Adapted from:
Carlisle, John. "Natural Factors Cause Global Warming." Opposing Viewpoints: Global Warming. Ed. James Haley. San Diego: Greenhaven Press, 2002. Opposing Viewpoints Resource Center. Gale. Higher Colleges of Technology. 3 Feb. 2010

Natural factors cause global warming

In the following viewpoint, John Carlisle argues that the global temperature has increased because of natural changes in the earth's temperature. It has not been the result of human activity. Carlisle describes periods from the earth's geologic history that had temperatures warmer than at present and believes that people will benefit from a warmer planet as they did in the past. Carlisle is the director of the Environmental Policy Task Force of the National Center for Public Policy Research, a conservative/free market foundation in Washington, D.C.

People have been arguing for nearly a decade over what to do about global warming. But one thing which is very often not discussed is the fact that the Earth is getting warmer because of natural changes. Not because of man.

Over the last 150 years the Earth’s temperature has increased by 1.5° F (Fahrenheit). Supporters of global warming theory say that this temperature increase is proof that man-made CO2 (carbon dioxide) is a danger to the earth, and will heat up the planet and cause huge flooding, severe storms, disease and a mass movement of environmental refugees, people who have no choice but to move because of changes in their environment. However, the fact is, the planet's temperature has always increased and decreased.

Some scientists predict that by the year 2100 the Earth’s temperature will be the same (from 58° F to 62° F) as it was between 8 500 and 5500 years ago. It is therefore interesting to look back to what people’s lives were like during this time. Most interesting is that during this period the Agricultural Revolution began in the Middle East. This development allowed for the development of civilization as we know it today.

Since this period, the Earth has continued to experience temperature differences. Between 900 and 1100 the climate dramatically warmed. The temperature rose by more than 1° F to an average of 60° or 61° F, that’s 2° F warmer than today. However, judging by how Europe prospered during this time, there is little to be worried about. The warming that occurred between 1000 and 1350 caused the ice in the North Atlantic to retreat and allowed people to colonize Iceland and Greenland. Back then, Greenland was actually green. Europe came out of this in a period that saw wonderful harvests and great economic growth. So mild was the climate that grapes were grown in England and Nova Scotia, Canada.

Between 1200 and 1450, the temperature plunged to 58° F. After briefly warming, the climate continued to dramatically get colder after 1500. By 1650, the temperature hit a low of 57° F. This is believed to be the coldest point in the last 10,000 years. That is why the years between 1650 and 1850 are known as the Little Ice Age. It was during this time that mountain glaciers became bigger in Switzerland and Scandinavia, forcing people to leave their farms and villages. Rivers in London, St. Petersburg and Moscow froze and people were able to hold winter fairs on the ice. There were serious crop failures, famines and disease due to the cooler climate. In America, New England had no summer in 1816. It wasn't until 1860 that the temperature sufficiently warmed to cause the glaciers to retreat.

The 1.5° F temperature increase over the last 150 years, so often said to be proof of man-made warming, most likely is simply a return to normal temperatures following 400 years of unusually cold weather. Even the United Nation's Intergovernmental Panel on Climate Change (IPCC), the chief supporter of the Kyoto Protocol global warming agreement signed in December 1997, concludes that: "The Little Ice Age came to an end only in the nineteenth century. Thus, some of the global warming since 1850 could be a recovery from the Little Ice Age rather than a direct result of human activities."

The result would be warmer nighttime and winter temperatures, fewer frosts and longer growing seasons. Since CO2 encourages plant growth and decreases the need for water, we could also expect bigger harvests over the next couple of centuries. This is certainly not bad news to the developing nations of the world who are struggling to feed their populations. (713 words, FK 11.2)