Global Warming 101

March 30, 2008

A caveat: I am not a scientist. But, I have researched and read enough and wish to pass along my findings. I call this piece: Global Warming 101

A very thin layer in the earth’s upper atmosphere – just down from the stratosphere – keeps our planet’s temperature in check and enables us and other living things (plants and animals) to live. Every thing on this planet has become adapted to the temperature regime.

The temperature of this planet – due to tilting, rotation and other factors relative to the amount and angle of sunshine – does vary considerably. Along the equator, the average temperature is quite high. But, even along the earth’s warmest latitude there is variation ranging from the very wet tropics to very dry deserts. Progressing north and south from the Equatorial Zone, the temperature falls gradually. The coldest spots year around are at the north and south polar regions: The Arctic and Antarctic.

The most species are found in rainforests’ tropical areas, and this dwindles until very few terrestrial species can live year-around at snow and ice fields of the North and South poles. However, aquatic species – fish - flourish in the cold waters of the Arctic and Antarctic regions and the few mammalian species that are present are predators of the fishes or each other.

Life on Earth varies widely, but we all depend upon the upper atmosphere to keep the temperature at levels all living things have adapted to over millennia. There have been, to be sure, extremes in the distant past – the Age of the Dinosaurs ended rather abruptly when the Big Lizards could not adapt to a drastically changed environment. But, since these extinctions, mammals thrived.

But, back to the upper atmosphere. Similar to the transparent or translucent coverings of a greenhouse that let in warming sunlight and hold in the heat produced by that sunlight warming up the inside of the greenhouse, that’s the way our upper atmosphere works. The sun shines through the level high above our heads, but heat is reflected back down when this protective dome is encountered.

There are three essential gases – called “greenhouse gases” since they function in the same way as a greenhouse does. The greenhouse gases are water vapor, methane, and carbon dioxide. Water vapor has remained relatively constant – the percentage that’s up there now is about the same that was up there thousands of years ago. Not so with methane and, particularly, carbon dioxide. A vastly increased number of domestic animals release methane gas through their digestive systems – flatulence. Methane gas is also released in large quantities as the previously-frozen tundra thaws out. Frozen tundra essentially prevents methane from escaping, and as it reaches a temperature above freezing, methane is released.

But, it is carbon dioxide that is becoming much more prevalent in the upper atmosphere.

Burning almost anything releases carbon dioxide – burning fossil fuels releases the most. There are also millions of acres of forest that are no longer. The trees capture carbon dioxide in the process of photosynthesis and release oxygen. The fewer trees on the planet, the less CO2 captured. Scientists refer to trees and other vegetation as a “carbon sink”.

There is absolutely no doubt about the upper atmosphere serving as a “greenhouse” – one that keeps our temperature relatively stable. We depend upon non-varying levels of water vapor, methane and carbon dioxide in the upper atmosphere to maintain a temperature regime that supports life.

But, since the Industrial Age, and particularly in the last 50 years, CO2 in the upper atmosphere has increased dramatically – thanks primarily to an exponentially-increasing population that has led to equally increased amounts of cars, truck, and airplanes and a huge increase in the number of coal-fired power plants. All of these require the burning of fossil fuel and burning gasoline or coal release carbon dioxide. This carbon dioxide rises – being lighter than air – and eventually over several decades reached the upper atmosphere.

Many scientists predict all sorts of dire scenarios if we don’t convert to energy sources that don’t burn fossil fuels. Over 2500 climate scientists that comprise the United Nation’s International Panel on Climate Change – IPCC - in a report released in 2007 stated that we need to make this conversion within the “next two or three years”, but as yet, there have been few moves to make such changes. Instead, the focus in this country – which produces over 25% of the world’s carbon dioxide - has been on ways to burn yet more fossil fuels, but to “sequester” the carbon dioxide produced.

There have been several such proposals for sequestering carbon dioxide, mostly involving sending the carbon dioxide into impermeable caverns. Unfortunately, such plants and such proposals cost billions of dollars each, and the federal government (in the form of the Department of Energy) has balked at funding the plants and proposals. At this time, carbon dioxide sequestration must be viewed as an experiment that has yet to be performed.

The other unfortunate aspect of sequestration is that it will take years – at least a decade – to build a coal-fired plant that sends carbon dioxide underground, rather than into the atmosphere. But according to the scientists of the IPCC, we don’t have a decade, we have at the most three years.

There are, to be sure, a few skeptics among the scientists. For the most part, those companies that profit from the continued use of oil and gas as energy sources fund the skeptics. BUT, even those skeptics acknowledge now that the global temperature is going up. It is the contribution from humans that they deem to be at issue. They claim that the earth goes through cycles of warming and cooling and the current episode is nothing more than a normal cycle of warming.

However, they cannot deny that the amount of carbon dioxide in the upper atmosphere has increased dramatically. It is also undeniable that the only valid reason for this is human activity.

Next month, I will take a look at some of the dire predictions and make some suggestions about what we should to do. Hint: We don’t need to live in caves or trash our automobiles. -----end-----