Heathrow would be converted into a giant reservoir by 2035, there could be severe restrictions on flying and driving and farmers would be forced to sell their land to giant agricultural businesses. Greenhouse gas emissions would be controlled by carbon rationing for individuals, which would lead to “significant shifts in lifestyle as everyone tries to stay within budget”.

The Government would ease pressure on the South East by planning to “disperse citizens to three new towns in Dumfries and Galloway, Northumberland and Powys”.

The vision is published today in a report entitled Land Use Futures: Making the Most of Land in the 21st Century. John Beddington, the Government’s chief scientific adviser, who directed the research, said that climate change and the growing population would present Britain with difficult choices about how it used its land.

“Business as usual is not an option over the longer term. The effects of climate change and new pressures on land could escalate, seriously eroding quality of life,” he said.

The report says that the projected population increase of nine million by 2031 and an increase in the number of single-person households would result in unprecedented demand for land for development and put pressure on natural resources such as water. By 2050, hotter, drier summers could reduce river flows by 80 per cent.

The report, compiled by 300 scientists, economists and planners, includes three scenarios to “stimulate thought” and “highlight difficult policy dilemmas that government and other actors may need to consider in the future”.

All the scenarios involve dramatic changes in lifestyles and landscapes in response to climate change. In the most extreme scenario, world leaders hold an emergency summit in 2014 when it becomes clear that the impacts of climate change are going to be far worse and happen much sooner than previously envisaged.

The Government responds by taking control of vast tracts of land and using it to grow wood and crops for biomass power stations. An agricultural productivity Bill requires farmers to increase yields per hectare but most have to sell up because they lack the resources to comply. “The average farm size in the UK increases from 57 hectares to 500 hectares; farms in the East and South East of England increase to 5,000 hectares.”

The report says that satellite images in 2060 would reveal dramatic changes in the countryside. “The landscape is mottled with wind turbines; the patches in the patchwork are bigger; there are more forests and fewer animals; there are fewer vehicles moving along the roads.”

In another scenario, the Government redefines land as a national resource and the rights of landowners are balanced with “society’s rights to public benefits from the services produced by it”. Home ownership falls as people begin to embrace the idea of “stewardship” of shared natural resources.

“People are more interested in leasing or sharing goods and less interested in consumption that threatens sustainability of supply. The UK makes a significant cultural shift away from meeting present desires and towards protecting the needs of future generations.”

The report concludes that failure to manage land in a co-ordinated way could result in severe shortages of resources and “public goods” such as water, wildlife and urban green space.

Professor Beddington said: “Over the next 50 years we cannot manage land in the way we’ve done. We’ve got too many competing issues, so much change going on, and we need to get much smarter about how we manage land as we go on.”