[classicman]

COPENHAGEN — Ray Weiss looks at the chanting protesters, harried delegates and the 20,000 other people gathered here for a global warming summit and wonders: What's the fuss all about?

Weiss, a geochemist who studies atmospheric pollution at San Diego's Scripps Institution of Oceanography, says the numbers at the core of the debate in Copenhagen are flawed.

Specifically, he says the cuts that countries including the USA are proposing in greenhouse gas emissions are difficult to measure and highly susceptible to manipulation by government officials and companies.

"I don't see the point in doing all this if the numbers are so far off," Weiss said, shaking his head as he watched conference attendees hurry by Thursday. "When you hear politicians tell you that they can measure these things, just because they passed a deal in Copenhagen, I think you should take that with a few grains of salt."

Most of the summit's attention has focused on exactly how much countries will commit to cutting emissions of gases that data suggest are causing the earth to warm. Yet some scientists, legal experts and delegates say the hardest part of any deal in Copenhagen will be measuring — and then enforcing — whatever politicians decide.

Those two issues are "the iceberg on which the entire conference could founder," says Peter Goldmark, a program director for the Environmental Defense Fund, a non-profit group.

The Obama administration has proposed a 17% cut in greenhouse gas emissions by 2020, compared with levels in 2005. Most European countries have offered more ambitious cuts, while China has pushed a target that would allow its carbon dioxide output to continue to grow with its economy, though at a slower pace.

In a study last year, Weiss and colleagues took air samples and found that levels of nitrogen trifluoride, an industrial gas 17,000 times more potent than carbon dioxide as an atmospheric warming agent, were four times above what industry estimates had suggested.

He says monitoring equipment must be significantly upgraded around the world to prevent similar fudging of data if a deal is reached in Copenhagen.

Todd Stern, a lead negotiator for the U.S. delegation, says he's pushing for a system that, after Copenhagen, "allows countries to look at each other and get confidence that everybody is doing what they said they were doing."

However, governments in India and China — which is the world's biggest carbon emitter — have resisted draft proposals that would allow for international verification of data.

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