When President Obama participates in the Copenhagen negotiations this week to draft a new agreement on global climate change, he will become the first American president to personally attend key climate negotiations.

The president's announcement that he will attend the Copenhagen meeting has already had a positive impact. World leaders who were previously reluctant to go, such as the prime ministers of China and Canada, have announced that they too will participate.

Obama recently announced that the United States will set a goal of reducing its greenhouse gas emissions by 17 percent from their 2005 level by the year 2020. This number is consistent with a bill already passed by the U.S. House of Representatives, and is in the ballpark of legislation being considered by the Senate.

This proposed decrease should not be very difficult to achieve. Most of the reductions could come simply from the more fuel-efficient automobiles that Detroit is beginning to produce, and from more efficient energy use in industry, households and commercial buildings. These are measures that we need to take anyway, to enhance national security by reducing the demand for imported oil, and to save money in economically tough times. We do not need to adopt a controversial scheme such as "cap and trade" to achieve this goal.

While the U.S. as a whole will benefit from using energy more efficiently, a few industries may see a decline in the demand for their products. Among these would be coal producers, oil refiners and gas station owners. Some of them have lobbied hard against any climate agreement, and will continue to put pressure on the Senate not to ratify any treaty.

Options to address these concerns include creating new "green" jobs in coal-producing states, providing incentives for refiners to export more of their products, and facilitating the transition of "gas" stations to "gas and recharging" stations for the new generation of electric vehicles that are likely to become increasingly popular as a way of reducing emissions. O'ahu, with its compact size and high population density, could be a leader in this area.

Major developing countries such as China and India have for many years made setting any emission goals contingent on the United States setting its own targets to substantially lower emissions. Many of them are likely to be disappointed at the president's announcement of a modest 17 percent reduction by 2020. This target implies that each American would still emit about twice as much carbon dioxide as each Frenchman, German or Japanese, who have roughly the same standard of living as we do. The president did announce a larger reduction target of 83 percent by 2050, but the scientific community would like to see this achieved sooner.

Each American emits about four times as much carbon dioxide as each person in China, and about 15 times as much as each Indian. Hundreds of millions of people in those countries still live in poverty, although both countries have gone a long way in reducing the gap between the haves and the have-nots. It would be unrealistic to expect them to start reducing their absolute emissions until a much larger share of the population breaks the poverty barrier.

Shortly after Obama's announcement of the U.S. emissions target for 2020, China announced that by the same year it would reduce its carbon intensity (the amount of carbon dioxide emitted per unit of economic output) by 40 to 45 percent compared to 2005. India has also offered to substantially reduce its emission intensity.

President Obama's participation in the Copenhagen climate summit is being welcomed around the world as an indication that the U.S. is finally willing to take action against this common threat and to revitalize a conference that many had until recently written off as unlikely to produce a breakthrough. Even though a final agreement has been postponed until 2010, the chances for consensus on the way forward are much better than they were just a few weeks ago.

Toufiq Siddiqi is president of Global Environment and Energy in the 21st Century and an adjunct senior fellow at the East-West Center. He was a lead author for the Intergovernmental Panel on Climate Change, which shared the 2007 Nobel Peace Prize with Al Gore. He wrote this commentary for The Advertiser.