re: #9 RealismRox

… so that’s totally debunked.

Nothing in science is totally debunked, especially in an area as complex as environment. Carbon dioxide increases the above-ground biomass in most C3 plants (90+ % of species, including many major food crops), often by staggering amounts. The C4 pathway, which evolved to _concentrate_ CO2 does have decreased productivity. Maize is a C4 crop, so not without impact in the U.S. One paper in Science published in 2002 did find a decrease in NPP at CO2 levels > 800ppm in California grasslands as part of a multi-factor study, when NPP was extended to included the root-mass of the plant, not just the above ground portion (previous papers have shown significant increases in above-ground NPP in C3 plants to increased CO2. Mechanisms for the change were suspected to be nutrient limitations, primarily phosphorus.

In last Friday’s issue of Science, an article was published that should give many pause: I’ll do limited quotes, as this is copyrighted material, but do consider it appeared in a top-tier scientific journal — here’s the link for those who’d like to pay-to-read: sciencemag.org

“The latest response from the climate community comes in State of the Climate in 2008, a special supplement to the current (August) issue of the Bulletin of the American Meteorological Society. Climate researcher Jeff Knight and eight colleagues at the Met Office Hadley Centre in Exeter, U.K., first establish that—at least in one leading temperature record—greenhouse warming has been stopped in its tracks for the past 10 years. In the HadCRUT3 temperature record, the world warmed by 0.07C0.07C from 1999 through 2008, not the 0.20C expected by the Intergovernmental Panel on Climate Change. Corrected for the natural temperature effects of El Nio and its sister climate event La Nia, the decade’s trend is a perfectly flat 0.00C.”

The article goes on to state, “Researchers may differ about exactly what’s behind recent natural climate variability, but they agree that no sort of natural variability can hold off greenhouse warming much longer. “Our prediction is that if past is prologue, the solar component will turn around and lead to rapid warming in the next 5 years,” says Rind.”

It also notes that solar variability is a wild card.

I do not doubt that the climate is changing, or that man’s activities have a significant influence. Heck, the climate will change without man’s presence — it certainty has done so in the past. I’m less certain whether we can argue whether the changes coming are good, bad, or a toss-up. I am even less certain that we have the ability to accurately model the consequences of such change, beyond immediate first-order effects. Do we risk what cap-n-trade entails economically on suspect consequential models? Rapid change in economic systems can also be bad.

Not a denier, but a skeptic of over-reliance on models (scientists are supposed to be trained to be skeptical).