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What We Know and How We Know It

Dan Lashof

Posted February 18, 2010

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This post written with Bob Deans

The ongoing assault on climate science orchestrated by anti-regulation ideologues and supported by oil and coal companies has sown seeds of doubt by magnifying minor missteps by climate scientists and distorting the meaning of Washington DC’s “snowpocalypse.” None of this changes the facts about global warming. So what do we know, and how do we know it?

We know our climate is changing in ways that threaten us all. We know we can curb global warming by reducing carbon pollution. And we know that doing so will make our economy stronger and our country more secure.

That's what we know; here's how we know it.

The past decade was the hottest on record. For the years 2000-2009, the average global temperature was 57.9 degrees Fahrenheit, about 1 degree higher than the 20th-Century average, NOAA reported in January.

NOAA is the National Oceanic and Atmospheric Administration not a political interest group. And when it comes to atmospheric conditions, there is no more credible institution anywhere in the world. Period.

Arctic ice is melting. A third of the perennial ice has vanished in just 30 years. Last September, Arctic sea ice fell to 2 million square miles - down from 3 million square miles in the summer of 1980.  We've lost an area of sea ice equal to the entire United States east of the Mississippi according to the National Snow and Ice Data Center.

We know that from photographs taken by military and space program satellite that pass over the Arctic Circle 14 times every day. 

Arctic sea ice is part of the world's natural refrigerator. It moderates global temperatures. It influences ocean currents. It is fundamental to world climate patterns.

We know, also, what is happening to deserts. They are spreading, fueling armed conflict and putting families on the move in places like Sudan, Kenya and Somalia.

In September, the CIA launched The Center on Climate Change and National Security, to assess the national security risks posed to the United States by widening desertification; rising sea levels; population shifts and increasing competition for food, land and fresh water.

And just this month, in its Quadrennial Defense Review, a seminal strategic document, the Defense Department called climate change "an accelerant of instability" that could have "significant geopolitical impacts" that "may spark or exacerbate future conflicts."

In 1989, then-president George H.W. Bush asked two important questions about climate change: what do we know, and how do we know it?

To answer those questions, NOAA, NASA, the Pentagon, the National Science Foundation, the Department of State and eight other federal agencies mounted one of the most exhaustive endeavors in the history of scientific inquiry, a 20-year study conducted over the course of four administrations - two Republican and two Democratic.

The results were made public last June, in a comprehensive report.

This is how it begins:

Observations show that the warming of the climate is unequivocal.

Unequivocal. Leaving no doubt, open to no misunderstanding. That's what unequivocal means.

The global warming over the past 50 years is due primarily to human-induced emissions of heat-trapping gases,

the report continues.

These emissions come mainly from the burning of fossil fuels (coal, oil, and gas) with important contributions from the clearing of forests, agricultural practices and other activities.

It doesn't get any more definitive than that.

Our planet is warming. Burning fossil fuels is the primary cause.

We can curb the widening destruction it brings by passing comprehensive clean energy and climate legislation.

In recent months, big oil and other opponents of effective legislation have spent scores of millions of dollars trying to defeat it. They have seized on some stolen e-mails from a British university and oversights found amid climate data published by the International Panel on Climate Change to try to undercut the case for change.

Climate deniers have spent more than two years going through the 2007 IPCC report - some 2,800 pages long. So far they have found perhaps two errors and a couple of botched citations, none of which affect the essential findings about climate change.

Certainly science must be scrutinized - rigorously - and subjected to constant reassessment and review.

We must ask ourselves, with vigilance: what do we know, and how do we know it?

When it comes to the fundamentals of climate change, those questions have been asked and answered.

Now it's time to ask something more.

Are we prepared to seize the opportunity for a generation of Americans to go to work leading this country, and the world, into a future of clean and sustainable energy? Or will we remain forever shackled to the outdated energy habits of the past at the expense of the opportunities of tomorrow? 

Are we content to get six out of every ten gallons of our oil from foreign countries like Saudi Arabia, Russia and Venezuela? Or is it time at last to find better ways to spend the hundreds of billions of dollars we spend every year on foreign oil?

Are we going to address a widening scourge that threatens us all? Or will we allow the same old monied interests to thwart needed change and hold us on a course to increasing environmental ruin?

It's time for answers to those questions now. It's time we passed comprehensive clean energy and climate legislation that will put Americans back to work, reduce our reliance on foreign oil and create a healthier future for our children. 

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Carole SheehyFeb 23 2010 10:48 PM

The anti-climate change voices seem to be getting louder lately. The more objective, scientifically-based articles and data that can reach the mainstream media for widespread dissemination, the better. We've got to get these ostriches past their denial, pull their heads out of the sand, and join in the effort to keep our planet habitable going forward.

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