Global Warming and tell tale leafs

[pattylou]

The oceans have been cooling a bit in the last two years for instance.

Yes, it is my understanding that the oceans cycle warm/cold every 25 years, and that the dip in global temps ca 1948-1973 were precisely correlated with a cooling trend in the oceans. The current cooling trend is right on schedule. The question is whether long term warming is occurring when you take this cycle out of the equation, and the answer appears to be yes.

Ice shelfs break off continuously. Nothing "distressing" with that.

I assume you have seen satellite imagery over the northern polar region comparing ice today, vs 10 years ago.

Ex: Here is Greenland, 1992 vs. 2002:

http://usinfo.state.gov/gi/img/assets/4475/110804climate.jpg

(not sure if I linked that right, click on the link otherwise.)

I disagree that there is "nothing distressing" here.

There is sufficient evidence in the ODP sediment cores to suggest that the Antarctic ice sheet is bigger as it ever has been, including in the "ice ages". So we have a lot of statements but even about the ones that are true, we still don't know if it is relevant, if we can exclude CO2 as main climate forcing driver.

Not much to say here, except that "global warming" has been replaced with "global climate change" because it has become obvious that some areas are cooler, due to changes in ocean currents and so on. Still, my understanding is that within Antarctica, there are regions of serious melting, resulting in loss of krill and threats to the species (whales) that feed on the krill.

Actually, can you reference that the Antarctic Ice Sheet is not melting? I just spent ten minutes on google, and couldn't find much to sipport youir claim. As a last ditch effort to get a feel for the accuracy of your statement, I did the following experiment:

Google: Antarctic ice sheet climate change "is melting" (7000 hits)

Google: Antarctic ice sheet climate change "is not melting" (90 hits)

So a reference would be useful, I'll add it to my list of reading.

It may very well be that the climate change is partly anthropogenic but it is also very possible that the main forcing is not CO2 but for instance high altitude waper vapor produced by jet aircraft or soot or other factors and it would be an ethernal shame if we wasted the Kyoto assets on something that was innocent in the first place. And then again, where is the catastrophic part coming in?

Yes, that may be possible, see my comments on "precautionary," previous post. The catastrophic part? Depends on your POV. I think the loss of species on a daily basis is catastrophic. In other words, we're witnessing it. I think the rise in sea level that is predicted, will be catastrophic. The recent weather patterns (changes in hurricane intensity, etc) may not be due to climate change - but if they are, as is occasiionlly suggested, that is clearly catastrophic. Europe may cool significantly in the next decades, as warm water from the gulf (I think?) no longer travels up the conveyor to warm Europe.

There are predictions that the third world will be least able to cope with a changing climate, and will be hit hardest economically. This is catastrophic, especially as we are fighting so hard to improve health and education in the third world, as the planet's population is near to bursting.

More catastrophe in the news:

A startling scientific study last week revealed that Bangladesh’s biggest island, Bhola, had been shrunk to half its size over the past 40 years by rising waters, making half a million people homeless.

from http://www.sundayherald.com/50323

But some people hold, and this is reasonable after a fashion, that none of the above is catastrophic. Some people hold that life is never static, and change is fine, and even good. If the population crashes, really nothing is lost. We just start over. To these people, then, there will be no catastrophe. Depends on your point of view.

 

[reasonmclucus]

Wow, is everyone here really poopooing (or pooh-pooh-ing) anthropogenic CO2 causing global climate change?

I'd be curious for your qualifications, as there is broad consensus in the scientific community that our CO2 output is directly related to a warming planet.

My initial assumption is that this forum has a good representation of scientists participating - and so the tone of this thread surprises me!

(Tony, you have done some good things in your country wrt climate change; I am surprised to learn that you are a climate change skeptic and one that mis-spells, at that! ;) )

A warming climate causes CO2 increases by encouraging biological activity. If there were any real science behind the idea that CO2 could cause warming there wouldn't be so much interest in trying to find past "evidence" that it can do so.

If CO2 can heat the atmosphere, scientists should be able to use experiments and math to show that CO2 which is a mere 1/2800th of the atmosphere can somehow absorb enough extra heat energy from the process of absorbing than then reemitting a very narrow band of Infrared radiation(IR) to heat the remaining atmosphere. The process of absorbing specific wavelengths of radiation requires a molecule to release radiation of the same wavelength before it can absorb more radiation which means any energy converted to heat would have to come from the difference in the energy absorbed and the energy released. An additional factor is that thermal physics states each conversion of energy produces an very small amount assigned to entropy which is energy that is essentially lost to the system and doesn't cause heating.

To oversimplify the math, each gram of CO2 would need to generate 2,800 times the amount of heat needed to heat it in order to heat the rest of the atmosphere. About 700 calories of heat per gram would be required to raise the temperature of 2,800 grams of air by 1 degree C. An added problem is that 66% of Earth's surface is covered by water which is a very poor radiator.


The water vapor produced by combustion of hydrogen containing fuels is more likely to have an impact on atmospheric temperatures. Water vapor releases 540 calories of heat per gram when it condenses to its liguid state. This would be sufficient heat to raise the temperature of over 2 kg of air by 1 degree C.

I noticed the post immediately above after I posted this so I'll add something on Antarctica. The whole issue about what is happening there has become somewhat amusing because it seems at time that studies alternate between saying that the continent is becoming warmer and that it is becoming cooler.

Warming in the area of the Antartic Peninsula and the Larson B ice shelf may be related to the local factor of an undersea volcano in the area.

http://www.sciencedaily.com/releases/2004/05/040527235943.htm

the volcano could send heated water to the bottom of floating ice causing it to melt. Water will melt ice faster than air because water has a coefficient of heat about 4 times that of air meaning more air, which is also less dense than water, is needed to melt ice. A volcano would also heat the water in contact with it higher than normal air temperatures.

 

[reasonmclucus]

I mentioned the scientific method because of features like reproducibility, and peer review - which although not part of the method per se, are part of science in general. Because science proceeds in this measured way, always checking itself, consensus is a good thing. It indicates that a lot of independent work is reaching conclusoins along the same lines.

The peer review process has a serious weakness in that it can discourage publication of articles by those who challenge what John Kenneth Galbraith once described as "the conventional wisdom". Funding also complicates the process. Much funding for climate research comes from government which prefers nice simple explanations that politicians can understand. Governments have tended to favor those researchers who at least give lip service to the idea that climate is a simple process that humans can affect by the changing the amount of CO2 in the atmosphere.

Traditional science has dealt with relatively simple processes that can be easily modeled mathematically even though the equations may be very complex. The environment, including climate, tends to be very complex with interaction affects that are difficult to model. The study of weather/climate played a major role in the development of the new math/science of chaos theory.

One of my concerns about the whole greenhouse gas theory is that it attempts to provide a simple explanation for something that is extremely complex. The climate at anyone time depends on how various cycles interact or coincide. For example, the amount of energy the Earth receives from the sun varies constantly depending on variations in solar energy output and Earth's distance from the sun including variations in the shape of the Earth's orbit which can vary from nearly circular to various ellipses. Earth is currently closest to the sun during the northern winter which means less freezing weather and possibly a reduction in areas covered by ice. Earth is farthest from the sun right now.

The following site provides some diagrams of the Milankovich cycles.

http://www.homepage.montana.edu/~geol445/hyperglac/time1/milankov.htm

 

[Pengwuino]

Sorry to jump off topic but how does hte peer review process work for journals? Can you just say "no i don't like this" or do you need to provide real factual explanations in order for your review to be accepted?

 

[pattylou]

Sorry to jump off topic but how does hte peer review process work for journals? Can you just say "no i don't like this" or do you need to provide real factual explanations in order for your review to be accepted?

Typically, an article is submitted to a journal, and the editor sends it out to three other researchers in the field.

Those researchers each critique the methods and logic in your paper - so you get back the critiques and they generally say something like "Such-and-such additional control should be done," or "Work by So-and-so has countered claim X and this should be addressed in the discussion," or some other tangible piece of constructive criticism. Occasionally, additional entire sets of experiments need to be done based on the reviewers feedback, before the paper can be re-submitted, and the paper can be held up for a few months as a result.

You incorporate the recommended changes to the paper, or explain why you don't think a particular change needs to made (sometimes the reviewers are wrong), and then re-submit. The quality of peer-revewed journal articles is higher as a result of this process.

It should be fine to questions "conventional wisdom." In fact, if you author such a paper and are aware of hostile researchers in the field, you can ask that some particular researchers not be a reveiwer.

But if you challenge conventional wisdom by making unfounded assumptions or some such bad form, the review process will catch it.

 

[pattylou]

A warming climate causes CO2 increases by encouraging biological activity. If there were any real science behind the idea that CO2 could cause warming there wouldn't be so much interest in trying to find past "evidence" that it can do so.

I'm not sure that your premise here is correct. Plant and algal biomass outstrips fungal and animal biomass. A warming planet (within the ranges we currently see) could allow greater carbon fixation.

In my understanding, the reason we are seeing the plants not keep up with our CO2 production, is because of the sheer amounts that we are making.

And a note to Andre': Another "catastrophe" is that the surface waters in the ocean are becoming very slightly more acidic as CO2 levels in the oceans increase. The drop in pH so far, due to CO2, is about 0.1 pH units, which is slight but may affect biological marine activity, particularly of the marine microorganisms. If the atmospheric CO2 ppm continue to increase, to 500 or 600 or 700 ppm, we may expect to see dissolved CO2 in the oceans continue to increase, and the pH continue to drop. How much acidity can the oceans sustain? Is a drop of 0.5 pH units alarming? To me, yes.

edit: Sorry, change "sustain" in the last paragraph, to "tolerate." (Hadn't had coffee yet. Home roasted beans from Sweet Maria's, home ground, home espresso'd. Yum. Starbuck's can't touch this.)

 

[Andre]

Sorry, there are several small misconceptions with that idea. Unfortunately I'm high in the overload mode for the remainder of this week, So I need a few days, but I'll be back with a lot of details why all those catastrophies are slippery slopes.

 

[pattylou]

Thanks Andre,

Take your time. If you have the ice sheet reference at that point, I'd appreciate it, as well.

 

[matthyaouw]

Woah, I go away for a couple of weeks and all this springs up. Its certainly going to take me a while to read through all this properly.

I assume you have seen satellite imagery over the northern polar region comparing ice today, vs 10 years ago.

Ex: Here is Greenland, 1992 vs. 2002:

http://usinfo.state.gov/gi/img/assets/4475/110804climate.jpg

(not sure if I linked that right, click on the link otherwise.)

Could you tell me what the red/orange areas represent? There seems to be no key.

I'm not sure that your premise here is correct. Plant and algal biomass outstrips fungal and animal biomass. A warming planet (within the ranges we currently see) could allow greater carbon fixation.

I too thought this when I read it, but just to put forward another view, perhaps increased global temperatures could lead to increased cloud cover, reducing the amount of light plants recieve, leading to less carbon fixation. (I'm merely speculating here, so don't pay too much attention to this.)

 

[pattylou]

Could you tell me what the red/orange areas represent? There seems to be no key.

If I recall, the red/orange shows the much greater land exposure today, compared to ten years ago. THe white area is still covered by snow (ice?) but the melt is obvious. And huge!

I too thought this when I read it, but just to put forward another view, perhaps increased global temperatures could lead to increased cloud cover, reducing the amount of light plants recieve, leading to less carbon fixation. (I'm merely speculating here, so don't pay too much attention to this.)

I also won't pay too much attention because I forget what the original context was. Your comment about reduced light makes sense.

 

[Andre]

The snow height of Greenland is monitored cautiously. If you check the references on the link at the map it will show that by some local weather phenoma the precipitation at Greenhand has increased, this has caused an increased accumulation rate inland that increases the radial outflow of the ice. The nett effect is a slight higher accumulation rate inland and perhaps due to the increased water runoff activity and the regional warming the erosion at the edges has also increased.

http://aol.wff.nasa.gov/aoltm.html

edit: the site doesn't downlink so hit the link "arctic ice" on the left, and find the link in the text "You may view some examples of Greenland data," and then the link in "The overview of the findings are shown in this map." phoooey.


It seems that the arctic temperatures are subject to cycles as http://home.wanadoo.nl/bijkerk/Arctic.jpg would demonstrate. Temperatures are roughly the same as in the 1940's

 

[reasonmclucus]

Warmer temperatures near the coast of Greenland could easily lead to greater snow/ice precipitation inland.

One of the peculiarities of snowfall is that warmer temperatures, so long as the air temperature remains below freezing, can produce greater snowfall because the air can hold more water. Water temperatures, and coastal air temperatures, above freezing with inland temperatures below freezing tends to increase snowfall inland. The area over the water, and possibly coastal areas, can hold more moisture than the air over colder inland areas forcing the excess moisture to condense and then form ice crystals once it gets far enough inland. The best example of this process is the lake effect snows in Buffalo in which wind blowing over open water carries moisture into the colder air over Buffalo..

In general water, and the air above it, changes temperature slower than land and the air above it. Over the long run, during a warming period water obviously becomes warmer. If a cooling trend develops, such as a reduction in solar energy output or reception, land temperatures would drop below freezing sooner than water temperatures. Water would continue to evaporate at a relatively high rate increasing the potential for heavy snows inland. This process explains how warming periods can turn into ice ages relatively quickly.