Schools in the south of England could be left without grass playing fields by 2020 because of pressure to be more environmentally friendly, a former Downing Street adviser has warned.

Most schools will have to generate their own energy over the next decade as councils try to cut carbon emissions, Robert Hill told the annual conference of the Association of School and College Leaders.

“By 2020, I would expect most schools to have to be self-sufficient in terms of energy,” Mr Hill said. “This could be done by digging into the ground to extract heat.

“In the south of England, there will be insufficient water to maintain school playing fields anyway, so these will be dug up and replaced by all weather pitches,” he predicted.

Local authorities will become part of a “cap and trade” scheme to limit carbon emissions in 2011. Schools are responsible for about half of council emissions, Mr Hill said. “Schools are their biggest opportunity to make an impact quickly,” he said. “Schools will have to cut emissions sharply over the next 10 years.”

The Government has pledged to open the first zero-carbon schools by 2016 as part of the Building Schools for the Future programme, which will refurbish or rebuild all secondary schools.

But Robin Nicholson, chairman of the zero-carbon task force for schools, told The TES last year that it would be “bloody difficult” to achieve. There will need to be a radical expansion of renewable energy sources if the target is going to be reached, he said.

Mr Hill, a former adviser to both Tony Blair and former education secretary Charles Clarke, pointed to an Ofsted report that said sustainability was still a peripheral issue at most schools. He said that would have to change.

His comments on climate change coincide with the launch of a wider project that Mr Hill is running for the ASCL, investigating issues facing schools in 2020.