A Truly Expert Opinion On CO2 and Global Warming

Wed, 04 Apr 2007 17:29:23 -0500

Asset B22674 Posted By GWHunta

I appreciate and completely agree with your concern about coming generations.

This is why the vulnerability framework is of such value as it permits scientists to estimate what are

the largest threats today, and in the future, and adopt the appropriate mitigation and/or adaptation

actions.

Such an assessment must consider threats on all space scales from local to global.

However, with respect to risk due to the addition of CO2, in terms of both a threat to the climate

system, and to the environmental system in general, Jim Hansen (and others) claim about how we are

approaching a “tipping point” is an opinion; it is not based on scientific peer reviewed studies and

certainly is not a well accepted view among most climate scientists.

Their gross overstatement, presumably are made to force policy action, and the media have picked up

on their extreme positions (it certainly sells news).

I agree that the added CO2 is a climate forcing that we should limit, but it is not the only important

climate forcing, and may not even be as important as aerosol and land use/land cover change forcings

in affecting climate as we show in our new paper:

Matsui, T., and R.A. Pielke Sr., 2006: Measurement-based estimation of the spatial gradient of

aerosol radiative forcing. Geophys. Res. Letts., accepted.

I realize that this is a technical paper, but it provides a peer-reviewed documentation as to why these

spatial heterogeneous forcings are so important.

To address the issue of human climate forcings, we need to move beyond the almost exclusive focus

on the radiative forcing due to CO2.

On your suggestion to poll climate scientists, this is, of course, a worthy idea.

However, new insight is never achieved by majority vote, but rather by mavericks proposing new

science, which is accepted if it can not be scientifically refuted.

Comment by

Roger Pielke Sr. State Climatologist Emeritus