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        Waxings >> The Environment >> Global Warming: Fact or Fiction?
        
(Message started by: mitakeet on Feb 11^th, 2008, 4:57pm)

Title: Global Warming: Fact or Fiction?
Post by mitakeet on Feb 11^th, 2008, 4:57pm

I really see this as a series of questions rather than a single one:

1) is the Earth getting warmer?
2) if so, is this warming caused by humans?
3) if so, what is the best thing to do about it?

I will address each sequentially below…

1) I will state for the record (being the font of useless information) that as far as all scientific measurements are concerned, the Earth has warmed significantly in the last couple of decades. Indeed, there are several confounding factors that may have lead to a significant under realization of an increase in temps. For instance, large volcanic eruptions throw dust high into the atmosphere and that leads to a measurable cooling effect. Add to that airplanes (and even ocean going tankers and freighters) putting aerosols that act in much the same way as the volcanic ash (at least insofar as a cooling effect is concerned) the Earth has been experiencing a relative cooling effect. Certain forms of pollution, most notably the sulfur-based types that which leads to acid rain, also lead to cooling effects and it is noteworthy to mention that the increase in temps these last few decades very closely tracks the reduction in sulfur pollutants. Hence we may just be seeing the very beginning of a warming trend that might last for decades or much longer.

2) This is the core of the debate right now. Is the warming trend we are observing (accepted as a fact by all but the most hard headed) something due in large, small or no part to human activity? This is hugely subjective and it is incredibly difficult to get unbiased, clear and unambiguous information upon which to draw conclusions. It is true that measurements of CO2 have increased steadily over the past half century. Why this is happening is a subject of a lot of research. The obvious answer that everyone points to is that we are burning huge amounts of fossil fuels each year and pumping the results into the atmosphere. However, as large as that amount is, it is trivial compared with that generated by the biosphere and released by volcanoes. Many like to argue that CO2 is a very sensitive chemical that tiny changes in can result in huge variations in global temps, but I am not sure that this is cause and effect. It could just as easily be that CO2 increases in warmer weathers because there is more turnover in the biosphere. Methane is a much more 'green house active' chemical than CO2 and that, in general, is being seen as increasing in track with the increasing global temps. However, there do not appear to be any direct human causes of increasing methane in the atmosphere (though there are hints that human activities have a secondary effect of increasing the opportunities for methane production (e.g., clearing forest to graze cattle, cattle being a significant source of methane)) so this is a good area of research. People talk extensively about the clearing of land for cities and the so-called 'heat island effect' surrounding cities, but even in crowded places like China there is still a crap load of rural land. The fact that much of that land is under cultivation undoubtedly has an impact, not only in the increase of CO2 (I read an article recently that could explain every bit of the increasing level of CO2 with cultivation) but changes in reflectivity of the land (which, btw, often result in an increase of reflectivity, hence decrease in solar heat absorption). Again making direct conclusions of cause and effect are difficult, if one is to be scientific about it. In the last couple of years there was a report that looked at the reflectivity of the Artic snow and correlated it with temps and see ice amounts. The amount of soot released by natural forest fires in Canada and the US North West has been fairly constant over recent geologic time and the soot particles are quite characteristic. Thus it is pretty easy to distinguish between other types of soot (from burning coal, diesel, gasoline, etc.) and measure the amounts. Additionally, the soot from the forest fires tends to peak quite sharply in certain months and be much lower in other months while human sources tend to be more uniform through out the year. What they reported was that soot originating from human sources appeared to decrease reflectivity of the snow substantially. However, the amount of this soot peaked a couple of decades ago (probably the same reason why sulfur-based aerosols also peaked a couple of decades ago: pollution control). As such, one should expect to see an INCREASE in snow and sea ice since then and we are not observing such a trend. So I do not feel that concluding that humans are directly responsible for the observed increase in temps is valid at this time and it may never be practical to make such a sweeping statement.

Title: Re: Global Warming: Fact or Fiction?
Post by mitakeet on Feb 11^th, 2008, 4:58pm

3) If we accept the conclusion of 2) as 'yes' (which I don't), the next question to discuss is what should we do about it. Actually, I guess there is a camp of people that don't care if the observed warming is the result of humans; they still want to tinker with our ecosphere. There are a huge number of factors (likely billions) that engage in non-linear feedback (see chaos theory) that result in weather. It has proven pretty much impossible to reliably predict hemisphere wide trends, let alone what will be happening outside your window, on time scales of days, let alone weeks, months, years, decades or centuries. Considering that as far as geological time is concerned, humans haven't even existed long enough to measure, even looking at century long trends is of rather dubious value. It is possible (though I consider unlikely) that we could be on the cusp of a run-away warming trend and in a century or less we could have melted polar ice caps and 300 ft more ocean (and lots of new ocean front property for sale!). It is possible (what I consider most likely) that we are seeing normal variation in climate, perhaps influenced to a small degree by human activity, and in a few decades we will see a cooling trend that will lead to increasing ice caps and a tiny (centimeter) reduction in sea level). It is also possible (though also very unlikely in my mind) that we could see a sudden reversal of the warming trend that results in a new ice age and dramatic (100 ft or more) reduction in sea level. Since there are so many confounding factors involved in weather prediction (and the historical inaccuracy only slightly better than guessing) I think it is rather cheeky to even consider any form of manipulation. Sure we could reduce CO2 emissions by reducing fossil fuels (nuclear energy is a great source of power and can easily be made trivially safe, inexpensive and without significant waste for at least 1,000 years; if there is interest I can put that in a post) but who knows, our pumping CO2 out may actually be keeping us from a massive freeze! Since prediction is impossible if we do nothing, how can prediction be any better if we choose to do something on purpose? Why should anyone think that any change is guaranteed to make things better? Who the hell defines 'better'? There are plenty of people getting rich now that the ice is melting faster in the Artic, they won't think it is better if the pole freezes again!

My conclusion is this is all much ado about nothing. Normal weather is highly variable and the middle of the last century saw several decades of unusually mild weather across the globe and now everyone somehow thinks that is the way things should be. Some people argue that doing nothing is dangerous, yet doing something without being able to know you are improving things seems the height of ignorance to me. And another thing: why do you think that all the most expensive weather disasters all happened recently? It is obvious! More people live in more expensive housing in more places subject to extreme weather! Get the morons out of their houses on the ocean sand bar and no one will give a d**n that the sand bar washed in or out to sea a few dozen feet.

As for any conclusions that humans are a despicable species that are raping the planet without regard of any future value, triggering a new 'mass extinction', that is for another post (guess how I feel about that subject!).

Title: Re: Global Warming: Fact or Fiction?
Post by torporchair on Feb 15^th, 2008, 10:30am

Yes, I agree, the Earth is getting warmer, and definitely only the most stubborn person would deny it. It is easy at this point to prove that the Earth is getting warmer, and this makes it easy for people to use that irrefutable fact as half of a fallacy. That is, stating a true fact then stating a possibly true speculation as if it were a proven fact. A great technique to use in order to convince people of something they are already inclined to believe.

It is very possible that humans are responsible for the warming that is taking place. With the amount of rainforest we have destroyed, the amount of carbon we have emitted, and the amount of cow farts we have sponsored, it is hard not to simply assume that humans MUST be the cause of the warming. In fact, for many years I was convinced that it was a proven fact which was only ignored by auto manufacturers and oil drilling investors etc.

But the hard truth is that we are not able to say with any certainty that humans are causing the warming we see taking place.

Regardless of this fact, the destruction of the rainforest is a heartbreaking and despicable thing. And the reliance on such primitive means of transportation is laughable for a species with the potential to be so much more efficient. The entire oil-based economy is such an out-dated and out-moded abomination that it is natural we should deplore the smog and other ill-effects.

We need to get real about how we treat this planet we live on and that we share with all the plants and fish and fellow creatures. We need to clean up our act. But to base this need to clean up our act on the premise that we are causing global warming is a huge waste of credibility and energy and thought-time.

There are more pressing matters than to argue about something that can't be proven one way or another! I am glad Mitakeet (aka the Font) has breeched the subject, simply because so many people are unwilling to accept that we can't know if we are causing the warming. I am always happy to take an unpopular stance when I can, if I feel confident in it.

Byees, byees, harumph. And I thank yer.