[Vision2020] Heat-Trapping Gas Passes Milestone, Raising Fears

[Art Deco]

  [image: The New York Times] <http://www.nytimes.com/>

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May 10, 2013
Heat-Trapping Gas Passes Milestone, Raising Fears By JUSTIN
GILLIS<http://topics.nytimes.com/top/reference/timestopics/people/g/justin_gillis/index.html>

The level of the most important heat-trapping gas in the atmosphere, carbon
dioxide, has passed a long-feared milestone, scientists reported Friday,
reaching a concentration not seen on the earth for millions of years.

Scientific instruments showed that the gas had reached an average daily
level above 400 parts per million — just an odometer moment in one sense,
but also a sobering reminder that decades of efforts to bring
human-produced emissions under control are faltering.

The best available evidence suggests the amount of the gas in the air has
not been this high for at least three million years, before humans evolved,
and scientists believe the rise portends large changes in the climate and
the level of the sea.

“It symbolizes that so far we have failed miserably in tackling this
problem,” said Pieter P. Tans, who runs the monitoring program at the
National Oceanic and Atmospheric Administration that reported the new
reading.

Ralph Keeling, who runs another monitoring program at the Scripps
Institution of Oceanography <http://scrippsco2.ucsd.edu/> in San Diego,
said a continuing rise could be catastrophic. “It means we are quickly
losing the possibility of keeping the climate below what people thought
were possibly tolerable thresholds,” he said.

Virtually every automobile ride, every plane trip and, in most places,
every flip of a light switch adds carbon dioxide to the air, and relatively
little money is being spent to find and deploy alternative technologies.

China is now the largest emitter, but Americans have been consuming fossil
fuels extensively for far longer, and experts say the United States is more
responsible than any other nation for the high level.

The new measurement came from analyzers atop Mauna
Loa<http://www.nytimes.com/2010/12/22/science/earth/22carbon.html?pagewanted=all&_r=0>,
the volcano on the big island of Hawaii that has long been ground zero for
monitoring the worldwide trend on carbon dioxide, or CO2. Devices there
sample <http://www.esrl.noaa.gov/gmd/ccgg/trends/weekly.html> clean, crisp
air that has blown thousands of miles across the Pacific Ocean, producing a
record of rising carbon dioxide levels that has been closely tracked for
half a century.

Carbon dioxide above 400 parts per million was first seen in the Arctic
last year, and had also spiked above that level in hourly readings at Mauna
Loa.

But the average reading for an entire day surpassed that level at Mauna Loa
for the first time in the 24 hours that ended at 8 p.m. Eastern Daylight
Time on Thursday. The two monitoring programs use slightly different
protocols; NOAA reported an average for the period of 400.03 parts per
million, while Scripps reported 400.08.

Carbon dioxide rises and falls on a seasonal cycle, and the level will dip
below 400 this summer as leaf growth in the Northern Hemisphere pulls about
10 billion tons of carbon out of the air. But experts say that will be a
brief reprieve — the moment is approaching when no measurement of the
ambient air anywhere on earth, in any season, will produce a reading below
400.

“It feels like the inevitable march toward disaster,” said Maureen E.
Raymo, a scientist at the Lamont-Doherty Earth Observatory, a unit of
Columbia University.

>From studying air bubbles trapped in Antarctic ice, scientists know that
going back 800,000 years, the carbon dioxide level oscillated in a tight
band, from about 180 parts per million in the depths of ice ages to about
280 during the warm periods between. The evidence shows that global
temperatures and CO2 levels are tightly linked.

For the entire period of human civilization, roughly 8,000 years, the
carbon dioxide level was relatively stable near that upper bound. But the
burning of fossil fuels has caused a 41 percent increase in the
heat-trapping gas since the Industrial Revolution, a mere geological
instant, and scientists say the climate is beginning to react, though they
expect far larger changes in the future.

Indirect measurements suggest that the last time the carbon dioxide level
was this high was at least three million years ago, during an epoch called
the Pliocene. Geological research shows that the climate then was far
warmer than today, the world’s ice caps were smaller, and the sea level
might have been as much as 60 or 80 feet higher.

Experts fear that humanity may be precipitating a return to such conditions
— except this time, billions of people are in harm’s way.

“It takes a long time to melt ice, but we’re doing it,” Dr. Keeling said.
“It’s scary.”

Dr. Keeling’s father, Charles David Keeling, began carbon dioxide
measurements on Mauna Loa and at other locations in the late 1950s. The
elder Dr. Keeling found a level in the air then of about 315 parts per
million — meaning that if a person had filled a million quart jars with
air, about 315 quart jars of carbon dioxide would have been mixed in.

His analysis revealed a relentless, long-term increase superimposed on the
seasonal cycle, a trend that was dubbed the Keeling
Curve<http://scrippsco2.ucsd.edu/>.


Countries have adopted an official target to limit the damage from global
warming, with 450 parts per million seen as the maximum level compatible
with that goal. “Unless things slow down, we’ll probably get there in well
under 25 years,” Ralph Keeling said.

Yet many countries, including China and the United States, have refused to
adopt binding national targets. Scientists say that unless far greater
efforts are made soon, the goal of limiting the warming will become
impossible without severe economic disruption.

“If you start turning the Titanic long before you hit the iceberg, you can
go clear without even spilling a drink of a passenger on deck,” said
Richard B. Alley, a climate scientist at Pennsylvania State University. “If
you wait until you’re really close, spilling a lot of drinks is the best
you can hope for.”

Climate-change contrarians, who have little scientific credibility but are
politically influential in Washington, point out that carbon dioxide
represents only a tiny fraction of the air — as of Thursday’s reading,
exactly 0.04 percent. “The CO2 levels in the atmosphere are rather
undramatic,” a Republican congressman from California, Dana Rohrabacher,
said in a Congressional hearing several years ago.

But climate scientists reject that argument, saying it is like claiming
that a tiny bit of arsenic or cobra venom cannot have much effect. Research
shows that even at such low levels, carbon dioxide is potent at trapping
heat near the surface of the earth.

“If you’re looking to stave off climate perturbations that I don’t believe
our culture is ready to adapt to, then significant reductions in
CO2emissions have to occur right away,” said Mark Pagani, a Yale
geochemist
who studies climates of the past. “I feel like the time to do something was
yesterday.”




-- 
Art Deco (Wayne A. Fox)
art.deco.studios at gmail.com
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