Climate change cannot be stopped, so the government needs to develop realistic policies that will slow it down, according to one expert.

Speaking at the Tenant Farmers Association's 25th anniversary conference this week, the University of London's Emeritus Philip Stott said media-hype and the lack of a robust energy policy over the past 30 years had been major problems.

"We are walking into danger if we think we can stop climate change - we can't, but we can mess up the British economy. Energy security for Britain is a very serious issue and we need a realistic policy that will slow down climate change. But let's not be conned that we can stop it."

In terms of the effect on the climate, emitting gases and not emitting gases were equally unpredictable, but politically it is not something that is talked about, Professor Stott said.

"Don't be taken in by the current politics around climate change - be very cautious as there are agendas attached. As farmers, the only thing you have to worry about is to adapt. What we want from government policy is flexibility. We don't want to place farming in a straight jacket."

Flexibility is particularly important for tenant farmers considering growing energy crops, or going into other long-term energy projects, he noted.

More important than climate change, water management will be the number one issue in the future, Professor Stott said, suggesting that some form of pricing mechanism will be needed.

"We still treat water as a free good in Britain, and for the past 30 years, we have put-off measures that will help manage water use. We will have to value it for any pricing mechanism to work."