Amid the disappointments of the recent Copenhagen climate change conference, there was a common tendency among observers to lump China and India together, since they were the largest among the developing countries that insisted they would not accept absolute limits on emissions of greenhouse gases until they had achieved a higher level of economic prosperity for their people, comparable to that of the larger European countries. Both countries have indicated that they are willing to reduce their carbon intensity (which is defined as carbon emissions per unit of economic output).

In addition, China and India are the two most populous countries in the world, both rely largely on coal (the commercial energy source with the highest emissions of carbon dioxide) and both rank among the top four total emitters of carbon dioxide from energy use — with China having overtaken the United States in this measure last year, and India now ranking fourth.

However, on closer examination there are important differences between China and India in regard to the climate-change picture. For one thing, at recent growth rates, China's per capita income, which currently averages around $5,420 per year (in purchasing power parity), would double in about seven years, and reach the current level of the larger European countries — around $34,000 — in about 25 to 30 years.

China has explicitly stated that its emission intensity would be reduced by 40 to 45 percent from its current levels by 2020. To achieve this goal, China has launched a massive renewable energy program, and another to improve energy efficiency. It is likely that China's emissions would keep growing at a smaller rate until about 2025, and then stabilize or decline in concert with those of the major industrialized countries.

Meanwhile, India's current per capita income level of $2,740 is only half that of China's and its carbon dioxide emissions are only about 30 percent of China's. According to the World Development Indicators, India has about 300 million people living below the poverty line, a much larger number than in China. It may thus take India about 40 years to reach Europe's per capita income level, more than a decade longer than China.

From the carbon emission perspective, however, India has one big advantage — it is giving special emphasis to developing information technology, pharmaceuticals and the service sector, which are less energy and carbon intensive than the manufacturing and heavy industry sectors that have been the backbone of China's rapid development. India also has had an impressive wind power program for more than 20 years, and has access to the large hydropower potential in areas adjacent to the Himalayas.

Despite their differences, the bottom line for China, India and other large developing countries is that for them to even consider setting some absolute emissions limits for the long term, it is essential that the United States, where the per capita income is $46,000 per year, also pass limits. President Obama has suggested a modest reduction of 17 percent from 2005 emissions by 2020, and substantially larger reductions by 2050. The rest of the world is watching to see whether such limits will be ratified by the U.S. Senate.

The reality, however, is that few politicians in most countries, including the U.S., are willing to sacrifice jobs for climate protection measures, even if those measures may benefit the country and the world as a whole. One option to help legislators get past such concerns might be to provide special incentives for job creation in green industries such as energy efficiency improvements and renewable energy technologies.

Many states, including Hawai'i, have set or are setting goals to obtain specific percentages of their electricity from renewable energy, and this trend should be accelerated. Not only would this help the United States in meeting its emission targets, but it would keep the country at the leading edge of technology in this important area, and develop the expertise to assist China, India and other developing countries in achieving their goals for addressing climate change.

Toufiq Siddiqi is an adjunct senior fellow at the East-West Center and president of Global Environment and Energy in the 21st Century. He has participated in several international projects addressing climate change options for China and other Asian countries, and was a lead author for the Intergovernmental Panel on Climate Change, which shared the 2007 Nobel Peace Prize. He wrote this commentary for The Advertiser.