Global Warming, Caves may hold the Key

[L Roebuck]

Is global warming causing stronger hurricanes? Caves may hold the answer.
mongabay.com

Scientists have shown that cave formations could help settle the contentious debate on whether hurricanes are strengthening in intensity due to global warming.

Measuring oxygen isotope variation in stalagmites in Actun Tunichil Muknal cave in central Belize, a team of researchers lead by Amy Benoit Frappier of Boston College have identified evidence of rainfall from 11 tropical cyclones over a 23 year period (1978-2001). The research -- the study of ancient storms is called paleotempestology -- could help create a record of hurricanes that would help researchers understand hurricane frequency and intensity. Currently, reliable history for hurricanes only dates back a generation or so.

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[Brian Roebuck]

I hope they aren't sawing off stalagmites etc to do this research. I can't see how they would do it otherwise though except maybe by drilling for samples etc.

This is supposed to help figure out if global warming makes more hurricanes. I think the issue is much more complex than just average global temperatures on the rise. For example: could massive undersea volcanic action raise the sea temperatures enough to cause more hurricanes?

I still have a hard time believing that global warming is directly caused by man alone. Our knowledge of past climate is not very good and it is known that climates cycle up and down over thousands of years (Ice Age anyone?). There are so many variables to take into account such as the precession of the earths axis, solar activity, volcanic events, etc etc. I think the increase in CO2 is hurting us by adding to a warming trend but not actually driving the trend itself. Just my humble opinion.

[Azurerana]

Arrghhh....1978-2001 is 'paleotempestology' I don't think so... What is the growth rate of these stal? I know of stal which have formed 1973-present---date is induitable, because the handrails were put in in the winter of 1973-74. But they are not very big. And how 'blind' was the study? Not indicated in the abstract, either.

I would cast a skeptical eye on these data. They don't extend hurricane knowledge any further BACK in time than what the article says are 'reliable' data. The abstract, unfortunately, does not give the methodology used-- often tiny hollow core drills are used to sample stal, with barely perceptible results on the stal. The O16/018 method is pretty good at defining climatological events, but this research seems too recent to have much application-- the stal wouldn't have had time in 24 years to have dried out, for one. How do they 'know' that these are cyclonic events, and not just big rainstorms?

I would say that the study raises as many questions as it resolves, though presenting corroborative evidence to current hurricane data on a recent scale might be useful for justifying correlating similar ancient signatures to cyclonic activity back then .

[Azurerana]

drbeaner said:

I still have a hard time believing that global warming is directly caused by man alone. Our knowledge of past climate is not very good and it is known that climates cycle up and down over thousands of years (Ice Age anyone?). There are so many variables to take into account such as the precession of the earths axis, solar activity, volcanic events, etc etc. I think the increase in CO2 is hurting us by adding to a warming trend but not actually driving the trend itself. Just my humble opinion.

We actually have a pretty good idea of past climactic conditions and temperature, based on sea level changes and the characteristics of prehistoric plants and animals, stable isotope studies andthe chemical compositon of fossis . By climactic, I'm talking in terms of thousands to tens of thousands of years-- not season to season variability. Precession of the earth's axis isn't a big factor, as much as (astronomical) Milankovitch cycles and their effects on the earth's climates and relationship to plant and animal extinctions. it's pretty clear that, based on sea level and fossils, the Cretaceous was warmer than it is now. The overall warming occurring now is to be expected as the tail end of the last Ice Age. The earth has warmed and cooled over the last 500 million years--prior to that date, information is fairly sketchy.

What the cause for concern is, is not the warming, but the rate of warming increase since 1825. (1816--the year without a summer due to the explosion of Mt Tambora) made the few years of cooling after Mt. Pinatubo look like a small hiccup. There really isn't any other factor which has changed dramatically in the last almost 200 years except the increase of human population, and the decrease of species diversity. Contrary to some of the extremists--it's not that people are generating so much of the heat-- (though there is some, obviously)--it is that increasing levels of haze, and greenhouse gases (including water vapor) in the atmosphere are preventing the escape to space of heat input to the earth by sunlight. I read a couple of days ago one climatologist say, "We haven't turned up the furnace that much, but we've put another blanket around the earth." Methane contributes 4x greenhouse warming than CO2-- before the production of oil and gas, the amount of methane in the atmosphere was negligible. it was relatively recently that oil and gas operations captured the methane; until the 1930s, it was pretty common to just flare off the wells, which wasn't a very good or efficient way to get rid of the methane. Flare offs still occur fairly commonly--we saw a bunch in Illinois and Indiana a couple weeks ago. Like it or not, due to air travel, there is a whole lot more atmospheric mixing than there is without it; not to mention the addition of contrails and exhaust where no clouds were before. Everyone knows about the ozone hole, and acid rain, but the effects of other human made gases on the atmophere are not that widely known.

I could go on and on, but the bottom line is this: even if the cause of warming isn't entirely anthropogenic, we're still the only ones who can cease and desist or do anything about it. Why not at least give it a reasonable try?

After all, the law of the jungle is adapt, make changes, or die.