Some of Yorkshire's leading designers and environmentalists attended Sheffield in a post-oil world which analysed how Britain might look in 2059.

The 120 participants were asked to consider how they would survive without oil and plastic.

The audience was told to prepare for a world in which face-to-face business meetings were rare, and video conferencing had become the norm because long distance travel was causing too much environmental damage.

They were also told to prepare for a world without plastics and businesses had to ensure their buildings complied with stringent energy-efficiency legislation.

Andy Sheppard, of global consultants Arup, said: "Many of the issues surrounding climate change are those that engineers are facing up to now.

"If we are to hit the Government's target of an 80 per cent reduction in emissions by 2050 businesses will have to make genuinely sweeping changes starting now.

"The changes need to come at all levels as different aspects of climate change need different solutions. For example, the emissions due to electricity production can be reduced through national programmes, but there is also a vital need to address the production of low carbon electricity at a local level.

"If we look at transport, there is little chance of there being an 80 per cent increase in efficiency in the next 40 years.

"Electric and hydrogen-powered cars may be on the way but they need to be provided with energy from somewhere. The only solution is for people to change their behaviour. If they don't want to do this, they need to be very strongly encouraged."