Global Warming: NASA photo of Earth taken from Apollo 17
Global Warming: NASA photo of Earth taken from Apollo 17

Have you been following the comments in Cari's Buzz Blog post about Gore's movie, An Inconvenient Truth. I find it interesting that very intelligent people can look at the same data ("truths") and yet totally disagree as to what to accept as reality?

A Global Warming Skeptic Challenge

George Musser on the Scientific American Blog has been moderating a discussion about global warming titled Are You a Global Warming Skeptic? Part IV He started the discussion March 6, 2006 with this statement:

In the comments field, explain which aspects of climate change you don't accept (e.g. you might not think Earth is warming at all, you might not think the warming is due to greenhouse gases, you might not think that the gases are produced by humans, or you might not think warming will cause trouble in the future), what exactly has led you to this conclusion, and -- most important -- what it would take to convince you otherwise. Let's get everything out into the open, so that we can have a real discussion.

The discussion is presented in four parts with hundreds of comments. I am recommending this thread because Musser first listens to, then presents a summary of the skeptics' arguments. I find the fairest way to make up my mind on an issue is to thoroughly understand both sides of the argument. Musser explains how scientists crunch the various data to answer difficult questions. He uses the analogy of examining fingerprints during a crime scene investigation.

Climatologists have maps and time series showing how a boatload of climate variables -- mean temperature, temperature ranges, air pressure, precipitation, and so on -- vary in time and in space, horizontally across the surface and vertically through the atmosphere. These data sets are a gold mine for resolving ambiguity, because the different forcings leave distinct fingerprints. Such patterns make it possible to tease out their relative contributions. Over the years, researchers have considered ever more variables besides temperature and ever more forcings besides greenhouse gases. They have merged spatial and temporal patterns, looked at regional as well as global scales, and developed more sophisticated mathematical tools.

View from the Crime Scene

"Fingerprints" included solar variability, volcanic eruptions, greenhouse gasses, ozone, aeosols, and various generic effects. When climatologists run the fingerprinting analysis for different historical epochs, they find that temperature fluctuations prior to the Industrial Revolution were driven primarily by solar and volcanic forcings. In the early 20th century, natural and anthropogenic forcings seem to contribute equally. From midcentury onwards, greenhouse gases rule(temporal pattern). Since 1979, when continuous satellites observations began, the surface and troposphere have warmed and the stratosphere has cooled(vertical pattern). Pretty much the entire surface has gotten warmer, high latitudes more than lower ones(horizontal pattern). All the oceans have warmed; there isn't the zero-sum game of warming and cooling you'd expect from natural variability(energy variability).

Musser concludes,

"unless I'm missing something, it seems to me that the case for anthropogenic warming is pretty strong...Based on the knowledge we have so far, however, I have to call 'em as I see 'em."

To appreciate the use of critical thinking and scientific method I recommend wading through the four installments of "Are you a global warming skeptic?" Part I (673 words); Part II (2219 words); Part III (2617 words); Part IV (3516 words); and an Appendix

Your Comments, Thoughts, Questions, Ideas

Gene's picture
Gene says:

As The Science Museum’s resident Global Warming skeptic, I feel an obligation to weigh in here. ;-)

I welcome Mr. Musser's approach. It's refreshing to have someone so willing to listen to all sides. However, it is said that the best way to win an argument is to know your opponent’s position better than he knows it himself. And in this, Mr. Musser fails. He presents his argument, assuming that the reason people are skeptical about Global Warming is because they do not understand some part of it. But that’s not it at all. I agree with and accept all four of his aspects (well, three-and-a-half, anyway), and am still dubious about Global Warming.

Let me back up a second and define some terms. By “Global Warming” (capital letters), I refer to what might termed the standard hypothesis: the series of cause-and-effect that is presented by environmentalists such as Al Gore. It goes something like this:

· Human beings pump a lot of carbon dioxide (CO2) into the atmosphere.
· CO2 is a “greenhouse gas” – it retains heat.
· This heat warms the globe.
· This warming will have a serious – perhaps dire – impact on the environment, and all life on Earth.

Which leads to two inescapable conclusions:

· Human action is causing global warming
· Human action – and only human action – can stop it.

Neat and tidy argument, no? Connects all the dots.

Well, no, it doesn’t. There are numerous dots that don’t fit this pattern. In fact, there are two huge ones that cast this whole hypothesis into doubt:

= = =

1. Climate is complicated. There are so many factors, so poorly understood, that it is virtually impossible to make direct cause-and-effect assertions. In fact, back in the ’80s, climate was the poster child for the new field of complexity studies (a.k.a. Chaos Theory). There are systems so sensitive to initial conditions that if you change just one variable by a tiny, imperceptible amount, it will set the whole system running off in a different direction. And – here’s the kicker – that direction cannot be predicted. Climate is just such a system. Pete DuPont, former governor of Delaware and chair of the National Center for Policy Analysis (a political think-tank) notes:

“There are substantial differences in climate models--some 30 of them looked at by the United Nations Intergovernmental Panel on Climate Change--but the Climate Science study concludes that ‘computer models consistently project a rise in temperatures over the past century that is more than twice as high as the measured increase.’ "

In other words, climate scientists come up with theories as to how climate works. They test those theories against actual climate data, and the theories are way off. Clearly, we do not know enough about climate to know how much effect humans are having, and how the climate may change in the future.

2. Climate is dynamic. The Earth’s climate has always changed. I’m not just talking about Ice Ages. Even during historic times, global temperatures have fluctuated more greatly than what we are seeing now. 2,200 years ago Europe was so warm that the Alps were glacier-free. Clearly, this was not due to gas-powered engines or coal-burning factories! Later temperatures dropped, but rose again around 1100 – the Medieval Warming Period, which allowed the Vikings to colonize Greenland and reach America. Temperatures cooled off again around 1600, the onset of the Little Ice Age. Again, this was purely natural, and not caused by a change in human consumption patterns.

More recently, global temperatures rose from about 1890 to 1940; leveled off or even fell slightly; then began rising again from 1980 to 1998. (They’ve been holding fairly steady since.) Heck, there is even global warming on Mars! All of which leads Richard Lindzen, MIT Professor of Atmospheric Science, to argue that the human impact on global temperatures is unknowable. Whatever effect we may be creating, it remains within the range of ups and downs the Earth has been going through since long before the Industrial Revolution.

= = =

So I in fact agree with all four of Mr. Musser’s points. Yes, the Earth is warming – no doubt about it. Yes, no question, humans are pumping tons of CO2 into the atmosphere. Yes, CO2 is a “greenhouse gas,” though there seems to be some debate over just how strong a factor it is. And yes, changing global temperatures will have some impact on the environment. (Though this is where I start to veer off – my “half-agreement.” No one can say what the impact, if any, might be, or even if it will be bad. As Yogi Berra famously said, it’s difficult to make predictions about anything, especially the future).

But there’s more to the debate than just those four tidy points. And the pieces he leaves out are the very pieces which call the standard hypothesis into question.

It is definitely possible that human beings are indeed the cause of the recent warming. But that has not been proven. Until it is, any proposed changes in human activity would be an attempt to cure a problem that may not exist. And since some of those “cures” could drastically reduce the quality of life for billions of people around the globe, it’s best to go slow on the more radical proposals. After all, people have been predicting the end of the world ever since shortly after the world began. And they haven’t been right yet.

posted on Mon, 07/10/2006 - 12:18pm
ARTiFactor's picture
ARTiFactor says:

I appreciate the time and thought that goes into your comments, Gene. I feel readers should be presented more than just one side of this debate. Being a global warming sceptic can also earn you a couple hundred thousand dollars!

Pat Michaels, a global warming sceptic, will soon be reimbursed for his efforts. The Intermountain Rural Electric Association, or IREA, of Sedalia, Colorado, gave Michaels $100,000 and started the fund-raising drive, said Stanley Lewandowski, IREA's general manager. He said one company planned to give $50,000 and a third plans to give Michaels money next year.
Frank O'Donnell, president of Clean Air Watch, a Washington advocacy group, said: "This is a classic case of industry buying science to back up its anti-environmental agenda." Read more at: Wired Tech News

posted on Fri, 07/28/2006 - 1:01pm
Gene's picture
Gene says:

Obviously I am in the wrong business! ;-)

posted on Mon, 08/14/2006 - 2:04pm
Anonymous's picture
Anonymous says:

I agree with Gene. The pollution is one many factors, and not
as major as people think.

posted on Tue, 07/11/2006 - 10:26am
Madhatter's picture
Madhatter says:

I have heard that we are coming out off a mini ice age so the place is going to get a little warmer. I also thaink that maybe evey so millon the planet gets warmer and noboby wrote down what happened all those years ago.

posted on Tue, 07/11/2006 - 10:27am
Anonymous's picture
Anonymous says:

I think that if the world warms up, then the ice will melt and cool off the Earth again.

posted on Thu, 08/10/2006 - 4:55pm
ARTiFactor's picture
ARTiFactor says:

I see in today's news that the melting is speeding up. I hope your logic is correct.

Greenland's ice sheet is melting three times faster than two years ago, according to satellite data.

source; BBC News

posted on Fri, 08/11/2006 - 8:57am
Jennifer's picture
Jennifer says:

The earth is getting warmer and that just plain scares me. We are going to be having creatures living here in minnesota that are dangerous and could pose a potential life threat. I hope we are able to slow this warming trend in order to preserve the earth as long as we are able.

posted on Fri, 08/11/2006 - 10:20am
Anonymous's picture
Anonymous says:

the earth goes through a natural cycle... everything will be fine!

posted on Fri, 08/11/2006 - 3:58pm
Anonymous's picture
Anonymous says:

I believe that global warming is true, and that we should be worried about it.If you have any doubt, go and see the movie An Inconvenient Truth!

posted on Sat, 08/12/2006 - 3:09pm
Gene's picture
Gene says:

There is another thread on this site which discusses that movie.

posted on Mon, 08/14/2006 - 2:07pm
Arash's picture
Arash says:

I agree completely with what you say. Lately, our planet has been turning in for the worst-increased numbers of hurricanes and rapid melting of our glaciers-and I believe that this is due to global warming. As technology progresses and humans advance in knowledge, machines are used more frequently and feverishly to complete tasks that were once accomplished by hand. This results in a drastic increase in the amount of pollution earth must endure, creating a hole in the o-zone andallowing UV rays to wreak havoc upon us. If we plan to live on our planet for as long as we anticipate, it is time to join in the cause to fight excess amounts of pollution destoying our world.

posted on Sun, 08/13/2006 - 1:29pm
Gene's picture
Gene says:

Hurricans follow a multi-decade cycle that does not seem to respond to changes in global temperatures.

Temperatures rose from 1980 to 1998. But during the '90s, the number of large hurricanes was very low. Temperatures then stablized, and even dropped a tiny fraction in 2005. But hurricanes did not increase until last year. Thus, it seems there is little connection between rising temperatures and the number of hurricanes.

posted on Mon, 08/14/2006 - 2:10pm
Chris E's picture
Chris E says:

As a mechanical engineer I see one major point that no one seems to be hitting on. What is the uncertainty in the temperature measurments that have been recorded and compiled to make this broad picture that shows the earth's temperature rising out of control??

Look at the temperature changes we are talking about, merely tenths of a degree. Then consider what the uncertainty of a temperature measuring device is, maybe +/- 1 degree. This is especially true for historic records. Therefore if you were to put error bars on any of the graphs used to prove (or disprove) global warming I think you would see the trend would in fact level out.

Also, one needs to consider things like basic fluid mechanics...
It is extremely difficult to calculate with a very high degree of certainty the ayerodynamic effect of a fluid moving over an object that is anything more complicated that a cylinder in cross-flow. Most of the involved variables are based on empirical experiments because and analytical solution is impossible with our current understanding of the world.

Now try to put that into a global perspective, and it is very easy to see how incredibly hard it is to predict climate and even weather. You are Incredibly nieve to think that any current model of our climate (especially one that tries to predict the future) is anything more that a gross approximation.

This is not to say we should ignore the enviroment and polute it as if there is no consequence.

I am not claiming to be a climate expert, because I am not. In my arguments I only applied the basic knowledge taught in any engineering program.

posted on Thu, 08/17/2006 - 2:18pm
argh people's picture
argh people says:

Global Warming is just a weather cycle! A WEATHER CYCLE! Take the last ice age for example. Was that not a weather cycle too? I'm sure it was. These things happen, and I don't think humans have even effected it.

posted on Mon, 09/11/2006 - 8:00pm
ARTiFactor's picture
ARTiFactor says:

Here are two recent articles about skeptical politician Inhofe:

posted on Sat, 09/30/2006 - 9:53am
Anonymous's picture
Anonymous says:

The earth is fine and can repair itself.
Look at cities like Pittsburgh and Cleveland. Look at how bad London used to be with pollution. They have been cleaned up.
It is all a cycle.
We had warming back in previous years also, even back when there were no vehichles of any sorts. So how could that be.
Like the medical field, there is big money in the "global warming" fear and that is why it must continue.
They tell you a bird flu is coming and to get your shot. Where is it?
The flu shot contains mercury! Last time I checked, mercury is bad for you.
They treat cancer with radiation, which causes cancer!
It is all about money.
Global warming is not happening.
It has been record low temps where I live. Something that would not happen if the earth were warm.
Have you been in a greenhouse before?
The temp inside is THE SAME throughout the whole greenhouse. Not so with our earth.
So go on, worry about it if you want, change your lifestyle. I WILL NOT!!!!!!
Support National Industrial Revolution Day!

posted on Wed, 02/21/2007 - 8:38pm
Anonymous's picture
Anonymous says:

Actually I started to look at the cause for global warming by looking at the data. Here are my result. There are much talking but how many of you actually look at the data of competing theories.

posted on Thu, 03/01/2007 - 11:49am
Rock Chick's picture
Rock Chick says:

I am worried about Antarctica. Global warming is a problem and the ozone layer. Wow! It's shocking. Just think of how it will end up in 50 years time. There will be nothing.

posted on Fri, 03/23/2007 - 11:02pm
mentor's picture
mentor says:

can we create or invent some sort of filter that can reduce the amount of carbon dioxide that a car gives off? I mean a filter similar to a house filter. Because a house filter can reduce dirt and bacteria so why can there be filters in the exhaust pipe of a car to trap some of the methane or carbon dioxide given off from the car? Just curious!

posted on Thu, 11/15/2007 - 4:05pm
mentor's picture
mentor says:

Not only a filter, could they make a gas that neutralize carbon dioxide? Is there any kind of way we can make a gas like that? If so can the attach them to a car like an exhaust pipe? So when cars shoot out all that unwanted carbon into the air the other pipe can shoot out a neutralizing gas that neutralize the fumes.

posted on Thu, 11/15/2007 - 4:22pm

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