UN Secretary-General Ban Ki-moon and former US Vice President Al Gore on Tuesday called on the world to use the coordinated economic stimulus urgently needed to tackle the global economic crisis to launch a long-term 21st century revolution of green growth.

Such a stimulus package would not only jump-start the economy on a path that leads away from the use of global warming fossil fuels by eliminating their subsidies in developed countries, but would also help poor nations develop social safety nets and culminate in a new deal to curb climate change at a meeting in Copenhagen at the end of the year.

"What we need is both stimulus and long-term investments that accomplish two objectives simultaneously with one global economic policy response -- a policy that addresses our urgent and immediate economic and social needs and that launches a new green global economy," they wrote in a joint opinion piece in the Financial Times of London. "In short, we need to make 'growing green' our mantra."

Warning that continuing to pour trillions of US dollars into carbon-based infrastructure and fossil-fuel subsidies would be like investing in sub-prime real estate, the trigger for the present crisis, all over again, the two statesmen said eliminating the US$300 billion in annual global fossil fuel subsidies would reduce greenhouse gas emissions by as much as six percent and would add to global gross domestic product.

"Leaders everywhere, notably in the US and China, are realizing that green is not an option but a necessity for recharging their economies and creating jobs," they said, urging all governments to adopt coordinated green stimulus elements, including energy efficiency, renewable energy, mass transit, new smart electricity grids and reforestation.

They noted that in much of the developing world, governments do not have the option to borrow or print money to cushion the devastating economic blows, and industrialized nations must therefore reach beyond their borders and invest immediately in those cost-effective programs that boost the productivity of the poorest.

"This means increasing overseas development assistance this year. It means strengthening social safety nets. It means investing in agriculture in developing countries by getting seeds, tools, sustainable agricultural practices and credit to smallholder farmers so they can produce more food and get it to local and regional markets," they wrote.