May 8, 2009

Having it both ways-again

Here is yet another example of being able to use natural variability as an excuse for cold temperatures while discounting them when it suits your purposes.

Via Tom Nelson
FROM-Bangor Daily News

Scientist: Harsh winter not from global warming

ORONO, Maine — Yes, a state record was set this winter when a temperature of 50 degrees below zero was recorded Jan. 16 in Aroostook County.

That doesn’t mean the phenomenon of global warming has slowed or stopped, said Martin Hoerling, a meteorologist at the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory in Boulder, Colo., as has been suggested in popular books and by politicians.....

“The climate system isn’t moving along a smooth curve,” Hoerling said Thursday morning in the University of Maine’s Barrows Hall during his keynote address to the 17th annual Harold W. Borns Jr. Symposium. “There’s variability … and by and large this variability is due to natural ocean atmospheric fluctuations from one year to the next...."

...Hoerling also serves as chairman of the U.S. Climate Variability and Predictability Program, known as CLIMAR, which is part of the World Climate Research Program. Hoerling said data show that after 30-40 years of warming, temperatures seemed to have plateaued rather than continued to rise since 1998, and that 2008 was one of the coldest years in very recent history. Some people have drawn the conclusion that global warming is over, he added, or that the scientists’ models and measure-ment tools were flawed.

One could point to the Jan. 16 record as proof that global warming has stopped, Hoerling said, but one day, year and decade aren’t enough to prove a trend.

....Hoerling said data show the current rate of warming is unusual in the context of the last millennium. At the same time, he said, the amount of carbon dioxide in the air has increased by 80 parts per million in the last 100 years. That level of buildup compares to a similar rise that took 5,000 years after the ice age.

The central idea of Hoerling’s address — that occasional highs and lows such as the January record are anomalies in the big picture — is one that also is key to the Climate Change Institute’s work. ....

By having this knowledge of what the natural variability is, we can see that, well, the only way this would be happening is by adding the greenhouse gases,” Jacobson said. “The recent additions from humans are the only way we can explain the last 30 or 40 years of warming. Climate is so complicated and there’s so much vari-ability.”

But not so long ago Hoerling was using his considerable resources to discount the influence of natural variability, specifically natural ocean atmospheric fluctuations (El Nino) as being a contributor to warm temperatures. Of course his was all done in the cyberwag world of computer models so it must be true.

Greenhouse gases likely drove near-record U.S. warmth in 2006

Greenhouse gases likely accounted for over half of the widespread warmth across the continental United States in 2006, according to a new study that will be published 5 September in Geophysical Research Letters, a publication of the American Geophysical Union. Last year’s average temperature was the second highest since recordkeeping began in 1895. The team found that it was very unlikely that the 2006 El Niño played any role, though other natural factors likely contributed to the near-record warmth.

...The research team, led by Martin Hoerling at the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Lab (ESRL) in Boulder, Colorado, also found that greenhouse gas increases in Earth’s atmosphere enhanced the probability of U.S. temperatures breaking a record in 2006 by approximately 15 fold compared to pre-industrial times. The authors also estimate that there is a 16 percent chance that 2007 will bring record-breaking warmth.....

...To assess the role of greenhouse gases in the 2006 warmth, the researchers analyzed 42 simulations of Earth's climate from 18 climate models provided for the latest assessment by the Intergovernmental Panel on Climate Change (IPCC)....

For a final check, the scientists compared the observed 2006 pattern of abnormal surface temperatures to the projected effects of greenhouse-gas warming and El Niño temperature responses. The U.S. temperature pattern of widespread warming was completely inconsistent with the pattern expected from El Niño, but it closely matched the expected effects of greenhouse warming


But regardless according to the best available science

Feb 8, 2007 Testimony

Global Climate Projections: The 2007 IPCC Assessment Statement of Gerald A Meehl Senior Scientist NCAR

...Hypothetically, if concentrations of greenhouse gases could have been stabilized in the year 2000, a committed warming of about 0.1C per decade averaged over the period 2000 to 2020 would occur, with smaller warming continuing after that. Of course there are ongoing increases of greenhouse gases, so the models project that no matter what emissions scenario is followed (not taking into account possible large volcanic eruptions that we are not able to forecast but would produce temporary cooling a year or two after the eruption), the combination of climate change commitment and additional warming from increasing greenhouse gases would result in a warming of about 0.2C per decade over the next two decades

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