<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Dec 26, 2010, at 2:08 PM, John Clark wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Dec 25, 2010, at 10:50 PM, Keith Henson wrote:</div><blockquote type="cite"><div><font class="Apple-style-span"><br></font>The *easy* part is making a clean cheap substitutes for fossil fuels.<br>We know how to suck CO2 out of air at a cost of around 100 kWh/t (360<br>kWh per ton of carbon). </div></blockquote><div><br></div>I'm much more interested (and much more skeptical) in a dollars per ton figure than energy per ton. And I'm not even certain CO2 is at the root of the problem, it certainly isn't the most important greenhouse gas, water vapor is, and water vapor is the very thing that current climate models handel so poorly. </div></div></blockquote><div><br></div><div>The bottom line is that there is no good evidence of a dangerous amount of warming or hardly any statistically significant warming at all if you check variation over say the last several centuries. OTOH we know for certain, or darn well should by now, that we are facing a major economic breakdown and pending energy crisis. So why don't we, as rational future minded folks, focus our attention on the real problems and opportunities?</div><div><br></div></div>- s</body></html>