Download 16 Mar 2014

Art Hobson, [email protected]
NWA Times, 16 March 2014
Climate change and the clash of cultures
The general theme of this column has been that a fatal contradiction runs
through these modern times. On the one hand, our economy is based primarily on
science and rational thought, while on the other hand our beliefs remain mired in
primitive instincts and medieval superstitions. We see all around us, most
obviously in places like Syria and more subtly in American anti-intellectualism and
materialism, the consequences of this clash between evidence-based conclusions
and traditional beliefs.
Nowhere is this clearer than in the case of climate change.
Last month two leading scientific organizations, the British Royal Society
and the U.S. National Academy of Sciences, issued a summary for the general
public titled "Climate Change: Evidence & Causes." It's brief, easy to read,
written for non-scientists, and free on the web. It's written in a Q&A format,
providing answers with evidence to 20 questions such as: Is the climate
warming? What role does the sun play in climate change? Why are human
emissions significant? How fast is sea level rising? The report was authored by 12
leading climate scientists, and reviewed prior to publication by 13 others.
Science is never certain. In fact this is one of its great strengths, for only
fools can be absolutely certain. But I've read lots of science in my life, and it
doesn't get much better than this report and the work that backs it up. Here are a
few highlights:
How do we know that climate change is caused by humans? We've known
since 1850 that carbon dioxide (CO2) is central to Earth's energy balance. It
increased by 40 percent since 1800. Analysis of different carbon isotopes shows
that long-buried carbon from biological organisms--i.e. fossil fuels--are the source
of this increase. The observed 1.4 Fahrenheit degree increase in Earth's
temperature since 1900 is consistent with calculations of the impacts of this CO2
increase. The many observed patterns of warming also match the patterns
expected from rising CO2 levels. Finally, calculations using models that simulate
what would have happened if only natural factors were influencing the climate
yield no warming over the 20th century, while models that include the 40 percent
rise in CO2 yield the observed temperature changes.
The warming isn't due to the sun. There's no evidence for long-term changes
in the sun's output over the past century, although temperatures have increased
significantly. Furthermore, computer models show that increases in solar output
would warm the troposphere and the full vertical range of the stratosphere equally,
whereas CO2-induced warming should warm the troposphere but cool the
stratosphere. According to the evidence, the stratosphere has cooled while the
troposphere has warmed.
The present rate of planetary warming is more than ten times that at end of
the last ice age, and is faster than any known warming trend in the planet's history.
Does the recent slowdown of warming mean that climate change is no longer
happening? Not at all. Each of the last three decades was warmer than any other
decade since measurements began around 1850. Warming trends continue in
ocean heat content, sea level, and melting ice.
How confident are scientists that warming will continue during this
century? "Very confident." Continuation of present emissions trends will cause
temperatures to increase by another five to eight degrees by 2100. Even if
emissions stopped today, temperatures wouldn't return to pre-industrial levels for
thousands of years. The current warming is irreversible on human time scales.
The rational response to all this is to put the brakes on fossil fuel use as
rapidly as possible. Yet not only do emissions continue, they actually increase
every year. It's a world problem, with America--which should be a leader--the
chief offender both in terms of per-capita emissions and foolish public
attitudes. There is a relatively painless solution: A tax on carbon emissions that
would be returned to every American as an income tax reduction. The tax would
of course raise the price of gasoline and other fossil fuels, and would be opposed
by many Americans who should know better. We need to start talking about this.
As one indication of public attitudes, the Pew Research Center found last
October that 67 percent of Americans believe there is solid evidence that Earth has
been getting warmer. Breaking this figure down politically, 84 percent of
Democrats and 46 percent of Republicans agreed. But only 25 percent of Tea
Party Republicans agreed. Such figures say a lot about America's cultural divide,
and its corrosive influence on the planet's well-being.