Dr. Albrecht Glatzle

Filadelfia 317 - Chaco

9300 Fernheim

Paraguay                                                                  5.08.2007

Scientific American

415 Madison Avenue

New York N.Y. 10017-1111

U.S.A.

Letter to the Editor: The Physical Science behind Climate Change,

August 2007, 48-57

Dear Sir,

I am not a climate scientist but a careful observer of the discussions going on about that topic, as political actions - justified as efforts to stop global warming - start to become ever more harmful for the economies of developing countries.

There are many omissions and half truths in your article which prevent me from taking it too seriously. Why didn’t you mention the established fact that ice cores from the Antarctica and Greenland show that CO₂ concentrations in the atmosphere are following and not leading temperature change? If there is so much CO₂ reinforcement of temperature and the natural radiative forcing of Solar Energy is so small and uncertain, why then did ice ages return and interglacial periods stop? You did not mention water vapour being by far the most important greenhouse gas (95%), nor CO₂ emitted by human activity being responsible for less than 1% of total CO₂ emissions. No word that methane concentrations in the atmosphere are declining. There is no confirmed theoretical or empirical evidence in the science literature of a significant temperature rise due to an increase of CO₂ in the atmosphere. New studies of balloon and satellite data do not resolve the discrepancy you mention between warming of the surface and the atmosphere. Warming of the Lower Troposphere keeps being below that expected by modelling if significant greenhouse gas effects were going on (Christy et al. 2007). Meanwhile Urban Heat Islands are expanding and Land Use in general keeps changing, affecting surface readings, while Lower Troposphere satellite measurements indicate that the increase in temperature stopped five years ago.

How can you know pre-industrial CO₂ levels? Ice core bubbles certainly don’t tell you. They provide a relative but not an absolute measurement of CO₂-concentration, as diffusion behaviour, reaction speed etc. of CO₂ as a function of temperature, time and pressure in the air bubbles are not understood. And Callendar (1958) was obviously very selective in his analysis of historical CO₂ measurements in order to be able to show a consistent increase over time. Recent published work by Ernst Beck puts that historical CO₂ record in doubt.

Furthermore your article pretends consensus among scientists, which in reality does not exist. The famous quoted number of 2500 consenting scientists includes everyone involved in the IPCC effort, whether agreeing with its reports or not. While surfing the internet I clearly got the impression that ever more scientists (even those listed in the IPCC report) disagree with the Summery for Policymakers. This is a political consensus paper between country representatives and not a peer reviewed scientific paper as claimed in your article. Particularly there is no consensus whatsoever among scientists on your claim that present global temperatures are highest since the last 1300 years. Mann’s famous hockey stick has been widely rejected by his own colleagues and the present IPCC report no longer features this former poster boy. The temperature graphs you show virtually represent recovery from the Little Ice Age. And your modelled figures on human induced temperature change over the past 100 years do not impress me at all. I have sufficient experience with models on other items to know that - with dozens of poorly understood variables and finely tuned programs - you can model anything you like and obtain any result desired. In the past, too many predictions of future scenarios have shown to be mistaken (e.g. Dennis Meadows 1970). How can you distinguish between human and natural radiative forcings with the error-bars you show in your graph, not even mentioning water vapour as the overwhelming natural and partly anthropogenic forcing? Also your images of the Arctic do not convince me of the shrinking sea ice. Since I have seen the Kilimanjaro photos presented by Al Gore I at least consider that your images as well could be a cheap showmanship, as Arctic ice is known to be oscillating. Al Gore’s photo taken 30 years ago shows Kilimanjaro after a snowfall event. On my own photo of Kilimanjaro taken in November 1976 the glacier extent looks pretty much the same as in Al Gore’s photo shot recently.

In summary, your article confirms my impression that arguments of the scientific community claiming human induced global warming are getting progressively weaker, more selective and more desperate. I take them as a battle of retreat in an attempt to defend the generous research funding experienced during the past two decades.

Dr. Albrecht Glatzle,

Filadelfia, Paraguay