I’ve written previous articles on the “climate change” and “global warming” controversy (“Climategate”; “Global Cooling?”; and “Unusually Heavy Snow Storms vs. Global Warming”) and I don’t like to be repetitious. However, because the same objections continue to be raised by “climate change deniers” every time there’s a heavy snowfall somewhere or other; or when there’s very cold weather somewhere during the winter time (like Great Britain), I decided I would go ahead and speak about my perspective on these matters once again.
Now I am most definitely not a climate scientist – I’m not a scientist of any sort, for that matter – so I easily get lost when detailed technical arguments are being made by either side of the controversy. My information comes, for the most part, from 3 sources, and I would direct people there for confirmation of what I write – and for technical answers, by real climate scientists, to more “sophisticated” arguments against human caused (“anthropogenic”) global warming/climate change. Those sites are: “Skeptical Science”; “Climate Progress”; and “RealClimate”.
A lot of times, cold weather and heavy snowfall are fused together in people’s minds; they think that the fact that it’s snowing is equivalent to the temperature being extremely cold. The fact is that they are two distinct things. In fact, the heavier snowfalls frequently, if not usually, occur at relatively higher temperatures (the freezing point, or just above or below it). The fact that the area I live in may get 20 inches of snow (which is a great rarity for my area of the USA – we have very little snow here) does not mean that we also were experiencing record (or near record) low temperatures. The heavy snowfall would only indicate that there was a lot of moisture in the air in my area of the country, and the temperature was cold enough (though perhaps just barely) for that moisture to condense and fall in the form of snow.
And that is, of course, the key point as regards heavy amounts of snow. It’s not the temperature that causes the heavy snowfall, but the amount of moisture in the air. How does moisture get into the air? It gets there by means of evaporation. What causes evaporation? Evaporation is caused by heat. The higher the temperature, the more evaporation there will be – and warmer air is able to absorb higher amounts of moisture also. When air flow patterns drive that moist air over my area of the country and it begins to condense into precipitation, that precipitation may well be snow if the temperature is close to the freezing point.
Heavy precipitation events (including snow as well as rain) are in fact an indication of global warming, not a disproof of it. It is exactly what the climate models predict. When climate scientists are predicting heavy precipitation events as a result of warming temperatures, how does one logically use those heavy precipitation events as an argument against global warming? This past year of 2010 has seen a number of such heavy precipitation events – both major snowstorms (particularly in January and February) and rainfall resulting in flooding. Climate scientists who have been warning of such things resulting from warming global temperatures justly point to them as evidence of the correctness of their position. When they tell us that things will only get worse if we don’t drastically reduce the amount of carbon we’re putting into the atmosphere, we should really pay attention.
But if heavy snowfall not only doesn’t disprove global warming, but rather actually indicates it, what about record cold temperatures in certain areas of the world (Great Britain for instance)? How can it be so cold there, if the world is getting warmer?
While, as I said, I don’t understand the details and technicalities of the situation, I believe I have the gist of the matter. No doubt a climatologist or meteorologist will find this very simplistic, but here goes. Even though the arctic is growing warmer, and ice is melting at an alarming rate, the arctic temperatures are still vastly colder than what Great Britain (and most other parts of the world) normally experience. When air flow patterns blow that cold air to another area of the world (Great Britain for instance), that area of the world may very easily experience record cold temperatures (though the arctic may be experiencing record high temperatures).
“Global” warming, of course, refers to world wide temperatures, not just the temperature in this or that particular area of the world. To say that global temperatures are rising slowly but surely does not mean that every area of the world is necessarily warmer. It does mean that the averaged out temperature of the world is increasing. And that is what is happening. Even though Great Britain may be very cold right now (due to arctic air being pushed in that direction), the average global temperature for 2010 (at least for January through November – the December temperatures had not yet been tabulated when I looked a couple of days ago) is the warmest it has been in the history of temperature record keeping. We’ve just set a new record high, the previous record being in 2005.
But to say the world is warming is not to say that the warming is caused by human activity (“anthropogenic”), we are told. That of course is technically correct. There can be any number of reasons for climate change. Increases and decreases in solar activity have an obvious effect on weather and climate. So does volcanic activity or lack thereof. There are all kinds of natural factors that go into forming our climate. So are natural forces causing the current global increase in temperature?
The answer to that is “not so’s you could tell it”. 😀 Solar activity, for instance, has definitely not increased in the past 30 or so years; in fact, if anything it has decreased. We have had some volcanic eruptions, but that would tend to cause a cooling effect, not warming. If there were no human contribution to take into account, natural factors would indicate we were in a cooling cycle, rather than the warming period we’re actually experiencing.
In my article “Global Cooling” I referred to this statement from a report made in 1972: “Judging from the record of the past interglacial ages, the present time of high temperatures should be drawing to an end, to be followed by a long period of considerably colder temperatures leading to the next glacial age some 20,000 years from now. However, it is possible, or even likely, that human interference has already altered the environment so much that the climatic pattern of the near future will follow a different path.”
In the time since that report was published in 1972, an overwhelming majority of climate scientists (something like 97%) have come to the conclusion that it is a virtual certainty that it is “human interference” which is the driving factor of the present trend of global warming. That “human interference” is the amount of CO2 we’re pumping into the atmosphere. It is already causing drastic effects to our environment, and things will only get worse unless we change our ways.
If one doubts that human produced CO2 is causing global warming, the question that would need to be asked would be: “what is preventing this natural result of CO2 accumulation in the atmosphere?” Warming IS the natural result of CO2 in the atmosphere; and when we humans are pumping so much of it into the air, the natural result is unusual warming. If human produced CO2 is not causing abnormal warming, the only logical question is “why not?” And then the next question is: “what IS causing the abnormal warming of our earth?” Perhaps some “climate change denier” can answer those questions; but the usual answers, such as “natural cycles” and “solar activity” are easily rebutted (see the sites I linked to earlier).