More data needed to support or disprove global warming theory

Reports of global warming are prevalent in the popular press. With the exception of Scandinavia, no major energy tax laws have been passed to date. But environmental pressures may change this, and the change could have a profound effect on refiners.

These are the views of Gerald T. Westbrook, of TSBV Consultants, Houston. Westbrook summarized recent global-warming research, and his position on the subject, at the National Petroleum Refiners Association annual meeting, held Mar. 16-18, in San Antonio.

The greenhouse effect is real, says Westbrook. This occurs when solar radiation passes through a medium (in the earth's case, a thin layer of greenhouse gases) and becomes trapped. The gas layer is transparent to solar energy, but infrared energy (heat) cannot pass through it.

Greenhouse gases include: water vapor, water droplets, CO2, CO, methane, ozone, N2O, and chlorofluorocarbons (CFCs). It is important, however, to distinguish between the two major mechanisms of the greenhouse effect: natural warming and anthropogenic warming (changes in the concentration of greenhouse gases caused by man).

Without greenhouse gases, says Westbrook, the earth's equilibrium temperature would be -18? C. The effect of the gases is to raise the equilibrium temperature to 15? C. Water vapor and droplets are responsible for most of this 33? C. increase.

The concentrations of some greenhouse gases have been increasing due to anthropogenic effects. CO2 has increased by about 29% (to 360 ppm from 280 ppm) since 1880, says Westbrook, and CH4 has increased about 143% (to 1.7 ppm from 0.7 ppm).

Natural or man-made?

In the early 1980s, computer models estimated global warming over the past 100 years to be as much as 2.3? C. By 1986, those estimates had been reduced to 1.0? C., and in 1988, a range of 0.63 ? 0.2? C. was reported. In 1995, a report by the Intergovernmental Panel on Climate Change (IPCC) cited a range of 0.3-0.6? C.

In 1995, Lean said, half of the 0.55? C. increase was attributable to changes in solar input.1 Believers in global warming tend to downplay solar effects, while skeptics argue that anthropogenic forces have almost no effect on global warming.

U.S. vice-president Al Gore, in his book Earth in the Balance, claimed that atmospheric CO2 and temperature move in lockstep. Westbrook asserts that, "The earth's motion anomalies-orbit eccentricity, axial tilt, and wobbles-lead to dramatic changes in insolation, and are the dominant force over [the last 160,000 years]."

Data from the National Aeronautics and Space Administration and its Goddard Institute for Space Studies reveal three temperature trends in recent history:

Warming of about 0.6? C. between 1880 and 1940.
Cooling of about 0.2? C. between 1940 and 1965.
Warming of about 0.4? C. between 1965 and 1995.

These trends combine to produce a total increase of about 0.8? C. since 1880. But Westbrook wonders why the first increase was so large.

"Both aerosol levels and solar activity may apply here," he said. (In this context, the term aerosols refers to dust, soot, marine aerosols, sulfates, and products of biomass burning.) "A plot comparing sun spot cycle length and temperature shows a strong correlation that explains 91% of the variation in the [temperature] data," said Westbrook.

The common thread among recent studies of greenhouse effects is that unique forces are present, in addition to greenhouse gases, and that these forces play a major role.

Computer models

The vast majority of the analysis of the greenhouse effect is concentrated on huge computer models called general circulation models (GCMs). These models represent a significant accomplishment with respect to research and education. But they were never designed for use in the policy arena, says Westbrook, and that has become their major role.

Westbrook compiled a list of the GCMs' shortcomings, both known and potential:

Stability-All GCMs need a "fudge factor" to prevent drift.2
Sensitivity-GCMs' warming predictions (?C. per equivalent CO2 doubling) vary unacceptably between 1 and 5.3
Role of water vapor and droplets-GCMs need an amplification factor for these variables, without which they predict almost no warming.4
CO2 retention-GCMs may exaggerate CO2 retention in the atmosphere.
Aerosols-Believers say incorporation of aerosols into GCMs solves the models' problems, but skeptics say that inclusion of aerosols worsens their accuracy.5 The IPCC reports that ground-based temperature measurements reveal warming of 0.3-0.6? C. over the last 100 years. GCMs, on the other hand, would have predicted a range of 0.8-2.2? C.

Satellite-based measurements show a minor cooling, says Westbrook. With adjustment for volcanic activity and El Ni?o effects, a slight warming is seen, but even that is only 25-30% of GCM predictions.

Future work

Fig. 1 [36948 bytes] shows uncertainties in the effects of various pollutants on global warming. Despite such uncertainties, extensive activity in the policy arena will continue, predicts Westbrook.

"If ever there was a case of the cart before the horse, this is it," he said.

Nevertheless, Westbrook believes the global warming issue should be taken seriously, for several reasons:

CO2 is being added to the atmosphere at an alarming rate.
Some evidence of rapid temperature changes exists.
Aerosols may offset the effects of greenhouse gases.
The Earth Summit agreements are very close to becoming binding.

There are, however, reasons for optimism. Scientific progress in the last 10 years has been impressive, says Westbrook. And the more we learn, the lower the projections become.

Whatever global warming is occurring, most of it is at night and during the winter, and a significant portion of it is caused by natural forces. In addition, says Westbrook, "The biosphere seems to be responding positively to higher concentrations of CO2."

Westbrook summarized his position on the global warming issue:

"We simply don't know the magnitude of the global warming problem. It may be huge; it may be zero. I am convinced that we have the time to get the science right, whether it is 5 or 15 or even 25 years," he said. "We should rein in policy activity, where possible, for 10 years, and we should continue R&D efforts," he added.

"The goal should be to develop an acceptable theory of the climate. We should push energy efficiency wherever we can, and promote tree planting everywhere. And we should search for, analyze, and communicate the true nature of the scientific consensus on global warming, if there is one."

References

1. Lean, J., et al., "Reconstruction of solar irradiance since 1610," Geophy. Res. Letters, Vol 22, 1995.

2. Kerr, R., "Climate Modeling's Fudge Factor Comes Under Fire," Science, Vol. 265, Aug. 9, 1994.

3. Lindzen, R.S., "Absence of Scientific Basis," National Geographic Research & Exploration, Vol. 9, No. 2, 1993.

4. Lindzen, R.S., "Errors Hurt Global Warming Theories," New York Times, Nov. 30, 1991.

5. George C. Marshall Institute, "Are Human Activities Causing Global Warming?," 1996.

6. Schwartz, S.E., and Andreae, M.O., "Uncertainties in CC Caused by Aerosols," Science, Vol. 272, May 24, 1996.

BOOKS
Maintaining Energy Security in a Global Context, by William F. Martin, Ryukichi Imai, and Helga Steeg. Published by Trilateral Commission, distributed by Brookings Institution Press, Dept. 029, Washington D.C. 20042-0029. 117 pp., $9.

This report discusses three aspects of energy security: Limiting the world economy's vulnerability to disruption as dependence on Gulf oil supplies rises; assuring that adequate energy supplies are provided at reasonable prices for rising demand in the world economy over time; and the energy-related environmental challenge.

The HCB Bulk Liquids & Gases Guide, First Edition 1997, published by Intapress Publishing Ltd., 8th Floor, 29 Bressenden Place, London SW1E 5DR, U.K. 288 pages, ?135.

Compiled by Hazardous Cargo Bulletin, the book calls itself the "International Handbook for the Shipping and Terminalling Industries." It presents names, addresses, and telephone and telefax numbers for chemical tanker operators, inland chemical barge owners and operators, cargo tank steel suppliers, coatings and lining suppliers, terminal operators by country, liquefied gas tanker operators, and storage-tank builders, among other addresses.

Interspersed in these listings are articles on the entire spectrum of shipping bulk liquids and gases: regulations, new construction, tanker review, pros and cons of mounded storage for liquefied gases, and other topics.

INDEX of articles OGJ published in 1996 can be ordered for $7.50 from Circulation Dept., Attn. Judy Hernandez, Oil & Gas Journal, Box 1260, Tulsa, OK 74101.