Image caption Supplies of many commodities including wheat could be affected by climate change

Climate change abroad will have a more immediate effect on the UK than climate change at home, a report says.

Research by consultants PWC for Defra says the UK is likely to be hit by increasingly volatile prices of many commodities as the climate is disrupted.

It warns that global production of some foodstuffs is concentrated in a few countries.

These are likely to suffer increasing episodes of extreme weather.

The report says there will be opportunities for the UK from climate change but these are likely to be far outweighed by problems.

What's interesting is that threats from climate change overseas appear an order of magnitude higher than domestic threats Richard Gledhill, PWC

The opportunities include the ability to export British know-how and reduced shipping costs if the Arctic becomes ice-free. The Arctic looks likely to be a big business opportunity; research estimates suggest that it is likely to attract more than £64bn of investments over the next decade.

Food spikes

The biggest threats are increased volatility in food prices and protectionist measures over food, like India's ban on selling rice.

"What's interesting is that threats from climate change overseas appear an order of magnitude higher than domestic threats," PWC's Richard Gledhill told BBC News.

"This doesn't just refer to the most vulnerable countries like the small island states... climate events in developed countries could damage the UK economy by impacting on food and other resources. We could also suffer damage to assets from events like the floods in central Europe or Superstorm Sandy; this all feeds back into the UK economy."

The report warns that as the climate changes, there will be pressure for the UK to increase its aid budgets (already under threat from back-bench Conservatives).

The report is a follow-up to the recent UK Government Climate Change Risk Assessment (CCRA) which assessed domestic threats and opportunities and the Foresight study into international climate change.

It is based on the UN's "medium CO2 emissions scenario" which is broadly aligned with the 2C maximum temperature increase - a target that is unlikely to be met. That means the study is on the optimistic side, it says.

The paper draws on research from Chatham House describing climate change as a multiplier of other threats.

"Already, price volatility of resources is the new normal," lead author Bernice Lee told BBC News.

"The political implications of this are strong for all countries. Environmental change, including water scarcity and extreme weather will continue to constrain production and transport of key resources and this only looks as though it will get worse."

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