Another version of the National Academy of Sciences global warming story, comment on slashdot, followed by story.
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"Stop getting carried away with something that has not been proven scientifically."
Hypothetical question for you, You're crossing a road, first thing in the morning. You're still maybe half asleep, late night and all that.
Suddenly you hear a noise. You look up from your reverie to find there's a huge great truck barrelling down the road toward you, horn blaring.
So what do you do? Do you think "Hmm, this is an rare scenario. The truck could exist, but I also have to consider that I may in fact be still asleep and dreaming this encounter. What data can I collect to determine if actiion is truly warranted in this case?"
Do you do all that, or do you get out of the frigging way first and then run your analysis? I bet I know what most of your ancestors did in analagous situations.
See, the thing is that science never proves anything. That's not a flaw in science, it's methodology. Scientists have long discarded modus ponens [wikipedia.org] as the logical basis for the scientific method, in favour of modus tollens [wikipedia.org]. What that means is that we don't try to prove things, because we recognise that we may not yet have all the facts. Instead we propose a explanation that seem to fit the facts and we try and disprove it.
The thing to note here is that if we wait for science to prove that global is happening, we'll still be waiting in billions of years time. Even if the Sun the should expand to swallow the earth and engulf us solar plasma, we;ll still be waiting, because that's not what scientists, do!
What they do do[1] is get out of the way of oncoming traffic.
If you want to be scientific about this, you need a counter theory, and it has to be falsifiable. There has to be a test we can conduct that to prove it wrong. Preferably one that doesn't involve waiting a thousand years to see if the climate flips state back to the Cambrian Era.
Give me a set of criteria that, if they are satisfied, you will regard as sufficent evidence for taking action against global warming and I will accept that you may have a pont. Otherwise, all you're doing is saying "Bah! Youse scientist dunt never nothing nowhow" only in an fancy accent.
Me, I vote we get out of the way of the truck
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Study says Earth's temp at 400-year high
By JOHN HEILPRIN, Associated Press WriterThu Jun 22, 11:10 AM ET
The Earth is the hottest it has been in at least 400 years, probably even longer. The National Academy of Sciences, reaching that conclusion in a broad review of scientific work requested by Congress, reported Thursday that the "recent warmth is unprecedented for at least the last 400 years and potentially the last several millennia."
A panel of top climate scientists told lawmakers that the Earth is running a fever and that "human activities are responsible for much of the recent warming." Their 155-page report said average global surface temperatures in the Northern Hemisphere rose about 1 degree during the 20th century.
The report was requested in November by the chairman of the House Science Committee, Rep. Sherwood Boehlert (news, bio, voting record), R-N.Y., to address naysayers who question whether global warming is a major threat.
Last year, when the House Energy and Commerce Committee chairman, Rep. Joe Barton (news, bio, voting record), R-Texas, launched an investigation of three climate scientists, Boehlert said Barton should try to learn from scientists, not intimidate them.
The Bush administration also has maintained that the threat is not severe enough to warrant new pollution controls that the White House says would have cost 5 million Americans their jobs.
Climate scientists Michael Mann, Raymond Bradley and Malcolm Hughes had concluded the Northern Hemisphere was the warmest it has been in 2,000 years. Their research was known as the "hockey-stick" graphic because it compared the sharp curve of the hockey blade to the recent uptick in temperatures and the stick's long shaft to centuries of previous climate stability.
The National Academy scientists concluded that the Mann-Bradley-Hughes research from the late 1990s was "likely" to be true, said John "Mike" Wallace, an atmospheric sciences professor at the University of Washington and a panel member. The conclusions from the '90s research "are very close to being right" and are supported by even more recent data, Wallace said.
The panel looked at how other scientists reconstructed the Earth's temperatures going back thousands of years, before there was data from modern scientific instruments.
For all but the most recent 150 years, the academy scientists relied on "proxy" evidence from tree rings, corals, glaciers and ice cores, cave deposits, ocean and lake sediments, boreholes and other sources. They also examined indirect records such as paintings of glaciers in the Alps.
Combining that information gave the panel "a high level of confidence that the last few decades of the 20th century were warmer than any comparable period in the last 400 years," the academy said.
Overall, the panel agreed that the warming in the last few decades of the 20th century was unprecedented over the last 1,000 years, though relatively warm conditions persisted around the year 1000, followed by a "Little Ice Age" from about 1500 to 1850.
The scientists said they had less confidence in the evidence of temperatures before 1600. But they considered it reliable enough to conclude there were sharp spikes in carbon dioxide and methane, the two major "greenhouse" gases blamed for trapping heat in the atmosphere, beginning in the 20th century, after remaining fairly level for 12,000 years.
Between 1 A.D. and 1850, volcanic eruptions and solar fluctuations were the main causes of changes in greenhouse gas levels. But those temperature changes "were much less pronounced than the warming due to greenhouse gas" levels by pollution since the mid-19th century, it said.
The National Academy of Sciences is a private organization chartered by Congress to advise the government of scientific matters.
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HEATING UP: The Earth is the hottest it has been in at least 400, maybe more.
SCIENTISTS AGREE: The National Academy of Sciences studied tree rings, corals and other natural formations, in part, to conclude that the heat is unprecedented for potentially the last several millennia.
HUMAN FAULT: Human activities are responsible for much of the recent warming, the Academy says.
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