UNITED NATIONS - UN Secretary-General Ban Ki-moon and former U.S. Vice-President Al Gore have called on world leaders to use the coordinated economic stimulus urgently needed for tackling the global economic crisis to launch a 21st century revolution of green growth. "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 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 $300 billion in annual global fossil fuel subsidies would reduce greenhouse gas emissions by as much as six per cent and would add to global gross domestic product. "Leaders everywhere, notably in the US and China, are realising 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 industrialised nations must therefore reach beyond their borders and invest immediately in those cost-effective programmes 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. As the third plank of the programme it is essential that a robust climate deal be reached in Copenhagen in December to replace the Kyoto Protocol limiting the greenhouse gas emissions of industrialized nations, which expires in 2012. "A successful deal in Copenhagen offers the most potent global stimulus package possible. With a new climate framework in hand, business and governments will finally have the carbon price signal businesses have been clamouring for, one that can unleash a wave of innovation and investment in clean energy," they declared. "Copenhagen will provide the green light for green growth. This is the basis for a truly sustainable economic recovery that will benefit us and our children's children for decades to come," they concluded. "With so much at stake, governments must be strategic in their choices. We must not let the urgent undermine the essential. Investing in the green economy is not an optional expense. It is a smart investment for a more equitable, prosperous future."