Climate Change Risk Assessment

Monday 30th Jan 2012 by theWeather Club

Image: Andrew Smith

The Department for Environment, Food and Rural Affairs (Defra) has produced the Climate Change Risk Assessment, a 2,000-page document that forms part of the government's strategy for coping with global warming and will be used to prepare the government’s national adaptation plan, due to be published next. The Defra report lists 700 impacts, including flood risk for 3.6 million people, water shortages, soil erosion and wildlife disruption.

Climate change this century poses both risks and opportunities, according to the first comprehensive government assessment of its type. The report warns that flooding, heatwaves and water shortages could become more likely. But benefits could include new shipping lanes through the Arctic, fewer cold-related deaths in winter and higher crop yields. Flooding is the greatest threat to the UK posed by climate change, with up to 3.6 million people at risk by the middle of the century.

One aim of the work is to raise awareness of the scale of possible changes and to encourage key organisations to plan ahead. The research was carried out over the past three years and involved studying the possible impacts in 11 key areas including agriculture, flooding and transport.

All the scenarios rely on computer models of the future climate and therefore inherently involve uncertainties. The assessments rely on multiple scenarios based on computer modelling of the future climate. The relatively small size of the UK means that modelling at a regional and local level remains a serious challenge. The report is designed to provide a "baseline" for the assessment so that it is easier to demonstrate the risks unless action is taken.

The four most immediate "high consequence" risks all concerned flooding, with the expectation that in 10 years or so there will be increased flood damage to homes, with knock-on effects on insurance premiums and mental health. The report also highlighted hotter summers leading to between 580-5900 deaths above the average per year by the 2050s and water shortages in the north, south and east of England, especially the Thames Valley area by the 2080s.

Lord John Krebs, chairman of the adaptation committee of the independent advisory group Committee on Climate Change, said that without planning and investment to deal with the threats the UK would "sleepwalk into disaster". The benefits of climate change should also not be taken as reason to stop worrying about it, even with policies to reduce the threats, said Krebs: "Whether it will result in a net benefit we simply can't tell."

Julian Hunt, emeritus professor of climate modelling, at University College London, said the report's finding showed “that there would be longer periods of "static weather" and cloud cover, could threaten solar and wind energy sources. This leads to dangerous urban heat island temperatures and droughts. But it also indicates the danger of lengthy, very low, wind conditions, or cloudy conditions – so low-carbon energy alternatives to wind and solar are essential.”

Other issues highlighted by the report include changes in wildlife migration, alterations in species communities as plants and animals fail to move fast enough to thrive, sewer overflows polluting the coast, changes in the soil, erosion from heavier rains, loss of staff working-time from heat stress, changes in fish stocks, and wildfires in drier summers.