Thanks very much for providing the article. To quote from the discussion section:

"We are left with the least unlikely hypothesis that the gradual erosion is produced by dust devils, perhaps concentrating rather than removing the dust. "

There is no mention of newly exposed mineral deposits being eroded and distributed, etc.

While I will concede that there exists the possibility of some other mechanism for an increase in dust deposits (via dust devils), until someone can provide a more logical explanation, I can only assume it was due to increased wind activity.

If there was increased wind activity, then I can only assume it was due to more energy input into the Martian climate.

If there was no sudden volcanic activity, significant increase in meteor strikes, or other reason for this increase in energy input, then I can only assume that it came from the sun... After all, the increase in energy has to come from *somewhere*.

Also, public consensus on science is hardly a wise thing to base policy on - And scientists themselves have held wildly erroneous ideas up as "consensus" (e.g. the sun was thought in the 1800's to be fueled by coal), many do so until there is no way to defend their position without seeming ridiculous.

Again, we may have to agree to disagree (at least until more is known).

Googling Paul E. Geisler produced this:

http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2190.pdf

The article talks about specific regions of the planet and various reasons for changing albedo. The winds are variable and more or less circumferential, and there is no mention of darkening the poles due to dust. There is mention of polar darkening due to some melting/sublimating of CO₂ ice.

In other words, the warming of Mars argument seems to be no more reason to deny anthropogenic global warming than is the old saw about global cooling in the 1970s.

Fred Bortz
Science and technology books for young readers (www.fredbortz.com)
and Science book reviews (www.scienceshelf.com)

Dave,

Thanks for the comments and the reference to the global "theory du jour," which had nowhere near the level of support (or the detailed climate modeling now available) as the current consensus. It is one of the classic, discredited arguments of the political denialists. The scientific skeptics have long since stopped citing it.

In fact, we now know that the 1970s cooling was an effect of increased particulates in the atmosphere due to burning of fossil fuels. (See "The Weather Makers" by Tim Flannery for an interesting discussion of this.) Cleaning up the powerplants removed the masking effect of the particulates and allowed greenhouse gases to have their effect without abatement.

I'd have to dig out my New Scientist article and then trace that to Geissler's journal article to be sure, but I was left with the distinct impression that the changes in albedo were primarily from the main body of the planet and not the poles. Such changes could (and do) go either way, depending on the dust distribution. The article did not mention dust on the poles or increased winds, just a redistribution of dust that happened to produce a darker Mars.

Anyway, the place to settle the argument is in the original Geissler article. Perhaps someone can chime in with the relevant paragraphs or the abstract.

Fred Bortz
Science and technology books for young readers (www.fredbortz.com)
and Science book reviews (www.scienceshelf.com)

(Apologies for my previous "Anonymous" comment. That was me.)

I realize we may have to agree to disagree on this issue, since we seem to be unable to come to an agreement on cause/effect.

While I accept that it is theoretically possible that there is some other, unexplained mechanism for the reduction in Mars' albedo reflectivity, the most logical culprit is be increased dust storm activity - Which would deposit more dust everywhere, including the poles, obscuring the light colored polar regions.

The only logical cause for increased dust storm activity is increased solar irradiance.

Unless someone can point to a large, soft mineral deposit on Mars that was suddenly exposed to wind erosion; and has been subsequently rapidly eroding over the past decades (thus "injecting" a tremendous amount of dark dust into the Martian atmosphere, causing a reduction in albedo without an increase in dust storms), I will remain unconvinced that the increase in Mars' temperature is due to anything else other than increased solar irradiance.

Interestingly, the theory du jour of 1975 was global cooling: http://denisdutton.com/cooling_world.htm

One of the supposed remedies for this was to coat the polar ice caps with soot to decrease the Earth's albedo.

There is nothing in the original post about changes in the amount of dust that is blowing around on Mars. I'm sure that varies quite a bit, as do the intensities of Martian windstorms.

The issue here is the changes in distribution of that dust from time to time. In this case, more dark surface has been revealed, which leads to some warming. At other times, the dust distribution causes the surface to be brighter, which leads to some cooling.

It is indeed a stretch to conclude that the uncovering of more dark material is anything more than a chance event, no matter how strong the winds happen to be.

Fred Bortz
Science and technology books for young readers (www.fredbortz.com)
and Science book reviews (www.scienceshelf.com)

Fred, you seem like a pretty logical guy... So I'm frankly puzzled as to why you you term it as "quite a stretch" that an increase in solar irradiance would result in an increase in dust clouds (storms) on Mars.

Atmospheric movement on any planet results from mainly two things: The planet's rotation, and the amount of sunlight incident on it - The "engine" that drives atmospheric activity.

If there is a reduction in the planet's albedo over the given time frame due to dust, than that can only be because there was an *increase* in dust. It doesn't matter that the article doesn't specifically state why there is more dust now, the list of possible culprits is short.

If Mars is experiencing greater atmospheric movement (resulting in more dust storms), then the only logical culprit is increased sunlight, given the fact that Mars' rotational speed is stable and that it hasn't experienced any catastrophic volcanic eruptions or a significant increase in meteor impacts.

Actually, the article doesn't say whether more or less dust is blowing. The point is that, perhaps by chance, the net result of the blowing dust is a decrease in the planet's average albedo over that time frame, which results in a warmer planet. Attributing that to changes in solar radiation is a real stretch.

Fred Bortz
Science and technology books for young readers
and Science book reviews

Perhaps increased thermal activity due to... Increased solar irradiance?!

Anybody else want to offer a plausible theory as to why there's more wind on Mars? Because that's the most logical one *I* can come up with.

Skeptic, I don't buy your premise that the basic science has not been done. You apparently would like to see different research and you may have a different definition of "basic" than most climate researchers.

But, more importantly, I think you missed the point of my posting, and I'd like to direct the discussion in that direction.

I'm looking at this in terms of the grassroots community efforts that I am getting involved with and have discussed earlier in the blog. One of the biggest obstacles to the discussion are people who get their "science" from politicians like Inhofe (sorry for the earlier misspelling). They refuse to read books like those I have been reviewing for ten years, but claim to "know" that our recent warming is due to changes in solar radiation.

They point to recent warming on Mars as evidence, but the article I described provides a better explanation for Martian warming.

We need scientific skepticism to keep us honest, but I would like to quote an editorial in the 14 April 2007 New Scientist regarding funding:

Assuming there is no "groupthink" here, or a global scientific conspiracy, the only other occasionally voiced argument is that IPCC scientists have staked so much on greenhouse gases that they are unwilling to brook any alternative. This notion runs so completely counter to what science is about that it is as likely as a global conspiracy.

I reject your claims about conspiracy and your argument about funding, and I see no point in discussing that further. It will degenerate into a pointless "'Tis-true, Ain't-so" non-conversation.

As for "groupthink," I value skeptics precisely because they keep a consensus from becoming a bandwagon. Continue to be skeptical on scientific grounds, but please drop the conspiracy theories and the arguments that scientists need certain results to keep their funding.

At this point, I will drop out of the discussion and let others chime in. I would be particularly interested to hear about other people's experiences in trying to get the nonscientific public to understand the scientific issues and the consequences of inaction on this issue.

Fred Bortz
Science and technology books for young readers and
Science book reviews

Thanks for your reply. I am a SKEPTIC because the basic science has not been done. Here is why.

1) The only way for earth to warm is for the generated and received heat to exceed that radiated to space. It does not matter how much CO2 is in the atmosphere or any other factor. Only an excess of energy remaining within the atmosphere can generate warming period.

2) I will make up my mind when the energy budget has been demonstrated. We have the resources to do this.It is a very simple equation that leaves no doubt and is provable and repeatable. The hallmarks of good science. Instead of speculation and computer models, just take the measurements and find out the facts. The physics is simple.

3) Whenever I hear people chanting a mantra that sounds a lot like religion rather than science, I think of them just like the used car salesman. They are trying to pull something. So until I see real scientists doing real science backed by real facts and repeatable experiments, I will continue to be skeptical.

I'm sorry but those emminent scientists Al Gore, Knute Gingrich, and Imhofe (all politicians) have exactly nothing to say that I care to hear. They not only have no standing, but I doubt seriously they they want anything but more power and money.

It is a sorry state of affairs when scientists must pursue grant money with strings attached. Grant proposals always begin with a premise..."I'm going to prove xyz" not "I'm going to investigate xyz and find out what it means". Which agency is going to give out money for that? Certainly not the EPA, or DOE, or any other agency I can think of. They all have their own agenda and the funding is carefully doled out to those who can advance that agenda. It is not a conspiracy, just human nature. Would you give money to someone diametrically opposed to your views? Or even someone who did not agree at least in part with your thinking? I think not. Yet that is exactly what science demands. Skepticism. Always question your results. Always try to prove yourself wrong. You can never prove a thing true, you can only disprove it. That's why they are called theories. Even the old "Laws" have succumbed many now relegated to the status of theory but still used because in the macroscopic world they still suffice to explain things while in the world of the ultra small (quantum world) they no longer work.

Yes, I want to see the science. Because popular causes and political agendas scare me. these people hop on the bandwagon because they see some gain either power over me and you or money or both. It is almost certainly gauranteed that it is not altruism.

I am a skeptic, but I am persuaded by what I have seen to accept the IPCC consensus, which states that global warming is real and that it is, to a high degree of likelihood, caused primarily by human activity.

That consensus has plenty of "real science" behind it, and it has determined that "warming is real and not a myth perpertrated by those in need of grant money." The big money interests in oil and coal have reason to wish it were not so, whereas scientists can get grant money to study the climate regardless of where their conclusions lead.

When I use the term denialist, I am not speaking about other skeptics who ask for more evidence before accepting the consensus. I am speaking of the people who seize on any argument they can to dispute the IPCC consensus and who claim there is a vast conspiracy among grant-seeking scientists.

I am speaking of people like Senator Imhofe, who continues to call the idea of anthropogenic global warming (AGW) a hoax. If that describes you, and your language suggests it does, then I make no apology for calling you a denialist, not a skeptic. If that offends you, then pehaps you are too easily offended.

Fred Bortz
Author of science and technology books for young readers and
Science book reviewer

First, the use of perjorative terms for people who disagree with you is insulting and hardly worthy of a "scientist". The word is SKEPTIC. and there are many of us. First, the science has NOT been done. What we have are a lot of theories and models but absolutely nothing by way of real science. What is demonstrated is that ice is melting in various places. Whether this is due to changes in weather patterns or true warming is still open to debate,

Next, there still have been no widely published and distributed studies of the global energy budget.. There is one way and one way only for global warming to be a fact. That is for the earth to receive and retain more heat than it radiates to space. We have sufficient assets in space to determine the radiated energy, we can certainly calculate the total energy received from the sun as well as that generated by human activity and heat transfer due to natural radioactivity and conduction through the mantle. So where are the energy budget figures? Inquiring minds want to know. The source of warming if it exists is immaterial at this time. What is needed is some real science to determine if warming is real and not a myth perpertrated by those in need of grant money.