2909 17-Mile Drive © 2000 by Leo Poppoff

Pebble Beach, CA 93953

\(831\) 375-3302

May 25, 2000

Basin Watch

by

Leo Poppoff

SHOULD WE JUST ADAPT TO GLOBAL WARMING?

Whenever someone finds a silver lining in global warming, someone else
comes along and tarnishes it. Most agricultural scientists believe that
boosting carbon-dioxide (an important greenhouse gas) in air will make
plants grow faster, according to an article in the March 25 issue of
Science News. Yet, they don't agree that it would be a good thing.

David Lincoln, biologist at the University of South Carolina, explained
that plants "bathed in extra carbon-dioxide rev up their photosynthesis,
take in the gas, and use the carbon to build new fiber and starch." But
researchers find that as starch content rises, the plant takes in less
nitrogen. And that means less protein.

An entomologist at Western Michigan University, David Karowe, is quoted
as saying that's bad for caterpillars. In his experiments, he fed leaves
grown in carbon-dioxide rich atmospheres to his caterpillars. The little
buggers jammed 40% more food in their gullets, but their growth slowed
by 10%, because they weren't getting enough protein.

Researchers at the University of South Florida studied leafminers in
plants raised in carbon-dioxide rich atmospheres. The miners grew fat,
but more of them starved to death. Other researchers found that some
insects, like aphids, thrive in carbon-dioxide rich atmospheres. On the
other hand, they don't release pheromones that attract other aphids. As
a result, they're easily wiped out by ladybugs and wasps.

Well, most of us would consider it a silver lining if caterpillars,
leafminers and their parasites did poorly as the climate warms up. But
here's the tarnish. If insects are undernourished on a diet of plants
grown in carbon-dioxide rich atmosphere, maybe herbivores (like sheep
and cattle) would also suffer.

According to the Science News article, experiments with sheep at Kansas
State University confirmed that pasture grasses grown in greenhouses
with carbon-dioxide enriched air didn't nourish sheep very well. It took
the sheep longer to put on weight.

But, experiments in New Zealand added a different dimension. When sheep
grazed in carbon-dioxide enriched pastures, the mix of pasture plants
changed. The fraction of legumes increased. Sheep feasted on legumes and
got their protein. Obviously, we have a lot more to learn about how
complicated ecosystems work.

Meanwhile, Michael McCracken, Director of the National Coordination
Office of the U.S. Global Change Program, has a message for us. In a
Knight-Ridder news report earlier this year, he's quoted as saying: "You
can't stop climate change given what we're doing right now." He
advocates doing all we can to cut down the use of fossil fuels. But, he
believes, accumulated carbon-dioxide emissions have already contributed
to global warming. So, he and other experts propose that we start
planning for the inevitable climate changes before doom overtakes us.

His advice is to identify the inevitable changes and prepare for them.
An assessment report on this topic isn't due until later this summer,
but some of the experts have already expressed some of their fears. They
include things we've often heard about: rising sea levels, floods now
expected every 100 years would occur every 20 years, smaller snowpacks
and more rain in the Sierra, and more health problems. There are critics
of the assessment, but they're dismissed as "a small, but well-funded
group of climate warming skeptics."

One of the many organizations formed to deal with global warming issues
(and that's become an industry) is the Pew Center on Global Climate
Change. Their philosophy, also, is to accept the fact that climate is
changing and "to take actions to address its consequences." They believe
businesses can and should take concrete steps now to reduce emissions of
greenhouse gases.

And the Pew folks believe that "we can make significant progress in
addressing climate change and sustaining economic growth in the United
States by adopting reasonable policies, programs and transition
policies." They hope to do all this by educating the public and key
policy makers. The effort is supported by 21 major corporations, most of
them in the Fortune 500. It's kind of surprising to see that
corporations like Amoco, Dupont, Shell, PG&E, and Toyota agree that the
climate is changing, and that they should address the consequences,
which includes reducing their emissions.

A Pew Center survey found that 61% of U.S. opinion makers (whoever they
might be) believe that global warming is a real environmental problem.
Another 18% believe it will happen in the future. And only 10% are
nonbelieivers. They don't say what the remaining 11% think. When the
survey was analyzed according to political affiliations, it was found
that more Democrats believe warming is happening now -- still, some 2/3
of Republicans believe it's happening now or will happen.

So, it seems that climate change is in vogue, and we ought to adapt.
Yet, besides advocating the reduction of carbon-dioxide emissions, the
experts seem to be short of ideas on how to adapt.