What do you think of Hansen's rebuttal to the 'impending ice age' argument?

Question

"at most, the decrease from the mean irradiance of recent decades is ~0.1% yielding a climate forcing of about -0.2 W/m2. The current rate of atmospheric CO2 increase is ~2 ppm/year, yielding an annual increase of climate forcing of about +0.03 W/m2 per year.

Thus if the sun remains “out”, i.e., stuck for a long period in the current solar minimum, it can offset only about 7 years of CO2 increase...Speculation that we may have entered a solar-driven long-term cooling trend must be dismissed as a pipe-dream."

Page 14: http://www.columbia.edu/%7Ejeh1/mailings...

So who do you think is right - those who argue that reduced solar activity is driving us toward global cooling and possibly even another ice age, or Hansen who argues that at most a weak solar cycle will offset 7 years of anthropogenic warming?

Answer 1

All you scientist wanna be's need to put away the books and go spend some time in the woods. Clear your heads and wake up with an appreciation for your natural environment and not just the words you spew.

Answer 2

I am worried about both a ice age and global warming.  

Answer 3

Not particularly convincing. I am not saying that we are headed for an "ice age", but Hansen's rebuttal of the idea isn't all that persuasive. Hansen really only focuses on the direct effect of a reduction in irradiance, and of course that change is too small to account for any large change in temperatures. The direct effect of a change irradiance is interesting, but obviously, it is just a small part of the story--the reduction in irraidiance (along with several other solar variables) would have profound effects on the hydrological cycle, wind patterns, ocean currents, etc.. I suspect the reason Hansen doesn't really touch on these points is because they are not particularly well understood.

Richard wrote

"I still find Dr. Hansen very credible, along with all the rest of the mainstream scientific organizations "

Dr. Hansen isn't mainstream, and I find it surprising that you would consider him as such.

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Edit:

Ken wrote

"His recent activism (whatever one may think of that) in no way discounts several decades of highly regarded research experience in this field."

I never said it did, never implied it, never even thought it. But his recent activism ( last 20 years or so) along with his outlandish claims are precisely what puts him at the "upper end of mainstream" (I would tend to label him as outside of mainstream).

Answer 4

I haven't seen any theories about an impending ice age.  Is there one?  I looked a few months ago, but found nothing in the scientific literature using the "Web Of Science" search engine at the University of Oklahoma Library.  It finds plenty about global warming and climate change.

I think he is just wasting his time responding to skeptics who make a choice to ignore reality.  They will remain skeptical no mater what, but still think they are the only people on the planet who have it right, despite what climatologist say.  

Answer 5

Bob326 wrote: "Dr. Hansen isn't mainstream, and I find it surprising that you would consider him as such."

He may be at the high end of mainstream, but you might want to do a little more research into how frequently Dr. Hansen is cited by other climate scientists before asserting he isn't mainstream:

Hansen was rated #15 in this analysis:

http://esi-topics.com/gwarm/authors/b1a....

And this list of recent scholarly publications doesn't exactly have the appearance of someone on the fringe of science:

http://www.columbia.edu/~jeh1/#publicati...

His recent activism (whatever one may think of that) in no way discounts several decades of highly regarded research experience in this field.

Answer 6

I'd say he might be right...if the Sun's only influence on the Earth was through its "irradiance".  All evidence to date would indicate otherwise.

Answer 7

Nature, not man, is to blame, Gore critic insists

By Steve Lyttle

McClatchy Newspapers

Related

CHARLOTTE, N.C. — One of the world's foremost meteorologists Friday called the theory that helped Al Gore win a share of the Nobel Prize "ridiculous" and the product of "people who don't understand how the atmosphere works."

William Gray, a pioneer in the science of seasonal hurricane forecasts, spoke to a packed lecture hall at UNC Charlotte and said humans are not responsible for the warming of the Earth.

His visit, arranged through the meteorology program at the university, came on the same day that Gore was honored for his work in support of the link between humans and global warming.

"We're brainwashing our children," said Gray, 78, a professor at Colorado State University. "They're going to the Gore movie ('An Inconvenient Truth') and being fed all this. It's ridiculous."

"It bothers me that my fellow scientists are not speaking out against something they know is wrong," he said. "But they also know that they'd never get any grants if they spoke out. I don't care about grants."

William M. "Bill" Gray (born 1929) is a pioneer in the science of forecasting hurricanes.[1] In 1952 he received a B.S. degree in geography from George Washington University, and in 1959 a M.S. in meteorology from the University of Chicago, where he went on to earn a Ph.D. in geophysical sciences in 1964.

Answer 8

As a skeptic I hope he is right.  I would rather deal with measures to reduce co2 rather having a mini ice age coming.  

But it looks like he is covering his reputation.  In essence what he is saying that we will have seven years of declining temperatures or "noise". How many years of "noise" must we go through before he admits he is wrong.  

Answer 9

Sounds like a simplistic back of the napkin WAG that does not factor in the probability of a continued decrease in TSI over the next three decades as well as a significant water vapor negative feedback.

Answer 10

I don't know why professionals trust a guy who says the following:

"One of my research interests is radiative transfer in planetary atmospheres, especially interpreting remote sounding of the Earth's atmosphere and surface from satellites. Such data, appropriately analyzed, may provide one of our most effective ways to monitor and study global change on the Earth. ***The hardest part is trying to influence the nature of the measurements obtained, so that the key information can be obtained.***"

He's basically saying he doesn't collect measurements objectively - he INFLUENCES THE NATURE OF THEM.  A fancy way of saying he throws out numbers that doesn't fit his worldview IMHO.  I'd love to corner him and make him elaborate on that sentence.

Answer 11

I don't think much of the rebuttal or the argument.

Ultimately I think this argument falls within the margin of error you see when scientists try to predict the weather or earthquakes. Argue all you like, it will be what it will be.

The good thing about arguments is they allow you to view the facts and fictions about the topic.

The bad thing about arguments is often people are so driven to prove them self right that it clouds their judgement and objectivity.

The proven facts are that the mean temperature of the world is rising, the arctic and antarctic ice is melting, and the oceans are rising. These are all measured phenomenon. (Note: U.S. Land Surveyors are aware that because we measure land elevations as feet above sea level, we had to adjust everything because sea level changed in the last thirty years)

The question is, are these measured facts enough to have you stop driving your SUV and drive an electric car? Is this enough for you to strive to stop buying and using material which when manufactured generates more carbon-dioxide and use the more expensive or inconvenient alternatives?

The mega-mammals (i.e. sloths, mammoths, saber-tooth tigers, etc.) once super-populated the world and are now extinct. Humanity only flourished because of our adaptability and creative inventions. Now our inventions are pushing CO2 levels up. It is time to adapt or die. No sense in arguing. What actions will you take and who else can you convince to join you? If you don't believe then just live your life accordingly. Those who believe will need to do what they can based on their beliefs. Arguing does nothing. Convincing others can change their actions.

Answer 12

What I find interesting is that I talked about the fact I saw a cooling trend happening and now someone you trust and admire in a round about way confirmed it. I think it will be interesting to see what happens in the next few years. So if the next seven years are consistently colder like I predicted and now Hansen also predicted, it might be hard to keep people believing in this theory. And if it's even longer than seven years you possibly will lose everyone that believed in it.

So if scientists are concerned about CO2 levels rising in our atmosphere maybe they should have picked a better approach then this thoery to get people on board with the idea of reducing human output of CO2.

I'm talking about human memory and how susceptable it is to shoving something aside when enough time goes by to make it a non-issue to them. Especially, if it starts getting obviously colder in the next few years.

Answer 13

Time will tell.    

Answer 14

Before I can answer, I would have to know who "those who argue" are. I happen to find Dr. Hansen very credible. My point is, I would like to know who is promoting global cooling when the temperature graphs don't support it.

Please, skeptics or deniers, enlighten us.

Dana - thanks for the info...I still find Dr. Hansen very credible, along with all the rest of the mainstream scientific organizations who agree warming is in our future with the rising greenhouse gas concentrations. Global cooling is a Red Herring. Global Warming has been happening for decades and is irrefutable,

http://data.giss.nasa.gov/gistemp/graphs...

while 2007/2008 has been a little cooler than the past 10 years, but still warmer than the mean, and the deniers are yelling "COOLING, COOLING..."

Answer 15

Natural causes can overide the effect of CO2.  This is on a yearly/decade phase.  Historical evidence suggests that the sun/other factors can have a larger impact over 20-30 year period.  1860-1880 .2 deg C ~ .6-1 W/m^2.  1880-1905 - .25 deg C or -.9- -1.3 W/m^2.  From 1905-1940 +.3 dec C ~ 1.1-1.3 W/m^2.  CO2 at this time could only be responsible for .2 W/m^2.  Given our temperature chart the natural varience for our temperature is about +/- 1 W/^m^2.  I would say from historical data he is understamating natural effects.

The key is the feedbacks.  All of the feedbacks are tied to temperature and not CO2.  As the natural causes cool the earth, the feedbacks are turned toward cooling.  Lets say we have a .25 degree temperature drop natural, carbon forces to .2 degree.  According to some models the feedbacks will be 2-3 times the source. This could lead to a -.6 degree drop or a feedback nuetral CO2 rise.  For that matter,

Why can't the recorded natural .2-.25 degree C  rise prior to 1940 be responsible for the .6 deg C rise?  the ratio is the same.

I do not believe a .2 deg C rise can lead to a .6 degree rise, but according to feedback thoery it could.  I am more pointing out flaws in the feedback theories.

Also the models sometimes show cooling or an ice age, those are thrown out as noise.  I am not a believer in the models.