WASHINGTON (AP) - Top Obama administration officials head to Capitol Hill today in hopes of making a case for aggressive action on climate change.

The hearing is the first of three planned by California Sen. Barbara Boxer, chairman of the Environment and Public Works Committee.

While Senate Democrats have all but abandoned the likelihood of getting a climate bill passed this year, they hope to show some progress ahead of international climate talks in December.

The White House has made its support clear.

Similar to a House-passed bill, the legislation would cap greenhouse gas emissions from power plants and large industrial facilities. Polluters would have to get permits, and the number of permits would drop gradually to dramatically cut heat-trapping pollution.

Republicans say the so-called cap-and-trade approach is a massive energy tax.