Top scientist makes climate plea

World leaders have been urged to put more money into developing new energy technologies to tackle global warming.
Royal Society president Professor Sir Martin Rees wants a publicly funded international research programme, he says in the US journal Science.
Professor Rees says a pledge to increase governments' investments in energy technologies should have been made at the recent G8 summit in Russia.
He describes a "worrisome lack of determination" among world leaders.
'Urgent challenge'
Professor Rees said: "Energy security was a key issue at the St Petersburg summit of G8 leaders last month.
"Their joint communique included many important commitments, but it omitted one crucial pledge - a significant increase in their governments' investments in R&D (research and development) for energy technologies."
More needs to be done to develop new energy technologies that are currently far from market
Professor Sir Martin Rees
He said an "urgent challenge" was to meet global demand for energy, while reducing the impact of greenhouse gas emissions on climate change.
To do this, "more needs to be done to develop new energy technologies that are currently far from market", he said.
Professor Rees suggests money for research could be raised through methods such as carbon taxes, levied initially on the countries with the largest greenhouse emissions.
Energy demand
The BBC's science correspondent Pallab Ghosh says public funding for energy research across the world has halved in real terms since 1980, and in the UK it is now one-tenth of what it used to be.
"According to Professor Rees world leaders are simply not facing up to the challenges of global warming," he said.
"They are neither sufficiently reducing carbon dioxide emissions, nor are they investing enough in developing the technologies that would reduce the world's dependence on fossil fuels."
The International Energy Agency predicts that by 2030 global energy demand will increase by 50%.