What 95% certainty of warming means to scientists

There's a mismatch between what scientists say about how certain they are and what the general public thinks the experts mean, experts say.

WASHINGTON — Top scientists from a variety of fields say they are about as certain that global warming is a real, man-made threat as they are that cigarettes kill.

They are as sure about climate change as they are about the age of the universe. They say they are more certain about climate change than they are that vitamins make you healthy or that dioxin in Superfund sites is dangerous.

They'll even put a number on how certain they are about climate change. But that number isn't 100 percent. It's 95 percent.

And for some non-scientists, that's just not good enough.

There's a mismatch between what scientists say about how certain they are and what the general public thinks the experts mean, experts say.

That is an issue because this week, scientists from around the world have gathered in Stockholm for a meeting of a U.N. panel on climate change, and they will probably issue a report saying it is "extremely likely" — which they define in footnotes as 95 percent certain — that humans are mostly to blame for temperatures that have climbed since 1951.

Related: Scientists set to prepare strongest warning that warming man-made

One climate scientist involved says the panel may even boost it in some places to "virtually certain" and 99 percent.

Some climate-change deniers have looked at 95 percent and scoffed. After all, most people wouldn't get on a plane that had only a 95 percent certainty of landing safely, risk experts say.

But in science, 95 percent certainty is often considered the gold standard for certainty.

"Uncertainty is inherent in every scientific judgment," said Johns Hopkins University epidemiologist Thomas Burke. "Will the sun come up in the morning?" Scientists know the answer is yes, but they can't really say so with 100 percent certainty because there are so many factors out there that are not quite understood or under control.

George Gray, director of the Center for Risk Science and Public Health at George Washington University, said that demanding absolute proof on things such as climate doesn't make sense.

"There's a group of people who seem to think that when scientists say they are uncertain, we shouldn't do anything," said Gray, who was chief scientist for the U.S. Environmental Protection Agency during the George W. Bush administration. "That's crazy. We're uncertain and we buy insurance."

With the U.N. panel about to weigh in on the effects of greenhouse gas emissions from the burning of oil, coal and gas, The Associated Press asked scientists who specialize in climate, physics, epidemiology, public health, statistics and risk just what in science is more certain than human-caused climate change, what is about the same, and what is less.

They said gravity is a good example of something more certain than climate change. Climate change "is not as sure as if you drop a stone it will hit the Earth," Princeton University climate scientist Michael Oppenheimer said. "It's not certain, but it's close."

Arizona State University physicist Lawrence Krauss said the 95 percent quoted for climate change is equivalent to the current certainty among physicists that the universe is 13.8 billion years old.

The president of the prestigious National Academy of Sciences, Ralph Cicerone, and more than a dozen other scientists contacted by the AP said the 95 percent certainty regarding climate change is most similar to the confidence scientists have in the decades' worth of evidence that cigarettes are deadly.

"What is understood does not violate any mechanism that we understand about cancer," while "statistics confirm what we know about cancer," said Cicerone, an atmospheric scientist. Add to that a "very high consensus" among scientists about the harm of tobacco, and it sounds similar to the case for climate change, he said.

But even the best study can be nitpicked because nothing is perfect, and that's the strategy of both tobacco defenders and climate deniers, said Stanton Glantz, a medicine professor at the University of California, San Francisco, and director of its tobacco control research center.

George Washington's Gray said the 95 percent number the Intergovernmental Panel on Climate Change will probably adopt may not be realistic. In general, regardless of the field of research, experts tend to overestimate their confidence in their certainty, he said. Other experts said the 95 percent figure is too low.

Jeff Severinghaus, a geoscientist at the Scripps Institution of Oceanography, said that through the use of radioactive isotopes, scientists are more than 99 percent sure that much of the carbon in the air has human fingerprints on it. And because of basic physics, scientists are 99 percent certain that carbon traps heat in what is called the greenhouse effect.

But the role of nature and all sorts of other factors bring the number down to 95 percent when you want to say that the majority of the warming is human-caused, he said.


http://news.msn.com/science-technology/what-95percent-certainty-of-warming-means-to-scientists

 

You can almost smell the desperation.

 

the reason for the disconnect is that very very scientists are willing to make that claim in peer reviewed papers

"Only 41 out of the 11,944 published climate papers Cook examined explicitly stated that Man caused most of the warming since 1950. Cook himself had flagged just 64 papers as explicitly supporting that consensus, but 23 of the 64 had not in fact supported it.

This shock result comes scant weeks before the United Nations’ climate panel, the IPCC, issues its fifth five-yearly climate assessment, claiming “95% confidence” in the imagined – and, as the new paper shows, imaginary – consensus."

http://wattsupwiththat.com/2013/09/...ven-by-a-new-paper-showing-major-math-errors/

 

So what. the fact is that 97 % of all the world's climatologists and all it's science orgs agree that most of the warming over the last 50 years is due to man.

Science papers don't usually make a specific claim like that.

What are you stupid? You fall for that shit? Wow, you are gullible.

And you still quote bullshit whore denier websites instead of authoritative source like NOAA and NASA. Why is that.

 

There you go again with the 97% nonsense again. 75 out of 77 self-pro-claimed individuals in one study does NOT make it a 'fact that 97% of the world's climatologists' support AGW. 'All it's science orgs' - no not even close - there are a large number of science organizations that have publicly stated their positions against AGW.

Why do you keep re-posting this poltically driven fabricated nonsense which simply is not true?

 

I guess you can't read or are so dumb that you don't know what you are reading. I'm going with the latter.

For the umpteenth time.

Read it. Read it all. Try to comprehend.

http://www.skepticalscience.com/global-warming-scientific-consensus.htm

 

The consensus Cook considered was the standard definition: that Man had caused most post-1950 warming. Even on this weaker definition the true consensus among published scientific papers is now demonstrated to be not 97.1%, as Cook had claimed, but only 0.3%.

Only 41 out of the 11,944 published climate papers Cook examined explicitly stated that Man caused most of the warming since 1950. Cook himself had flagged just 64 papers as explicitly supporting that consensus, but 23 of the 64 had not in fact supported it.

This shock result comes scant weeks before the United Nations’ climate panel, the IPCC, issues its fifth five-yearly climate assessment, claiming “95% confidence” in the imagined – and, as the new paper shows, imaginary – consensus.

http://wattsupwiththat.com/2013/09/...ven-by-a-new-paper-showing-major-math-errors/

 

So you post an article that shows once again that the ONLY survey result showing a 97% concensus is Doran which simply counted 75 out of 77 self-proclaimed climatologists in their results. Read your own article - you appear to have a reading comprehension issue.

 

Typical for Chicken Little types. Anyone and any media source, web site, or print that agrees with one's view is too be accepted as gospel, without question, beyond any doubt. No further query required. To be accepted without even the slightest hint of reservation. The Truth and nothing but the Truth. As good as the word of GOD.

While any and all sources that may pose questions to that view, or perhaps even suggest alternative cause and effects. Sources that may even dispute that view and present evidence to support an alternative view. These sources are just the dupes for evil capitalists, or ".........bullshit whore denier websites......" , the facts quoted cannot be relied on, their view is simply a smoke screen for an darker agenda. Not worth ones time!

I truly pity those who go through life with such a myopic view. Their destined to remain dim-witted, fated to fall for a lot of shit, and thus be perpetually "Gullible".

 

Article? There are three levels of comprehension on that site, references to multiple studies and ways of looking at it and at least one video.

You, like jerm, seem to be nit-picking on trivial points while ignoring the essential truth. I guess.

The essential truth is that science is as sure that man has caused most of the warming over the last 50 years as it is that smoking is bad for the smokers health, and that the vast bulk of that is from CO2 increase from the burning of fossil fuels.

If you guys had just slightly more common sense than crazed ideology, you would understand why this is so. But unfortunately there is literally nothing that will change your mind. With the possible exception of a lobotomy.