It is impossible today to get a 'treaty' ratified that would cause America to obey CO2 limits set by any outside body, for a number of reasons.  So Democrats in Congress have been trying to make CO2 the purview of the Environmental Protection Agency(EPA), which gives it sweeping authority to regulate and penalize businesses.

Republicans, more skeptical than not on a CO2 basis for global warming, want that authority removed completely and have been trying to get the Energy Tax Prevention Act of 2011 passed, which keeps the EPA from being able to unilaterally regulate American industry.     So Democrats held a hearing to try and slow it down.

As predicted, both sides claimed to care about science first.    The Democrats produced experts who showed evidence that CO2 was the primary culprit in climate change, though thankfully for science overall they did not try and endorse any particular public policy.  The Republicans produced experts who noted that the planet is warming but...the reasons are unclear, which is obviously less convincing.   Still, both sides agree on climate change these days, so we are making progress.

Unclear or not, we have to grant that hurting the American economy even more (what little industry is left in America) if we aren't sure of cause and effect (and incurring even more unintended consequences) is a bad idea.  One of the experts rightly noted that the populist movement to ban DDT had nothing at all to do with science but instead was activism and the unintended consequences have been millions of dead kids per year and replacement pesticides far worse than DDT.    A fair point, though it's unlikely less CO2 will cause millions of children to die - but there are unintended consequences and they need to have a valid impact analysis, which hasn't been done yet inside the EPA, which basically exists to stop business.

As data continues to accrue, the arguments will  continue to be refined.   Christopher Field, founding director of the Carnegie Institution's Department of Global Ecology and Professor of Biology and Environmental Earth System Science at Stanford University, spoke of research on the effects of rising temperatures on agriculture, showing crop yields dropped sharply above certain temperatures. With corn, he said, even one day at 104 degrees can cause a 7% yield loss.   At 104, according to one study, photosynthesis stops entirely (Mohan K. Wali et al., “Assessing Terrestrial Ecosystem Sustainability,” Nature&Resources, vol. 35, part 4 October–December 1999, pp. 21–33.)

“Major food crops and cotton show little sensitivity to rising temperatures until you reach a threshold. That’s why people are generally not aware of these sensitivities,”  he said.  Which is a terrific point.    Because we haven't yet reached the panic threshold is no reason to deny it exists or do nothing to prevent getting there.   Both parties have to care about agriculture because food is a strategic resource and both groups claim to care about farmers.

No hype, no exaggeration about mass extinctions or 30 foot sea rises, just real data that shows warming can have a short-term effect that practical people need to be concerned about.   Does that mean the EPA is the appropriate agency to deal with this?   No, something as important as the environment and the economy will not be served by a group that only exists to stop industry and it was a mercenary tactic in the first place - a policy issue this important needs to be accountable at the very top, with taxpayers and elected officials and not appointed bureaucrats.

The subcommittee is expected to approve the bill later this week.