More Forbes denialsm

[Vergent]

http://www.forbes.com/sites/timworstall/2012/12/19/maybe-climate-change-just-really-isnt-a-problem-after-all/

#3

http://www.skeptical...s-negatives.htm

[PhillipS]

http://www.forbes.co...blem-after-all/

#3

http://www.skeptical...s-negatives.htm

Thanks for posting that link. Articles like that would be amusing if they weren't such good examples of willful ignorance. Well, maybe I'm being too harsh - maybe the writer is just exhibiting poor math skills and lack of critical thinking.

Do you suppose it's laziness or stupidity that keep denialists and pseudo-skeptics from doing event simple reality checks? A simple check for climate sensitivity is to look at the temperature record. The BEST project reported that the Earth has warmed about 1.5 C since 1750 - and during that same period man has increased CO2 by 40%.

To roughly estimate an upper bound for climate sensitivity one would assume all of that warming is anthropogenic in nature. 1.5 C / 0.4 = 3.7 C A value of 3.7 C is in agreement with published estimates so that's not out of line .

To roughly estimate a lower bond for sensitivity let's assume half of the observed warming is natural and half anthropogenic. 0.75 C / 0.4 = 1.9 C Again, not too far out of line with other estimates. (I know this SWAG approach ignores a great many factors) So any claim for a climate sensitivity less than 1.9 C or greater than 3.7 C for a doubling of CO2 needs solid supporting data. I'm not saying it would be impossible - just that extraordinary claims require extraordinary evidence, and the Forbes article totally lacks that needed evidence.

People should be careful about thinking we're alright if the CO2 sensitivity is near the lower bound. There are a number of reasons for caution, but two seem so obvious that even a child would understand them.

One, natural warming can't be invoked one moment and ignored the next. If we assume natural warming to calculate a low sensitivity then that natural warming gets added to AGW to determine the total temperature rise we're facing. For my SWAG values above that means adding 0.75 C to 1.9 C for a total of about 2.6 C for a CO2 value of 560 ppm. A global rise of 2.6 C is well over the 'safe' 2 C goal.

Two, there is no evidence at all that CO2 will be stabilized at or below the doubling value of 560 ppm - and every indication that we will blow past 560 ppm and keep burning fossil fuels as long as possible. Here is the full Mauna Loa CO2 record:

And here's the annual increases:

See any evidence of CO2 leveling off? Me neither.

[skierinvermont]

I particularly like the part where they spin the increased risk of flash flooding from heavy downpours as "beneficial slightly increased rainfall."