On the same day that climate researchers reported strong new evidence
that the temperatures of the world's oceans are on the rise, teams of
America's leading scientists Wednesday called on Congress to face the
urgent problem of global warming by raising the cost of greenhouse gas
emissions to U.S. industry.
The reality of the planet's changing climate was underscored by a new
report on ocean temperatures that combined years of conflicting data
into what researchers say is a realistic picture of ocean warming and
the National Academy of Sciences, which released three major reports on
the science behind the climate problem and the urgency with which it
must be faced.
There is no longer any doubt that global warming is real, said Pamela
A. Matson, dean of the School of Earth Sciences at Stanford, who led
one of five panels organized at Congress' request to assess the reality
and urgency of global warming and propose measures to cope with it.
"Climate change is occurring," Matson said. "The Earth is warming,
concentrations of carbon dioxide are increasing, and there are clear
fingerprints that link these warming effects to human activity."
End business as usual
The three academy reports issued Wednesday totaled more than 860
pages and represent a dramatic shift from the organization's cautious
approach to climate change in the past. The academy scientists warned
that "business as usual" is no longer possible for American industry and
called on Congress to quickly enact a "carbon pricing system" to curb
the rise in greenhouse gas emissions.
In 2008, American industries emitted the equivalent of 7 billion tons
of carbon dioxide, the academy experts noted. They suggested that the
nation adopt a "greenhouse budget" of permitted carbon emissions that
would range from 170 billion to 200 billion tons of carbon dioxide for
the period from 2012 to 2050, saying it is a "reasonable goal." If
greenhouse gas emissions continue at the 2008 level, the scientists
warned, the budget would be exceeded well before 2050.
"We focused primarily on carbon dioxide because it is responsible for
so much of the problem," said Robert W. Fri, an energy expert and
academy member from the nonprofit, nonpartisan Resources for the Future.
To reach even part of the goal recommended by the academy, either a
"cap-and-trade" system or a tax on carbon emissions or a combination of
both are needed, the scientists said.
They gave a special nod to the cap-and-trade concept. That system
would set limits on how much carbon-containing gases could be emitted by
industries as a whole, and then allow companies that emit little or
none of the gases to sell "carbon credits" to the big polluters.
The issue of cap-and-trade is a thorny political one; the Obama
administration supports such a system and Congress is wrestling with it.
The House passed a bill last year, but it stalled in the Senate, which
deferred it while the health care bill was debated.
Rising sea levels
In a separate report published today, but released Wednesday, in the
journal Nature, scientists from the United States, Britain, Germany and
Japan said they have found "robust" evidence that sea levels have risen
over the past 16 years as the upper layers of the world's oceans have
warmed and caused water expansion. They looked to the ocean for signals
of climate change because the oceans absorb up to 90 percent of the heat
that reaches Earth from the sun.
The oceans have warmed by at least three-tenths of a degree
Fahrenheit since 1993, and where sea levels were rising by only 1
millimeter a year 100 years ago, the rate is now 3 millimeters a year,
said John Lyman, an oceanographer with the National Oceanographic and
Atmospheric Administration. The effects may seem small, but they are
highly significant, he said.
The scientists in the Nature study deployed a global network of more
than 3,200 free-floating sensors across all the oceans, and the sensors
broadcast their readings on temperature, salinity and currents to
The results, they said, are far more accurate than earlier ocean
studies, which resulted in a wide range of estimates because
temperatures were recorded by ships towing instruments called XBTs - for
expendable bathythermographs - and they covered only part of the world.
"If you want to know how the world has warmed, you've got to look at
the upper layers of the ocean," Lyman said. "And it continues to warm."
Academy of Sciences reports
reports can be found at www.nationalacademies.org.