Most global industrial companies that emit a lot of greenhouse gases are not adequately detailing their climate strategies in U.S. financial filings, two studies by environmental and investment groups showed on Wednesday.

The United States may soon take the mantle as the global leader on climate change in part because of its strong research and development on energy, said oil historian and analyst Daniel Yergin.

Global emissions of the main greenhouse gas carbon dioxide will jump more than 39 percent by 2030 without new policies and binding pacts to cut global warming pollution, the top U.S. energy forecast agency said on Wednesday.

Nearly 200 nations are set to meet late this year in Copenhagen to hash out a new agreement to control greenhouse gases as the Kyoto Protocol expires in 2012.

The U.S. government will reverse a Bush administration policy and increase the role of scientists in setting air standards for criteria pollutants harmful to human health, Lisa Jackson, the administrator of the Environmental Protection Agency, said on Thursday.

President Barack Obama's tough fuel economy program for vehicles could put another damper on the struggling ethanol business, because the alternative fuel packs a lower energy content than gasoline.

Canada's oil sands emit more carbon dioxide than average crude so developers need a clearer picture of where greenhouse gas regulations are headed to find the best way to tap the giant resource, experts said.

US electricity generators support compromises being reached by Democrats in the House of Representatives on proposed climate legislation, saying the changes would soften the impact on power bills.

U.S. President Barack Obama's administration issued a draft rule on Tuesday aiming to cut greenhouse gasses emitted by biofuels but confirming his predecessor's target for production of corn-based ethanol.

President Barack Obama's administration will face a big test on fighting climate change when it seeks to determine if ethanol, the top US alternative motor fuel, cuts greenhouse gas emissions.

President Barack Obama will direct the heads of three US agencies to make the biofuels industry cleaner and encourage output of ethanol made from non-food crops, according to a draft memo obtained by Reuters on Monday.