Atmospheric Science, the weather, and global warming

[scaeagles]

OK....been a while. I was going to post this in the random thoughts thread, but I though it deserved its own.

Storm season below average (http://www.weatherstreet.com/hurricane/2006/hurricane-atlantic-2006-below-normal-season.htm)

I am not here to debate global warming. I fully admit that the earth is getting warmer at present, I just don't believe that man is the cause. Anyway.....

I found this to be quite interesting. Many educated people believe that the two record setting hurricane and tropical depressions seasons in 2004 and 2005 are directly tied to global warming, and the sea surface temperatures will continue to rise, which will lead to huge hurricane seasons every year.

Well, thus far, 2006 is below the average of 1944-1996, and nowhere near any sort of record setting level. Sea surface temperatures are below normal.

I have long thought that the complexity of the atmosphere and forces at play in determining weather phenomena are too complex to predict even with reasonable science. Who would have thought that with record air temperatures across the planet sea surface temperatures would have dropped to bvelow average. It is counter intuitive.

This is why I don't buy into the doom and catastrophe predictions related to global warming. I don't think man causes it. I don't think man had much, if any, control over it. And I certainly don't think anyone has any idea how it all works. Massive predictions of devastating hurricanes were all there were prior to the season starting.

It is true there will probably be some. But not many. And with the seas temps as they are, if they stay as they are, there may not be anything major.

More confirmation for my skepticism.

[scaeagles]

And then there are quote like this from the head of the National Hurricane Center, Max Mayfield -

"I think the day is coming. I think eventually we're going to have a very powerful hurricane in a major metropolitan area worse than what we saw in Katrina and it's going to be a mega-disaster. With lots of lost lives," Mayfield said.

"I don't know whether that's going to be this year or five years from now or a hundred years from now. But as long as we continue to develop the coastline like we are, we're setting up for disaster."

Duh. That's like saying building on earthquake fault means buildings will be destroyed by earthquakes.

[Nephythys]

I agree.

I've read reports about how the earth was hotter back when dinosaurs roamed- and I doubt they were driving cars and using aerosols.

Man has been around for but a moment of this planet's history- throughout that history the earth has warmed and cooled and gone through it's cycles- with or without us.

[innerSpaceman]

It's completely possible that the heat cycle we seem to be starting is a natural phenonmena. I find it ostrich-like, however, to think that the massive atmospheric alterations caused by human activity - unknown in our planet's history and on a pretty massive scale - would have zero effect on climate.

Perhaps the earth has methods of compensating for human-activated atmospheric change. Global pandemic perhaps.

[Moonliner]

Hummm...

It looks like we are both reading the same headlines. Perhaps we should merge these threads (http://www.loungeoftomorrow.com/LoT/showthread.php?t=4200)....

[Stan4dSteph]

Sea temperature rises are also contributing to massive coral reef death. Loss of coral reefs will contribute to increased coastal erosion.

The global climate is a very complex system, so I don't think we can point to the lack of hurricanes so far this year to say "see they were all wrong!"

Less waste is better for everyone.

[Alex]

The people connecting last years hurricanes to global warming with any certainty were engaged in hyperbole. Very few atmospheric scientists (pretty much all of whom believe in anthrogenic global warming) were willing to make the connection and generally discounted it.

No individual piece of weather can be taken as a sign of climate. Even in the midst of a warming climate we'll have very cold winters. In the midst of a decades long drought there will still be big rain storms.

A stronger connection can be made between the warming and the strength of the hurricanes that did happen than between warming and the number of hurricanes that happened.

[scaeagles]

The people connecting last years hurricanes to global warming with any certainty were engaged in hyperbole. Very few atmospheric scientists (pretty much all of whom believe in anthrogenic global warming) were willing to make the connection and generally discounted it.

Perception is reality. I have cited here that the links between global warming and increased hurricane activity were bogus at best.

The media was certainly overplaying it, and if I recall, one of the posters for An Inconvenient Truth had a gigantic hurricane on it. The attempt by many in the media and those who are pushing for huge reform is to link two very active seasons in 2004 and 2005 to global warming.

This is why it is so hard to sort out fact from hyperbole. The sensational story of impending disaster with unstoppable causation is better than the story of a statistical anomaly.

[Gemini Cricket]

Uh oh. Spoke too soon. Here comes Debby! (http://news.yahoo.com/s/ap/20060823/ap_on_re_us/tropical_weather_17)

[SacTown Chronic]

I've often wondered why conservatives demand that the existence of global warming be held to a higher burden of proof than the existence of WMDs or even God.

[Alex]

Perception is reality.

Who's perception gets to be the reality? Because your perception on this one doesn't match mine.


and if I recall, one of the posters for An Inconvenient Truth had a gigantic hurricane on it.

Yes, An Inconvenient Truth talks about Hurricane Katrina but it doesn't say that global warning caused Katrina. It uses Katrina as an example of what we can expect to see more of if the predictions for global warming effects are accurate.

Presumably you'll agree (or accept the voluminous scientific evidence) that warmer surface water temperatures increase the strength of hurricanes and that Katrina was strengthened by the high temperatures in the Gulf of Mexico last year (don't worry, I'm not asking you to agree that those specific temperatures were caused by global warming)?

So what to expect then, asks the film, if global warming makes those high surface temperatures into the standard condition rather than annual anomolies.

[mousepod]

This thread reminds me of a great line Keith Olbermann said at the beginning of the month, when talking about the current heat wave in regards to global warming:

In some respects, asking whether one particular heat wave stems from global warming is a little like asking whether one individual sneeze was caused by the sick man‘s pneumonia. A heat wave is just one potential symptom.

[Moonliner]

OK....been a while. I was going to post this in the random thoughts thread, but I though it deserved its own.

Storm season below average (http://www.weatherstreet.com/hurricane/2006/hurricane-atlantic-2006-below-normal-season.htm)

I am not here to debate global warming. I fully admit that the earth is getting warmer at present, I just don't believe that man is the cause. Anyway.....


I'm not sure that I really understand the point you are trying to make with this thread.

First you say you don't believe that human created pollution is responsible for global warming. You then assert that global weather is too complex a subject to understand. So in essence what you are saying is that due to ignorance on how global weather actually works humans are not responsible for global warming. That's not good science.
It would seem that a more defensible and scientifically valid viewpoint would be to conclude that we don't know what factor human pollution is playing in global warming and go from there.

Also, Am I safe in assuming that you don't think the current level of pollution created by humans is a good thing? Should we not be making every effort to cut back on pollution worldwide regardless of what effect it's having on global warming? So what does it matter if global warming is created by humans or not? We still need to take the steps to clean up our collective act that are generally recommended by the green's.

[scaeagles]

I've often wondered why conservatives demand that the existence of global warming be held to a higher burden of proof than the existence of WMDs or even God.

Don't think I said it wasn't happening. I said there isn't really direct proof that it is man caused, especially considering the history of warming cycles on the earth.

[scaeagles]

Who's perception gets to be the reality? Because your perception on this one doesn't match mine.

Yes, An Inconvenient Truth talks about Hurricane Katrina but it doesn't say that global warning caused Katrina.

I'm talking about the perception often put forth by the media. I haven't seen An Inconvenient Truth, but for what purpose would the massive hurricane on the poster be there for? It is designed to give the perception that global warming is causing killer hurricanes. This is the perception I was talking about. It isn't the case that global warming is causing killer hurricanes, but it would seem like there is a goal to make the perception to be such.

[scaeagles]

I'm not sure that I really understand the point you are trying to make with this thread.

Simply that the panic about the hurricane season, and what I believe to be an intentional linkage of record hurricane seasons to global warming, isn't coming to pass. No one comes out and says reduced hurricanes mean there is no warming. Plenty of people say increased hurricanes are caused by global warming.

I didn't say man may not be a contributing factor to warming. However, the natural cycle of the earth is to have warming periods and cooling periods. It has happened long before man produced green house gasses. My point is that I am tired of doom and gloom being thrown at me about warming when I do not believe that man is capable of doing anything about it. It happened before we produced greenhouses. It will happen regardless of what man does.

[katiesue]

I am tired of doom and gloom being thrown at me

Perhaps a cherrier avitar is in order then? ;)

[scaeagles]

There is a difference between experiencing doom and gloom in the present and merely predicting it.:)

[Not Afraid]

I'll guess we'll just hav e to wait and see. It's not like any changes we make are going to have sudden results. So, do whatever you want to. I don't have children who will be living in the mess we leave.

[Moonliner]

I'll guess we'll just hav e to wait and see. It's not like any changes we make are going to have sudden results. So, do whatever you want to. I don't have children who will be living in the mess we leave.

Whereas I have taught my children to do the dishes every night. I'm getting them used to idea of cleaning up after us. :)

[Alex]

It is designed to give the perception that global warming is causing killer hurricanes.

No, it is to say that global warming is going to cause massive hurricanes. It is impossible to pin any individual hurricane on global warming but if global warming sets in to a sufficient degree it is pretty much accepted by everybody that the hurricanes will be bigger.

Kind of like it is impossible to pin any individual case of lung cancer on smoking, but smoking certainly causes plenty of lung cancer.

[scaeagles]

No, it is to say that global warming is going to cause massive hurricanes.

The the relatively educated, certainly. To the uneducated masses, though, knowing that the movie is about global warming, and knowing that there were lots of big hurricanes recently, the conclusion most easily reached is that global warming is causing these big hurricanes now.

[Cadaverous Pallor]

I agree with Leo about scare tactics and linking stuff to recent catastrophes.

As usual with this kind of thing I am not surprised and I'm not horrified. People from all sides have used scare tactics torn from the headlines of the day to push their causes. One could even argue that in the face of a moral dilemma, it's not immoral to use these tactics, as long as it wakes people up. One could argue this but I'm not sure I'd swallow it.

I don't pretend to know whether it's right or wrong, but I do know it's expected. Just like politicians and salesmen lying.

This all has nothing to do with global warming or anything else, it's just a fact.

[innerSpaceman]

hate to break it to you, scaeagles ... but the uneducated masses are not the folks who are going to be exposed to An Inconvenient Truth.

[scaeagles]

hate to break it to you, scaeagles ... but the uneducated masses are not the folks who are going to be exposed to An Inconvenient Truth.

But the posters with the hurricane....I'd bet they have seen the posters.

[innerSpaceman]

Even I haven't seen the posters.

[SacTown Chronic]

Leo tore them all down to protect the children.

[Alex]

The the relatively educated, certainly. To the uneducated masses, though, knowing that the movie is about global warming, and knowing that there were lots of big hurricanes recently, the conclusion most easily reached is that global warming is causing these big hurricanes now.

So who is to blame for stupid people jumping to conclusions? And why aren't they educated. All they need to do is take 90 minutes before just assuming that their preferred pundit will tell them the truth about how awful/wonderful it is.

Atmospheric scientists have been spending the last 15 years trying to "educate" people on what they believe is happening and what it may mean. It's their fault that the idiots of the world prefer to get their opinions from talk radio and network political dramas?

[Frogberto]

It's a matter of being safe rather than sorry. We know that human activities release carbon. We also know that carbon is released in a natural cycle. What we CAN do, is to minimize the compound effects of both together, by doing at least the following:

1. Making industry more efficient; and
2. Exploring alternative non carbon energy and fuels.

What's wrong with either? Industries seek efficiency anyway, and nobody wants to be burning coal, or petroleum, in 100 years either.

Part of the problem could be human activity, but its a compound effect that worries scientists in the field. To quote one of 8 articles on the problem from this month's Scientific American:

"Retreating glaciers, stronger hurricanes, hotter summers, thinner polar bears: the ominous harbingers of global warming are driving companies and governments to work toward an unprecedented change in the historical pattern of fossil-fuel use. Faster and faster, year after year for two centuries, human beings have been transferring carbon to the atmosphere from below the surface of the earth. Today the world's coal, oil and natural gas industries dig up and pump out about seven billion tons of carbon a year, and society burns nearly all of it, releasing carbon dioxide (CO2). Ever more people are convinced that prudence dictates a reversal of the present course of rising CO2 emissions.

The boundary separating the truly dangerous consequences of emissions from the merely unwise is probably located near a doubling of the concentration of CO2 that was in the atmosphere in the 18th century, before the Industrial Revolution began. Every increase in concentration carries new risks, but avoiding that danger zone would reduce the likelihood of triggering major, irreversible climate changes, such as the disappearance of the Greenland ice cap."

[scaeagles]

Conservation is fine. Efficiency is fine. Alternative sources of energy are even preferable. It is not my point to say that these things are not. I am merely saying that climate change happens, and it has happened long before man pumped one spec of CO2 into the atmosphere (or any other gas). I think it is futile to think we have the capability to stop or affect this on a global scale.

[Alex]

I am merely saying that climate change happens, and it has happened long before man pumped one spec of CO2 into the atmosphere (or any other gas).

This is the contral point of An Inconvenient Truth. Global climate has always changed over time. And looking at those changes there is a strong correlation between average global temperature and levels of atmospheric CO2. Here's a chart showing how well they correlate for the last 400,000 years (the period over which temperature and CO2 information is readily available from ice cores).

http://www.seed.slb.com/en/scictr/watch/climate_change/images/carbon_dioxide.jpg (http://www.seed.slb.com/en/scictr/watch/climate_change/causes_co2.htm)

So, the real question is what should we expect to happen with that big spike in the green line right at the end of the graph. There is no question that current levels of CO2 are much higher than at any time in the past 400,000 years. There is no question that this is mostly anthrogenic.

Where therre is a question is what will happen in response. Perhaps there is some holistic breaking system that will prevent temperature from snapping as far as CO2 levels otherwise indicate. Perhaps while CO2 and temperature are correlated there is not a causal relationship (though the theory on the causal relationship is pretty well grounded).

But if there is a causal relationship between CO2 levels and mean global temperature and there is not systemic breaking mechanism on temperature are we willing to experience the consequences?

That is the fundamental question of the anti-global warming crowd. The outcome is not certain, but are we really willing to risk it?

Considering that we've essentially deforested continents, we've killed off global fisheries, we've drained bodies of water almost as big as the Great Lakes, I have no problem with the idea that we've altered the global atmosphere. It really isn't all that big.

[sleepyjeff]

Any chance we could see that graph with Margins of Error included?

[Stan4dSteph]

Any chance we could see that graph with Margins of Error included?It's based on data from NOAA. You might start there.

[Alex]

I'm sure it is, though I haven't the time to do it. All the raw data is available from NOAA. However, so long as the margin of error is consistent across the time period it wouldn't change the correlation.

[Drince88]

Does anyone mind (not LOTers, the general press) if we wait until AFTER hurricane season to say this is a 'below average' one!?

I'm not worried too much about Debby - It's "Tropical Depression 5" that I'm watching! (5 day cone pointed right between the Yucatan Peninsula and Cuba!)

[sleepyjeff]

Move back to Portland where all you have to worry about is Volcanoes;)

[Frogberto]

Any chance we could see that graph with Margins of Error included? Sure - the margin of errors aren't a secret, and the NOAA data charts and NASA data charts always have them:

http://whyfiles.org/218glo_warm/images/variations.jpg

This is a UN chart, but the grey areas represent margin of error. Note the smaller (although stil existent) margin of error in the later data, which is direct measurement from Mauna Kea of Carbon Dioxide. In this graph, the yellow represents the margin of error:

http://aim.hamptonu.edu/graphics/outreach/gallery/lg/co2graph.jpg

I think you're implying uncertainty here, and there's always a level of uncertainty. But you can show CO2 levels with a simple calculation. If you begin with the year 1750, generally accepted as the beginning of the Industrial Revolution, when the standard measure for CO2 levels was 278ppmv, add the known level of human-generated CO2 for that year, then subtract 2.84% of the excess CO2 – because that's how fast nature tries to restore the balance. If we do this for 255 years, up to 2005, we get the pink line in the graph below. It fits the black line – the actual CO2 level – like a glove.

http://zfacts.com/metaPage/lib/zFacts-CO2-predicted-measured.gif

How accurate is this fit? Considering the difficulties of gathering data from centuries past, amazingly close. We know, for example, that up until 1950, deforestation was putting about as much CO2 into the atmosphere as were burning fossils, but it's not easy to know how many trees were chopped down in, say, 1850, and how much CO2 this put into the air. In spite of imperfect data, the fact that a simple calculation predicts the extraordinary shape of actual CO2 so well is clear evidence this can not be a coincidental convergence. Human CO2 emissions must have caused the upsurge is atmospheric CO2.

So what? The link between human activity and rising CO2 levels is the first step. The next one is between CO2 and global warming. That was predicted over 100 years ago, but the evidence has become convincing only very recently.

CO2 Level information, by the way, comes from two sources. From 1958 forward, they are from a weather station high atop the Mona Loa volcano in Hawaii. They are so accurate, they show levels going up every autumn, when the leaves fall, and coming down every spring. Earlier data are from ice cores in Antarctica. The two sources agree remarkably well.

[sleepyjeff]

Thanks for the margin of error graph, Frogberto.

[innerSpaceman]

And I'll bump this once more just so's everyone (heheh, especially naysayers) gets a better chance to see them.

[jdramj]

If you begin with the year 1750, generally accepted as the beginning of the Industrial Revolution, when the standard measure for CO2 levels was 278ppmv, add the known level of human-generated CO2 for that year.....


Ok not to be one of those "naysayers", but I'll be one. Exactly how does one measure the amount of CO2 in 1750? :D

[Alex]

Because atmospheric gasses get trapped in ice at the poles (well anywhere really, but at the poles the ice doesn't melt so much). So if you know how old the ice is, there are complicated tests you can do to get a sense of atmospheric composition at the time.

This is how we can get gas compositions for hundreds of thousands of years. There is some really old ice laying about. For recent centuries there are some other methods as well.

[Frogberto]

Ok not to be one of those "naysayers", but I'll be one. Exactly how does one measure the amount of CO2 in 1750? :D Nothing wrong with being a nay-sayer. But as Alex Stroup pointed out, ice core samples are one way to get a direct measurement, although not the only way.

This encyclopedia article (http://en.wikipedia.org/wiki/Ice_core#Paleoatmospheric_sampling)has a good review of how direct atmopheric testing of atmosphere from centuries past is done.

There is a major ice core measurement center in Greenland, that has been used to reconstruct a history of climate from ice cores. When snow falls it carries with it the compounds that are in the air at the time, compounds ranging from sulfate, nitrate and other ions, to dust, radioactive fallout, and trace metals. When snow falls in a place where temperatures above freezing are rare (there is only a hint of any melting at the GISP2 site in the 750 year record recovered to date), such as in polar regions or at high altitude, the snow from one year falls on top of the previous year without melting.

As each yearÕs snowfall is buried by successive years' snowfall, the constituents contained in the snow are buried along with it. By drilling down from the surface of an ice sheet and analyzing snow from greater and greater depths, a history of the compounds in the air can be obtained. Further, snow that is deeper than 80 meters at the GISP2 site turns into ice from the weight of the snow above it, and trapped in the ice are small bubbles of air. Thus, in addition to trapping compounds from the air, an ice sheet traps a small sample of the air itself. This trapped air is also analyzed and provides information about the composition of the atmosphere at the time the ice formed.

Like ice cores, deep sea cores also provide information about climate, but from accumulated sediments on the ocean floor. Unlike ice cores, which provide direct climate information, sediment cores provide indirect information. An example of this indirect evidence is the method for determining temperature. When sediment cores are analyzed researchers painstakingly sort out plankton shells which twist in different directions depending on the temperature of the water they grew in. By counting the number of shells that twist each way the temperature of the surface water at the time that they grew can be determined. Understanding the behavior of these plankton in the modern world is necessary to produce a historical record of temperature for the ocean.

Sediments also accumulate very slowly relative to snow on an ice sheet. This results in much longer records from sediment cores, but a much reduced ability to resolve short term changes. While periods of hundreds to thousands of years might be resolved in a sediment core, annual and even seasonal resolutions are possible with ice cores. On the other hand, sediment cores can provide records which are as long as several million years compared with the several hundred thousand years of ice cores. Because of these differences, sediment cores and ice cores provide complimentary climate information; ices cores provide high resolution, direct information and sediment cores lower resolution, less direct records, but from much longer time periods.