|
02/21/2002
Global Warming's Ups and Downs
The other morning on Marco Island, I started out my predawn
walk under threatening skies but concluded that the rain, if any
was way out over the Gulf. As I walked down the beach, I kept a
watchful eye on the area that looked dark and threatening. The
other eye was on the beach to avoid stepping on the dead fish
washed up by the red tide. When I was about 2 miles away from
our condo, I looked around and found that I should have been
keeping both eyes peeled in back of me, where it was uniformly
threatening. Too late - I was drenched by the time I got home.
Predicting weather, even on a short-term basis and with all our
weather satellites, still is fraught with uncertainty. When it
comes to predicting the earth''s weather over the next few
decades, notably the prediction of global warming, things can get
pretty hot figuratively. As measures are debated to help alleviate
the potential problems of global warming, there has been much
scientific, as well as political wrangling going on. For example,
within the past week or so, President Bush came up with a new
alternative to the Kyoto Treaty dealing with measures to cut
down on the emissions of greenhouse gases. Bush rejected the
treaty early in his term of office.
I''ve deliberately tried to stay away from global warming as a
topic for this column, not feeling qualified to really weigh in
with a valid opinion. Personally, I feel that the evidence I''ve
seen is pretty convincing that global warming does exist and that
strong measures should be taken. At the same time, it''s much
easier to pass the problem along to our children and
grandchildren. This is true especially when one reads or hears in
the media that global warming is overblown or, as in the past
month or so, that new data show that the global warming theory
is in trouble.
In this regard, one of the potential problems that has gotten a
good deal of press for many years is the possibility that, thanks to
global warming, a substantial portion of Antarctica will break off
and/or melt away. The subsequent rise in sea level could
drastically affect the fate of major coastal cities all over the
world, not to mention the loss of seaside resorts and homes. But
wait a minute; we don''t have to worry about that scenario, at
least according to newspaper accounts in recent weeks. For
example, one California paper states that recent "scientific
findings run counter to the theory of global arming." And a
Canadian newspaper headlines "Antarctic ice sheet has stopped
melting, study finds." So we can all relax, right?
Not according to another article by Keay Davidson of the San
Francisco Chronicle appearing in the February 10 Naples Daily
News. The optimistic newspaper articles were based on an
article by Slawek Tulaczyk and Ian Joughin in the January 18
issue of Science. These two researchers found that the flow of
certain ice streams in Antarctica had slowed down and rather
than melting, in these particular ice streams the ice was actually
thickening. Also in January, another group of scientists reported
in Nature that most of Antarctica has cooled since 1966. These
articles were the basis for the optimistic headlines proclaiming
that global warming theory is in deep trouble.
But what about the weather in New Jersey, where I live? We''ve
had the warmest January I can recall and this week it''s supposed
to be 60 degrees Fahrenheit in New York. And when we arrived
in Florida several weeks ago, the Tampa area was posting its
hottest January day on record. Yet this February on Marco
Island has been the coldest I can recall since we''ve been coming
down. (Of course, with highs in the low 70s and high 60s, I''m
not really complaining. It''s been great for my early morning
walk on the beach.)
My point is that the weather swings wildly on both an extremely
local basis and on a global basis. When the authors of the
Science and Nature papers saw the media proclaiming essentially
that global warming was dead, they came forth to forcefully set
things straight. The lead author of the Nature paper, Peter
Doran, stated, "global warming is real and happening right now."
He noted that on Antarctica, although two thirds of the continent
has been cooling down, a third of Antarctica has been warming
up substantially. Not only that but the other continents have
heated up to record high temperatures. In other words, the global
climate can show just as much variety as the weather in different
regions of the U.S.
Indeed, I''ve just finished reading an article titled "Extreme
Responses to Climate Change in Antarctic Lakes" in the January
25 issue of Science, which appeared just a week after the Science
issue containing the ice stream paper that caused all the
commotion. The lead author is Wendy Quayle of the British
Antarctic Survey. The article deals with the effects of global, or
at least local, warming on the lakes of Signy Island, a small
island roughly 400 miles northeast of the Antarctic Peninsula.
This small island, just 4 miles long and 3 miles wide, has a quite
a few freshwater lakes and pools. These lakes are quite sensitive
to changes in temperature and Quayle and her coworkers have
been studying such things as the temperatures of the lakes, the
number of ice-free days, the chlorophyll content of the lakes due
to the presence of algae and the presence of nutrients in the lakes.
The studies cover the period from 1980 to 1995 but some other
data are available from 1950. This article cites a global increase
in temperature of 0.32 degrees Centigrade (about 0.6 degrees
Fahrenheit) in the period from 1980 to 1999. This compares
with a temperature rise in the Antarctic Peninsula of 2 degrees
Centigrade in the past 40-50 years - that''s one part of Antarctica
that''s really cooking!
Not surprisingly, the amount of snow and ice cover and how long
it lasts plays a key role on the temperatures and on the life that
exists in these polar lakes. Because of this, these lakes make
good sensors for environmental changes due to temperature
changes. Mean summer air temperature measurements for the
Signy Island summers dating are available dating back to 1950.
Over the 40 years between 1950 and 1990, the air temperature
went up 1 degree Centigrade. During the study period 1980-
1995, the rise was about 0.5 degrees Centigrade. During that
period the mean winter temperatures for 9 lakes went up 0.9
degrees Centigrade. Since 1951, the permanent ice cover has
declined about 45 percent, open water days in 1993 numbered 63
more than in 1980. The amount of chlorophyll in the lakes
increased almost 3 times over the levels in 1980.
Another consequence of the warming was the increase in the
levels of nutrients in the lakes, notably phosphorus. When the
ice caps first began melting around 1950, the resulting water ran
over ice, which contained little in the way of nutrients.
However, as the ice cover declined the meltwater began to run
over exposed ground. Now the water picks up nutrients from the
soil, plants and microbes and the phosphorus levels in the lakes
rose to 5 times the levels in the first year of the study. You can
see from the above statistics that the lakes are like amplifiers -
the changes are proportionately greater than the temperature
increases.
So, now we''ve seen some data that support the global warming
theory. Note that I said "support", not "prove". Slawek
Tulaczyk, co-author of the ice stream paper in Science is quoted
in the Naples newspaper article as saying that scientists are very
cautious in their choice of words, especially when it comes to
using verbs such as "is", "may be" or "can be". This cautious
approach often gets lost when the science writers and the media
latch on to the papers.
One of the consequences of greenhouse gases, global warming
and the depletion of the ozone layer is the increased need to use
sunscreen. Accordingly, for my first round of golf of 2002, I
applied a liberal dose of Coppertone 45. Sure enough, after a
few holes the sunscreen was leaving my forehead to enter my
eyes. Though not legally blind, I could reasonably blame my
undistinguished performance on the sunscreen. Going into the
18th hole, I only had one bogey (that was my best hole!). At the
18th, however, I found myself about four feet off the green on
the fringe with the cup about 25 feet away. The fringe was this
Zoysia-like grass, not made for accurate putting. Nevertheless, I
drilled that putt straight as an arrow, hit the pin dead center and
holed the putt for my first par of the year. My motto is always
leave the crowd wanting more! Ok, there was no crowd, just our
4-some.
Allen F. Bortrum
|
