Correction appended.

The Obama administration has made "enormous" efforts to cut domestic greenhouse gas emissions, U.S. Deputy Envoy for Climate Change Jonathan Pershing said yesterday.

Speaking in Doha, Qatar, on the opening day of the U.N. climate change conference, Pershing said U.S. emissions peaked "several years ago." He also appeared to take umbrage at a suggestion that America hasn't pulled its weight in the global quest to curb greenhouse gases, citing fuel efficiency measures, financial investments in clean technology and U.S. EPA regulations of power plant emissions.

"I think I would suggest that those who don't follow what the U.S. is doing may not be informed about the scale and the extent of the effort, but it is enormous," Pershing said.

He noted that President Obama pledged at the 2009 Copenhagen, Denmark, climate summit to curb U.S. emissions 17 percent below 2005 levels in this decade.

"Three years later, we're at 8.8 percent down on the route to where we want to go," Pershing said.

Building the Durban Platform?

The comments came amid a typically harried first day of the annual climate talks with environmental activists pushing wealthy countries to act faster and better on global warming and emerging divisions between rich and poor nations.

Diplomats from the United States and Europe described this year's meeting as a "transitional" one that will close out a set of negotiations launched five years ago and set nations on a path to a new global emissions agreement expected to take effect by 2020.

That new agreement was given the green light at last year's meeting in Durban, South Africa, in a document referred to here as the Durban Platform. It would bind all emitters, including the United States and China, to cut carbon.

"It's not that we expect a huge decision here when it comes to the Durban Platform, but we need to come to a good start," said European Commission lead negotiator Artur Runge-Metzger. Noting that the agreement is expected to be signed by 2015, he said this year's discussions must show "political momentum."

Activists also pressed industrialized countries to sign onto a second phase of the Kyoto Protocol. The length of time that second phase will last, as well as what kinds of targets countries will put forward, is expected to be a major battle, though not one that directly involves the United States, which is not a party to Kyoto.

The 'big boys' vs. the 'bad boys'

The Qatari hosts, meanwhile, spent much of yesterday defending their country's oil and gas activities as well as its title of spewing among the highest levels of greenhouse gas emissions per capita in the world.

In doing so, though, conference President Abdullah Bin Hamad Al-Attiyah may have unraveled decades of work done by India, China and other emerging economies to make the case for continuing to pollute.

"I think I said before that I never believe in per capita as a balance for distribution of emissions. I think this is when they calculated just to show that the small countries are the bad boys and the big countries are the big boys," Al-Attiyah said.

"I think we should not concentrate, you know, on the per capita. We should concentrate on the amount each country individually that they produce. Because when you go to the atmosphere, they will never ask you, 'Is this amount per capita?'"

China's total emissions now exceed those of the United States, and India ranks fourth. Both China and India, though, point to their low levels of emissions per capita as proof of the still-needed development in those countries. India has even offered to pledge that its per-capita levels will never reach those of the United States.

Many activists were hoping to see Qatar announce either an emissions pledge or a national strategy yesterday but Al-Attiyah insisted Qatar is already doing its share with a gas flaring program and investments in carbon capture and storage technology.

"Unfortunately until now they have not proven that they take climate change seriously," Climate Action Network International President Wael Hmaidan said of the Qatari hosts.

Correction: An earlier version incorrectly quoted the percentage Pershing gave for the United States' progress toward its Copenhagen climate pledge. The correct number is 8.8 percent.