows users to adopt a risk-based approach to planning – for example users may choose to use the worst case scenario (eg high emissions scenario, projected maximum temperature increase) for planning decisions where the impact is potentially high such as the future of the Thames Barrier.
   
   
4. The Projections build on the data published in 2002 which provided one best estimate for climate changes rather than a probabilistic range.
   
   
5. All figures quoted in the press release are the central estimate for the medium emissions scenario for the 2080s. The projections are presented as ranges for each of the emissions scenarios from 10% to 90% probabilities, with 10% unlikely to be less than and 90% unlikely to be more than. The Projections use a baseline of 1961-90 and provide information on temperature rise, rainfall, sea level rise, snowfall, humidity, radiation and cloud level for all three emissions scenarios in 30 year time periods. The Projections can be found at the Defra website.