A leading US economist has called for the four economic superpowers - the United States, European Union, India and China - to participate in an international programme to fight global climate change.
"If any one of these four economic powers refuses to participate in an international programme to reduce carbon, we cannot succeed in stabilising global temperatures," says Yale University President Richard C Levin, who is an economist.
"Given current levels of emissions in the US and Europe, and the projected growth of the Chinese and Indian economies, we simply cannot make the reductions required on a global scale without the cooperation of the United States, the European Union, China, and India," he said.
In a recent speech at the University of Copenhagen as part of a series of lectures in preparation for the 2009 UN Summit on Climate Change, Levin also suggested adoption of a carbon tax or emissions quota on a global level while encouraging organisations to take steps voluntarily to reduce their carbon footprint.
Levin said that either a carbon tax system or a tradable allowance system could be designed efficiently, but that the latter may be more equitable.
"Developing countries will strongly resist a uniform global carbon tax, which they would perceive as placing upon them an unfair burden; yet different taxes across nations would distort investment incentives," Levin said.
"By contrast, agreement on a global cap-and-trade system could take account of a country's stage of development by assigning more stringent reduction targets to developed countries and less stringent ones to developing countries."
"Regardless of the equitable adjustments made in distributing national quotas, as long as allowances are tradable internationally, a uniform price for carbon will result, creating a solution that would be both equitable among nations and efficient in the allocation of investment."
As part of a comprehensive sustainability strategy on its large campus, Yale University has reduced its own greenhouse gas emissions by 17 per cent since committing to a steep reduction in 2005, Levin said.
Additional projects planned by the university will produce a comparable further reduction within several years, said Levin, who has directed Yale to cut its greenhouse gas emissions to 10 per cent below its 1990 level by 2020.
Planned projects at the university that will produce additional reductions in Yale's carbon emissions include the installation of a new cogeneration power plant, the adoption of sustainable building design and construction standards, the use of hybrid vehicles and other sustainable transportation measures, and use of solar and wind power on campus.
"Nearly all of these projects require up-front investment, but the good news is that most of the actions we have taken to date have brought sufficient energy savings to yield a positive economic return," said Levin.
"Based on our experience, I am convinced that just about every large organisation that carefully examines its energy sources and consumption will find many investments that have an economic payoff," he said.
Yale's strategy to shrink its carbon footprint calls for a mix of conservation measures, the use of renewable energy on campus, and direct participation in carbon offset projects.
Yale has been working actively with other universities on efforts to gather data and set targets regarding greenhouse gas emissions, as well as exchanging best practices related to sustainability.
Among those groups are the International Alliance of Research Universities, of which Yale and Copenhagen are members, the Ivy Plus group and the Northeast Campus Sustainability Consortium, which Yale chairs.