by Jim Rhodes
A report just released by the National Research Council (NRC) has confirmed that global climate change is real. The report, called “Reconciling Observations of Global Temperature Change” examines the discrepancy between ground–based temperature readings and satellite measurements. The National Research Council is part of the National Academies of Sciences and was set up to provide accurate, objective, and up–to–date scientific information to Congress.
Funded by the National Oceanic and Atmospheric Administration and the Aluminum Corporation of America, the study was prompted by the need to reconcile ground–based temperature readings with those from satellites. The ground–based readings have shown that global temperatures have risen somewhere between 0.7 and 1.4 degrees Fahrenheit during the past century. However, satellite measurements taken over the past 20 years do not correlate well with ground–based temperature records taken and instead show that the atmosphere in the low–to–mid troposphere may actually be cooling somewhat!
The NRC concluded that both sets of data are correct. The cooler satellite readings may be due to dust and other pollutants in the low–to–mid troposphere. However, the ground–based readings, taken over a much longer period of time, show that temperatures near the ground have been steadily increasing. According to John M. Wallace, chair of the NRC panel, “The differences between the surface and upper–air trends in no way invalidates the conclusion that the Earth’s temperature is rising.” Wallace also stated that “the rapid increase in the Earth’s surface temperature over the past 20 years is not necessarily representative of how the atmosphere is responding to long–term, human induced changes, such as increasing amounts of carbon dioxide and other ‘greenhouse’ gases. The nations of the world should develop an improved climate monitoring system to resolve uncertainties in the data and provide policy–makers with the best available information.”
The ground–based temperatures are significant in that this is where we humans and nearly all other living things actually are. We know, for example, that the ice cap over the North Pole has been getting significantly thinner at least since nuclear–powered submarines have been moving under the ice cap in order to escape detection. We also know that the last decade has been the warmest on record for at least several centuries.
The solution to global climate change is still being debated. There are profound ethical, political, economic, and social issues that must be resolved before international agreement on effective strategies can be reached. The Kyoto treaty on global climate change has yet to be ratified by the US Senate. In the meantime, the Sierra Club and other organizations are the pushing the federal government to adopt higher CAFE (corporate average fuel efficiency) standards for automobiles sold in the United States.
Others believe that stronger measures are needed. (See “Are Energy Taxes a Good Idea?” in this issue). However, the longer the world waits to act, the worse the problem is likely to become. Once weather patterns change, the change is likely to be with us for a long, long time. Global climate change could even lead to rapid shifts in weather patterns due to chaotic, unpredictable feedback effects. More data and more research are still needed. But, as the NRC report indicates, the preponderance of evidence shows that global climate change is indeed real.