OSLO - A rising population will make it harder for the United States to make 2050 cuts in greenhouse gas emissions than for Russia and some other rich nations with shrinking populations, a Reuters survey showed.

Leaders of the Group of Eight agreed in July to cut developed nations' emissions by 80 percent on average by 2050 in a costly shift to renewable energies. They said the target could aid a U.N. climate pact due to be agreed in December.

But the goal -- if implemented by each nation -- would allow Russian citizens to emit almost twice as much as Americans in 2050, according to Reuters comparisons of emissions and U.N. Population Division projections.

The biggest contrast is between the United States and the other industrialized countries. The demographic differences with Russia are stark, Brian O'Neill, a scientist at the U.S. National Center for Atmospheric Research, said of the data.

Some countries could say: 'how come your emissions can be more than twice ours in a world where we're all meant to be doing our fair share? said O'Neill, who also works at the International Institute for Applied Systems Analysis in Austria.

Americans, with population growth projected at almost 60 percent from 1990 to 2050, will have to share falling emissions rights among ever more people. A projected 20 percent population fall for Russia would cushion the impact of emissions cuts.

Each American would emit 3 tonnes of greenhouse gases in 2050, down from 24 in 1990, if President Barack Obama achieves his goal of an 80 percent cut in national emissions from 1990 and the population rises to 400 million by 2050.

The projected 116 million Russians would have 5.7 tonnes of greenhouse gases per year in 2050. Populations of Japan and Germany are also set to fall over the period.

FRENCH LEAST

French citizens would have the lowest emissions in 2050, at 1.7 tonnes, since their emissions were less than half Russian or U.S. levels in 1990. Italians would have 1.8 tonnes each, Britons 2.1, Japanese 2.5, Canadians 2.7 and Germans 3.4.

Obama and EU nations want to cut by 80 percent from 1990 levels, but the G8's goal was less precise as part of a global strategy to avert heatwaves, rising sea levels, floods, droughts and more powerful storms.

It said cuts of at least 80 percent should be in aggregate for the rich and be from 1990 or more recent years.

Astrid Schulz, a climate research analyst at the German Advisory Council on Global Change (WBGU), said the data showed the difficulties of working out fair cuts.

You can say that some countries have growing populations so they should have more rights to emit, she said.

Or you might say that some have more need for heating, some have more need for cooling. One Russian suggestion was that you should also look at the distance between metropolitan areas to decide. Bigger distances between towns -- as in Russia -- means more need for transport burning fossil fuels.

A WBGU study suggested a carbon dioxide budget for 2010-50 that would amount to yearly allowances of about 2.7 tonnes for everyone in the world. Countries could buy and sell quotas.
O'Neill noted that the G8 goals were not set in stone and could be adjusted in coming years.

The G8 goal has been criticized by poor nations for omitting mid-term 2020 goals more relevant for a U.N. climate treaty due to be agreed in Copenhagen in December.

Latest talks on the pact ended in Bangkok on Friday with no breakthroughs on emissions. Developing nations want the rich to cut by between 25 and 40 percent below 1990 levels by 2020.

Population is rarely discussed at the climate talks as many developing nations say it smacks of interference in development by imposing birth control.

David Satterthwaite, of the International Institute for Environment and Development (IIED), said population growth in poor nations was often exaggerated as a factor in emissions.

The world's population is set to rise to 9 billion by 2050 from about 6.8 billion now, meaning more demand for energy, water and food. But many countries with high population growth, such as in Africa, have extremely low greenhouse gas emissions.

It's consumption that drives dangerous climate change, not population, he said. There is at most a weak link between population growth and rising emissions of greenhouse gases.

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