I wholeheartedly agree with Darren@24

In a more innocent and pragmatic time the goal of environtmental regulations was to replace *dirty* (reactive) sulphur and nitrogen oxides with *clean* (stable) CO2.

Here’s a piece from Hinderacker at Powerline with an interesting discussion from the Hadley e-mails:

http://www.powerlineblog.com/archives/2009/11/025011.php

So, there is good reason to believe that the global cooling fears of the 70′s were well founded due to the effects of U.S. SO2 and NO* emmisions. As American industry began scrubbing for these pollutants, and then Russian industry began shutting down, the greenhouse effect of CO2 became more influential. With unregulated Chinese and Indian industry taking up the slack the effect of SO2 and NO* aerosols have become more influential again. Given an approximately decade feedback loop, this potentially explains the recent stall of “global warming.”

To me, the lesson is that CO2 is not THE overriding forcing that AGW alarmists insist, and that atmospheric geoengineering (ie. terraforming) might pose a much cheaper, quicker and more effective means to counter CO2 greenhouse effects than systematic attempts to reduce CO2.

Darren is also spot on in his discussion of the 95% solution vs the 99.9999% solution. We see this with arguments about defining acceptable levels of arsenic and other toxins in drinking water. In an ideal world, we would like there to be none. Recently the U.S. EPA tightened the allowable concentration of arsenic from 50 parts per billion to 10 ppb, to the dismay of environmentalists who wanted a limit of 1 ppb or less. The Bush administration was denounced for wanting to kill children by coddling polluters, despite the fact that natural background concentrations of arsenic range from 2 – 5000 ppb. Requiring every small water provider to reduce concentrations from an affordable 50 ppb to a more expensive 10 ppb was a hardship, but new technologies have sprung up to make it doable. Bridging the gap from 10 ppb to 1 ppb is not a linear exercise, it’s exponential. As the instrument detection limit of arsenic, or other toxin, is approached the cost of each incremental part per billion to be removed increases 10 fold. This parallels the experience of scrubbing SO2 and NO* from smokestack emmisions and certainly predicts what we will see with any systemic, comprehensive effort to remove CO2. I think that it actually underpredicts because CO2 is so chemically inert. The first 20% – 50% might be relatively painless, but each increment of CO2 removal after that will confront a ever steepening cost curve.