My Letter to the APS Council on the climate change review

In my earlier story I recommended people write to an APS councillor to express their opinions on the matter. I slightly adapted my comments from that article and sent the following. Others should feel free to use some of this as a template if needed.

Dear Dr. XXX,

I'm hoping you'll be attending the Nov. 8 APS Council meeting, or able to forward this along to those who will be there. I'm very concerned about this proposal to "revise" the current statement on climate change. As an APS life member I absolutely support the statement as it stands - it's brief but extremely clear, and based on the science of the IPCC reports (the 2007 assessment in particular, where the analyses of the three working groups seem nicely echoed in the three paragraphs of the current APS statement).

The "open letter" referenced in this APS news article - - by contrast, is confusingly worded, and frankly wrong on several counts. It is vastly inferior to the current statement, and I would be appalled if anything like it was adopted by the council. Appended below are my notes on the problems with this proposed statement - which, again, I hope is not seriously being considered.

Thanks for your consideration,

Arthur Smith (APS member XXXXXX)
Selden, NY


Greenhouse gas emissions, such as carbon dioxide, methane, and nitrous oxide, accompany human industrial and agricultural activity.

This slightly restates the second and third sentences of the first paragraph in the current APS statement, but omits the first sentence that clearly states these gases have an effect on climate. Do the authors of this proposed statement actually believe that the effect of greenhouse gases on climate is zero?

While substantial concern has been expressed that emissions may cause significant climate change, measured or reconstructed temperature records indicate that 20th 21st century changes are neither exceptional nor persistent, and the historical and geological records show many periods warmer than today.

Today's temperatures are not "exceptional" in the historical or geological record, as the IPCC report describes (in particular section 6 of the working-group 1 report of IPCC's 4th assessment report - AR4 WG1 sec. 6 - discusses the paleo-climate record: 3 million years ago it was 2-3 C warmer than now). But how can it be claimed they are "not persistent"? Every year from 2001 through 2008 the measured average global temperature has been warmer than all but 1 to 4 years of the entire 20th century (depending on which analysis you look at). What scientific justification is there to claim that the 20th century warming is not persisting?

Moreover, this statement is clearly intended to imply that there should be no expectation of continued increases in temperatures, but a huge weight of evidence points to at least a 2 degrees C transient response for a doubling of CO2, as stated in the IPCC report. Given continued greenhouse emissions (which the first sentence of the proposed statement admits), that certainly brings us into temperature territory that the Earth has not seen since well before human civilization began. "Exceptional" is hardly a precise term, but I think to any ordinary person, higher temperatures than human civilization has ever seen should qualify, and by that definition exceptional temperatures are surely coming unless we cut back on CO2 emissions significantly.

In addition, there is an extensive scientific literature that examines beneficial effects of increased levels of carbon dioxide for both plants and animals.

This includes a radical assertion not backed up by any reference to the actual literature. I have, personally, never heard of a benefit of higher CO2 for animal life. According to this hazard sheet, CO2 leads to blood acidification, at 1% can be hazardous, and 5% is toxic. Granted, those levels are considerably higher than the 0.1% concentration that we might get in the next century under business-as-usual scenarios, but "beneficial"?

As for plant life - the question is whether the increase in CO2 compensates for higher temperatures and expected changes in precipitation, and that also depends on the type of plant (C3 or C4 respiration). This statement is extremely one-sided on the real issues here. Again, where is this "extensive scientific literature" that justifies such a statement of clear benefit? I've attended a lecture from folk at Brookhaven Lab who have been actually doing this research, and they're significantly less optimistic than this statement implies.

Studies of a variety of natural processes, including ocean cycles and solar variability, indicate that they can account for variations in the Earth’s climate on the time scale of decades and centuries.

On a time scale of 1 decade, certainly, variations in Earth's climate are determined by "natural processes" like the solar cycle, volcanoes, and ocean-atmosphere interactions. In fact, climate is not even well-defined for a single decade, since it represents the statistical distribution over all such short time-scale variations. Further in the past, orbital forcings (with ice-albedo and greenhouse-gas feedbacks) clearly account for the glacial-interglacial changes. But no known natural processes can account for the changes in Earth's climate observed in the 20th century. What scientific source is there for this statement that outweighs the very clear analyses the IPCC report is based on? The "can account for" in that context is a strong statement (implying anthropogenic GHG's have had no impact). That is radically opposite to the very well-established science of the greenhouse effect.

Current climate models appear insufficiently reliable to properly account for natural and anthropogenic contributions to past climate change, much less project future climate.

This statement doesn't even make logical sense. Climate models do not predict either natural or anthropogenic contributions to past climate change - they model the *response* to forcings, not the forcings themselves. Forcings are input (from other types of modeling). And in modeling responses they have been tremendously successful - one of the best examples of this is the response of the planet to the Pinatubo eruption's addition of stratospheric aerosols, which was predicted quite accurately by Jim Hansen at least 4 years before the eruption. And of course "climate models" ever since Arrhenius have predicted surface warming from increased CO2, as observed in the 20th century. What analysis of climate models is there in the literature that in any way justifies this statement?

The APS supports an objective scientific effort to understand the effects of all processes – natural and human --on the Earth’s climate and the biosphere’s response to climate change, and promotes technological options for meeting challenges of future climate changes, regardless of cause.

More research is fine, but what this proposed revised statement omits is any call to action for governments or APS members to work to actually reduce greenhouse gas emissions. Of course if anybody seriously believes greenhouse gases have no effect on climate, that would make sense. But there is honestly no dispute on those basic facts of the greenhouse effect in any credible scientific literature on the subject. Any physicist who claims otherwise I would require to please explain the unusually high surface temperature of Venus, among many other straightforward observational confirmations of the situation.