The Chicken Littles who had the last word on the International Panel
on Climate Change tell us that the sky is falling again.
The panel of scientists comprising the IPCC recently reported on the state
of, and potential outlook for, earth's climate. Doubts, disagreements and
contradictory data can be found in the body of the report. But the group
who wrote the executive summary, the only part that will be widely read,
pretty flatly assert that humans are causing global warming.
Based on the executive summary and the policy options presented in it, environmentalists
say the world's governments must take drastic action now to halt the cataclysmic
consequences of such a change. Analysts at the World Watch Institute, for
example, call for an overhaul of our energy and transportation systems,
ending the fossil fuel economy. Such policies would cost our nation billions
of dollars.
Before we head for cover, let's consider whether the sky really is falling,
or whether some Chicken Littles in the ranks of scientists have been led
down the garden path by a figurative acorn, in the form of computer climate
model data, falling on their heads.
Proponents of the theory of global warming, or, as is now fashionable, "global
climate change," depend on two bits of evidence and computer models.
First, ground-level measurements of global mean temperature indicate that
earth has warmed between 0.3 and 0.6 degrees Celsius in the last century.
Second, atmospheric carbon dioxide (CO2), a primary greenhouse gas (those
gases without which most animal and plant life would not exist), has increased
by approximately 25 percent in the last century and a half.
When you put these facts in the computer models, global climate change theory
says that the earth's current warming is due to the increase of CO2 in the
atmosphere, caused primarily by the use of fossil fuel. According to the
models, absent a severe and immediate reduction in the level of CO2 put
into the atmosphere, the earth will warm further, causing all manner of
calamities from melting polar ice caps which would raise ocean levels, flooding
small islands and coastal regions, to increased hurricane activity and severe
droughts, which would cause massive crop failure.
The IPCC report's executive summary predicts that if no further action is
taken to curb greenhouse gas emissions, we can expect an increase in temperature
somewhere between 0.8 and 3.5 degrees Celsius over the next 100 years. Interestingly,
this figure is well below the amount of warming forecast just four years
ago. In fact, with every new report, the range of warming falls. At this
pace, in a few years scientific doomsayers will be talking about the next
ice age again. (We haven't forgotten that that was this same group's doom
and gloom scenario in the 1970s.)
Even if the current figure is correct, the increase is well within the natural
range of known temperature variation over the last 15,000 years. Most of
the earth's plant life evolved in a much warmer, CO2-filled atmosphere.
In fact, the predicted warming would affect primarily night-time temperatures,
lessening the number of frosty nights and extending the growing season.
However, there is little evidence that increased CO2 has had more than a
small part to play in this century's temperature increase. Most of the warming
occurred before the 1940s, before the widespread use of automobiles. In
fact, from 1938 to the present, we have actually experienced a cooling trend.
Indeed, satellite data, the most reliable climate evidence that we have,
show no evidence of warming.
So why do scientists agree that we must take drastic action now? Well, they
don't. Some scientists are proclaiming impending disaster, but others of
at least equal repute say the evidence of global warming is questionable
at best. So this is not a question of proven science versus a bunch of know-nothings.
And why do they agree, as the executive summary says, that we should take
drastic action now to curb fossil fuel use, limit economic growth in established
countries, and condemn less-developed countries to continue in their less-developed
circumstances, and increase unemployment and misery all around? They don't
agree with that either. Even some of climate change theory's foremost scientific
advocates acknowledge that there is nothing we can do now to prevent global
climate change that we won't be able to do 10 years from now.
A far better course of action is to keep studying, keep learning, and keep
improving our data until we understand what, if anything, is really happening.
Then we can take action that will allow economic growth and a higher standard
of living and keep our planet livable. Both must be accomplished together;
we must not sacrifice one to achieve the other.
The National Center for Policy Analysis is a public policy research institute
founded in 1983 and internationally known for its studies on public policy
issues. The NCPA is is headquartered in Dallas, Texas, with an office in
Washington, D.C.