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Scientific revi-

Benign--or Positive--Warming Trends

The best argument for climate alarmism

Given the observed surface warming of

may not be what is known but what is not

sions in the last

the last half century, and particularly of the

known--climate "surprises" from "rapidly

decade have mod-

last two decades, the distribution of the pre-

forced nonlinear systems."2 2 7 Yet as climate

erated the case for

dicted warming would be relatively benign,

model revision and actual data lower the

occurring in the coldest air masses during the

warming estimates, the potentially negative

climate change

coldest times of the year and more often dur-

climatic "surprises" predicated on high

alarmism.

ing the night than during the day. Maximum

warming evaporate also. That leaves the

summer temperatures, which are of more dis-

positive "surprises" from a higher level of

comfort and create more negative climate

C O2 in the atmosphere: a decreasing diur-

consequence in many areas of the world, have

nal cycle, a moderately warmer and wetter

been less affected.2 2 4

climate, and enhanced photosynthesis for a

richer biosphere.

Other unresolved issues are important in

Scientific revisions in the last decade

the debate over climate change and public

have moderated the case for climate change

policy. The apparent incongruence between

alarmism. Scientific thought today favors

steadily rising CO levels and surface tem-

2

greater movement toward the lower end of

peratures for much of the present century,

the warming estimates from climate mod-

namely the "overwarming" prior to 1945 and

els. The scientific justification for the Kyoto

"global cooling" between 1945 and 1975, has

Protocol is more than just unsettled. It is

led to ad hoc adjustment factors in the cli-

speculative and unconvincing, given actual

mate models with sulfate aerosols to recon-

weather records to date and ongoing scien-

cile the data with predicted results.

tific revisions. The more settled side of the

There is also a well-known discrepancy

scientific debate, the positive effects of

between atmospheric temperature readings

higher CO2 concentrations on plant life,

by satellite and balloon sensors (showing a

strongly favors the status quo even before

slight cooling in the lower troposphere,

the political and energy-economic dimen-

where the models predict a stronger "green-

sions of the climate change issue are exam

-

house signal" than at the surface) and sur-

ined. But for purposes of analysis, a

face thermometer readings, which show a

stronger scientific case currently exists for

warming trend over the past 20 years. Bias

assigning a positive externality value to

corrections in the satellite data have less-

C O2 than for assigning a negative one.

ened the discrepancy, but significant differ-

ences remain that, if verified, would suggest

Kyoto Quandaries

that either the surface warming has been

The Kyoto Protocol, which requires signa-

overstated or the surface warming has not

tory Annex 1 (developed) countries to reduce

been driven by anthropogenic greenhouse

global greenhouse emissions by an average of

gas buildup--both signaling vindication for

the skeptics of warming alarmism.2 2 5

5.2 percent from 1990 levels in the 2008­12

budget period, begins the process of stabiliz-

In addition to the increase of surface tem-

ing atmospheric concentrations of anthro-

peratures at a fraction of the rate predicted by

pogenic greenhouse gases believed to be

general circulation models in the last five

responsible for problematic climate change.

decades (0.15°C), sea levels have risen only

Approximately 134 developing countries are

modestly (only seven inches over the last cen-

exempt, including China, which is projected

tury), and extreme-weather events have not

to surpass the United States as the world's

occurred with any more frequency than in

leading CO emitter in the coming decades.

the past.2 2 6 Critics ask, where is the alarmist

2

The Department of Energy and the Clinton

"greenhouse signal," given a 50 percent

administration  project  that  exempt

buildup of the warming potential of green-

non­Annex 1 countries will emit more CO

house gases in the atmosphere to date?

2

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