Is global warming unstoppable?

YES
It was not until I was nearly 40 and returned to school that I had any idea about how dynamic our planet is. My return to school as a geology major was the direct result of a job I had taken with a major oil company. One of my first assignments was to type the edited manuscript for a training course on petroleum exploration for recently graduated geologists, who believed they knew everything about geology, but in reality knew little or nothing about petroleum exploration. Typing that manuscript was my first hint about the dynamism of Mother Earth.

When the global warming scare started, it sounded frightening and serious, but only momentarily. I began checking geology information sources to verify that what I thought I knew was still correct, and no new theories had disproven previous studies and conclusions.

Then I began to wonder why so many so-called illustrious scientists were joining the global warming hoopla. My impression was that they either weren't earth scientists and had specialized in other disciplines, or Mr. Gore had somehow convinced them that this was a stoppable man-made situation. Perhaps they were dazzled by the thought of having their names linked with Gore's. I was reassured only by the occasional letter to the editor of the local newspaper from professional geologists who boldly questioned the whole idea.

One generally accepted fact is that for the last 7,000-10,000 years, we have been emerging from The Great Ice Age. During that time, four cycles of cooling and warming have been identified and named. Many scientists believe that most recent Great Ice Age was only the latest in the planet's history, but sound evidence of similar earlier events is lacking.

What is certain is that there have been many climate changes during the earth's history, though the reasons for many remain uncertain. Some, though, are known, including the world-wide effects of massive volcanic eruptions that can lead to mini-ice ages or relatively short cycles of extreme climate changes. New England experienced below average temperatures from 1811-1817, with 1816 being by far the worst year.

Between 1812 and 1815, there were 4 major volcanic eruptions. They spewed enough ash and debris into the sky to make a cold period worse. In the northeastern U.S. in 1816, snow fell in July, and summer temperatures were significantly below normal. Similar latitudes on the other side of the planet experienced the similar conditions. Crops that managed to begin growing early in the season were killed off by summer frost, ice, and snow; people froze to death.

So in addition to the earth's normal cyclical temperature shifts, massive eruptions, meteor strikes, and other natural phenomena can at least temporarily affect the climate.

We know that large areas of North America were under water in the past. If you want the evidence, get a good fossil hunting guidebook, head for the Colorado Rockies, and find for yourself the evidence of ancient seas and the fossilized remains of sea creatures on high mountain tops. Before the Rocky Mountains were pushed up, they were part of an ancient sea floor, during a period when there were no glaciers and the oceans rose dramatically and created inland seas.

When the temperatures dropped, the inland seas dried up as the water evaporated and fell to earth again as snow, which was compressed to ice, which formed glaciers that reached well into the northern latitudes. Now the cycle seems to be at least temporarily reversing.

The glaciers are retreating, as they have done before, causing the sea level to rise. How long this warming will last is impossible to know. In information found on the internet, I saw no mention of whether this might be another temporary glacial retreat, or perhaps is the beginning of an extended period of warming. It doesn't matter. Even if it's temporary, it's unlikely that it will completely reverse during our lifetimes, which do not occupy more than a fraction of a tick of the second hand on the geological clock.

There could, of course, be an abrupt temporary change caused by other geological events. For example, the magma chamber under Yellowstone National Park is under constant surveillance by the United States Geological Survey (USGS) because the magma has been rising to the surface, causing surface deformation and seismic activity of low to moderate magnitude. In December 2007, 184 earthquakes were recorded, with the highest magnitude being 3.6.

According to the USGS, "Three extraordinarily large explosive eruptions in the past 2.1 million years created a giant caldera within or west of Yellowstone National Park " One of my geology instructors firmly believed that a Yellowstone eruption could happen again at any time. The USGS evidently agrees and issues daily volcano status reports, aviation warnings, and earthquake activity summaries. Another extraordinarily large eruption will, no doubt, eject enough pyroclastic material into the atmosphere to cool things down for a while by blocking much of the sun's light from reaching and warming the planet.

There are many actions we can and should take to improve quality of life, such as reducing the emissions that cause smog and pollution and make our air dangerous to all living things; we can find new sources of energy to heat our homes and businesses; we can stop filling every vacant bit of countryside with waste that may never biodegrade.

I do not believe, however, that we can control the normal dynamic processes of the planet. I must admit that trying to scare people into believing that we can seems to be an effective way to get support to make your own movie, win a Nobel prize, and get your name back on the front page! But it won't stop global warming.

NO

Let us look at a few facts surrounding both global warming and global cooling that the media and the strongest proponents of the theory ignore and do not like to address in any way. The best way to do this is to give a brief and rather rough history sketch.

Two hundred million years ago, the earth was a hot, steamy, vegetated ball. Average temperatures were much higher than they are today. Great but shallow inland seas covered much of the continents and plant life grew in such profusion as to make the densest rain forest of today pale in comparison. Just as today, water vapor was the greatest of greenhouse gases. Polar ice caps didn't exist, which was nothing new since for over nine tenths of the time the earth has been around, it hasn't had ice caps.

Through it all, there were uncountable times of temperature fluctuation and climate change.

Then, for reasons not at all understood, global temperatures began to fall. Some scientists attribute this to the meteor impact 65 million years ago that they believe caused the extinction of the dinosaurs. Other theories have also been put forth, but the cause is not truly important to this discussion as will be seen.

As temperatures dropped, precipitation began to fall as snow in the extreme northern and southern latitudes. Instead of melting, the temperatures were just low enough for it to begin accumulating. Since snow and the ice it compacts into reflect sunlight back into space, the temperatures continued to drop, producing yet more snow. Over a great deal of time by our way of thinking of it, probably hundreds of thousands of years, much of the globe became covered in a dense and thick sheet of ice. Most of what was to become Europe and North America lay under a crushing blanket of ice as much as one to two miles thick.

Still, there were fluctuations in global temperature, and at times the ice sheets retreated nearly to where they are today, before once again growing. The periods of heavy ice are called glacial periods, and those with little ice are called interglacial periods.

The last interglacial period began between 10,000 and 11,000 years ago. Ice sheets dwindled, but not at a constant rate, rather in starts and stops. One of the peaks of this interglacial occurred about 2,000 years ago, when global temperatures were several degrees higher than they are now, but still far less than before the glaciation first began. After that, average temperatures dropped until a few centuries ago, when they again began to rise. They are still rising, having risen less than a degree in the last century, and though temperatures are still less than 2,000 years ago.

It takes very little to realize that while we don't fully understand the reason for the fluctuations, it is obviously a naturally occurring event or chain of events. This being the case, it is just a matter of time before the trend reverses itself once again, as it has so many times before. It is possible or even probable than in the coming thousands of years, most of earth will again be encased in ice.

The initial answer must then be; no, global warming isn't unstoppable. Nature caused it, and nature can and almost certainly will stop and reverse it. If the question was changed a little though, so that it read, "Is global warming unstoppable by man?", the answer would be Yes. Man hasn't been around nearly long enough to have much to do with this natural process. He doesn't have the knowledge, power, or ability to do much to affect temperature changes on a global scale. Even a man caused nuclear winter would have only a passing effect on global temperatures.

As destructive as man is, as much as he pollutes, as much as he squanders, it is only his arrogance and overwhelming belief in his own self-importance that allows him to think that he can affect in any great way, the temperatures of the entire earth. Make no mistake; man can decimate all life on this planet. But he cannot control the natural planetary cycles that have been in place for billions of years. Man is neither that powerful, nor that important.