(New York) -- Global temperatures are rising, the summer Arctic ice cap will likely
disappear in about seven years, irreversible loss of permanent ice in Greenland has
already occurred, the level of carbon dioxide in the atmosphere is increasing inexorably,
and potential solutions are complex and not immediate.
That was the just part of the grim assessment Friday of the impact of human-induced
climate change on the Earth by some of the best and brightest scientists in the U.S. The
scientists gathered Friday at the New York Academy of Sciences for a symposium on
climate and energy sponsored by the Camille and Henry Dreyfus Foundation. The
symposium was sobering for the audience of about 70 scientists who listened to
descriptions of the rapid and large scale changes the planet is undergoing and to the hard
numbers about how difficult it will be to reverse the trend.
"Global melting is a far better description" of what is underway than global warming,
Harvard University atmospheric chemist James Anderson after a talk that set the tone for
the rest of the symposium. Anderson noted that the human population that was a mere
2.3 billion in 1945 had increased to 6.5 billion by 2006. By 2050, 9.6 billion people are
projected to inhabit the planet, he said, and along with people, comes a relentless
increase in the demand for energy. In 1945 the global energy demand was about half a
terawatt (a trillion watts). The energy demand now is two terawatts, and by 2050 it is
expected to double to four terawatts.
Despite the growing political and societal recognition of global warming as a serious
problem, the use of carbon-based fuels is still increasing dramatically, Anderson said. "China is building a coal-fired power plant every two weeks, and they are all open flue
(without scrubbers or other technology to clean the emissions), he said. The 2005-06
projections of carbon dioxide levels in the atmosphere by the International Panel for
Climate Change have already been exceeded "and the ink is barely dry on the report.
We're exploding above it."
In a discussion of "forcing mechanisms" - systems that break down and force faster
breakdowns of other systems - Anderson noted that the result of the rapid melting of the
Arctic ice cap is the loss of the thermal shield for the Greenland ice sheet, which is nearly
1.9 miles thick. The melting of the ice cap is not causing sea levels to rise, because
Arctic ice is floating in the ocean. However, the Greenland ice sheet is on land, and if it
melts entirely, the water it adds to the oceans would cause sea levels to rise almost 23
feet.
The Greenland ice is already melting at a rapid rate, and to press his point, Anderson
showed images of what just 6 to10 feet of sea level rise would mean to Boston,
Manhattan, and Florida. Boston resembled an archipelago, lower Manhattan, including
Wall Street, was submerged, and the southern tip of Florida vanished beneath the waves.
To press his point even further, he told the gathered scientists that "the loss of
permanent ice just this last year has been remarkably large and that loss is irreversible."
Ralph Cicerone, the president of the National Academy of Sciences and one of the leading
researchers on climate change, told the scientists that given the complexities of the
world, "the bottom line is we really should expect more from science and technology (to
mitigate global warming) than we can expect human behavior to change." The
constraints on attacking global warming are many, he noted.
Nations view their access to energy as a security issue, he said, and the U.S. has vast
coal reserves, as does China. "It is unlikely that people will quit using coal," Cicerone
said. "It is the domestic source of energy."
Financial costs of energy are also critical, he said, especially to poor countries, where
development 'is going to be retarded by high energy costs." While nuclear power offers a
carbon free source of electricity, there is continuing concern about the safety of
operations and nuclear waste. Add to that the growing issue of nuclear proliferation, and
the problem gets more complex.
Cicerone mentioned Senator John McCain's call for rapid construction of 45 new nuclear
power plants, but said that would still leave the problem of energy use in the
transportation sector, with millions of vehicles that depend on oil. And while 45 nuclear
power plants sounds like a big number, Anderson noted earlier in the day that more than
200 nuclear power plants would have to be constructed globally each year just to keep up
with growing demand. Another speaker noted that, given the 45-year lifetime of nuclear
power plants, a new one would have to be built everyday "forever" just to meet demand.
Cicerone also said that it is clear from recent precise measurements of solar irradiance of
Earth that the "peak-to-peak" variation during regular solar occilations is significantly less
than one percent. "Until 10 or so years ago, we were free to say that maybe the Sun
was involved (in climate change). We can't say that anymore."
In a "science must" list that concluded his talk, Cicerone said researchers must look hard
at the options for mitigating climate change, communicate better with political leaders
and the public, and do more work on biofuels from non-food crops, on nuclear
reprocessing and waste issues, and on energy storage.
Wind and solar energy hold great promise for the future, several scientists at the meeting
noted, but how to store the energy remains an enormous technical problem. Much of the
rest of the meeting dealt with that issue, as scientists detailed their research into "artificial photosynthesis," which one described as the process of creating an "artificial
leaf."
The growing problem of climate change "is an issue that is no longer Republican or
Democrat," Anderson said at the conclusion of the symposium. "It is security, foreign
policy, and energy policy. It is an issue that crosses all aspects of life. And it is an issue
where there is great hope, because it isn't and issue that divides the house."
