One year ago, I believed that man-made global warming was true, with temperatures rising dangerously due to increasing levels of carbon dioxide (CO2) in our atmosphere. I also believed that a consensus of the international scientific community supported these conclusions. I based these beliefs on information from the popular press, television and political leaders. Then I began some real research on the topic. I quickly discovered three critical things:
First, the Earth has experienced significant warming over the past 18,000 years that has nothing to do with human activity. Second, more recent temperature variations demonstrate that there is little or no correlation between levels of atmospheric CO2 and temperature. And third, there is no “consensus” among scientists on climate change.
To understand the science of climate change, you must first know that very accurate historic temperature data going back thousands of years are available through analysis of dead corals in ocean sediments as well as ice cores from Greenland and Antarctica. You must also understand what the Earth was like 18,000 years ago. Back then, our planet was at the peak of its most recent major ice age. At 18 degrees Celsius, average ocean surface temperatures were 5 degrees lower than they are today. Half of North America and Eurasia were covered by massive ice sheets thousands of feet thick and sea level was more than 400 feet lower than today. Then, the Earth began a dramatic warming and the ice age ended. The increase in the Earth’s temperatures over 18,000 years has not been steady. In just the past 1,000 years, average ocean surface temperatures have fluctuated between 22 degrees C and 25 degrees C. Today the average temperature is 23. Nine-hundred years ago, when CO2 levels were lower than today, global temperatures reached what is called the “medieval temperature maximum.” The world was warmer than today. Sea surface temperatures were 24 degrees C and the southern tip of Greenland, which had been settled by Vikings, was actually green and habitable with a European agricultural lifestyle. Unfortunately for the residents of Greenland, temperatures soon began to fall.
The Earth reached the depth of what historians call the “Little Ice Age” in about 1600 with an average ocean surface water temperature of 22 degrees C. With no help from humans, global temperatures rose significantly from 1600 to 1900. It is true that the levels of CO2 in our atmosphere have been rising over the past hundred years as global society has industrialized. But increased CO2 stimulates increased plant and tree growth. And there are many natural ways CO2 is created, including by the breathing of humans and animals. CO2 is essential to life and feedback loops are complex. Further, temperatures have not risen in correlation with the increase in CO2. Global temperatures actually decreased between 1940 and 1975, increased from 1976 through 1998 and remained relatively unchanged between 1998 and 2006. Since 2006, temperatures have declined.
This year record snowfall and low temperatures are being reported all over the world, from the Americas through Asia to Europe. In just a few examples, this winter the European nation of Slovenia set a record low temperature of minus 49 degrees C and travel in Madrid was hindered by the deepest snowfall in years. Record snowfall and winter storms have forced Minnesota officials to cancel an annual dog-sled race and closed schools and roads in Las Vegas. Even Malibu, Calif., and Houston, Texas, have experienced rare snowfall this winter. Lower temperatures have also led to an expansion in Alaska’s glaciers.
Once you look beyond the political beliefs of the man-made global warming or climate change movement, the scientific truth is that there is no evidence of a correlation between atmospheric temperatures and CO2 levels.
The idea that there is a “consensus” among scientists supporting man-made global warming also is plainly untrue. According to the U.S. Senate Environment and Public Works Committee Minority Staff Report released this winter, “more than 650 international scientists” who are considered experts in the atmosphere disagree with the global warming theory. This is 12 times the number of scientists who authored the pro-global warming “United Nations Intergovernmental Panel on Climate Change 2007 Summary for Policymakers.”
While no correlation has been demonstrated between CO2 levels and temperature, early data do suggest a strong correlation between changes in surface activity on the sun (sunspots) and temperatures on Earth. So, it might be that the same forces that have guided the changes in Earth’s atmosphere for eternity are still at work and still beyond human control. Despite the science, many who advocate dramatic, state-dictated changes in our economy to reduce carbon levels view man-made global warming as “sacrosanct”—an indisputable, dogmatic fact. As we debate climate change legislation—which would have negative economic effects on all of us—it is time to move beyond belief to scientific understanding.