The Threat of Global Warming
Introduction Global warming is real, and demands immediate action. This paper supplies support for the reality of the situation and discusses what can be done to turn the problem around. Discussion In an article entitled ―How We Know Global Warming Is Real‖ author Tapio Schneider answers that very question. Among other indicators, he points out that ―atmospheric carbon dioxide concentrations are higher than at any time in the last 650,000 years‖ (Schneider 31). They are higher now than they were before the Industrial Revolution, and Schneider attributes the increase to human activities, ―primarily the burning of fossil fuels‖ (31). He reminds readers that carbon dioxide is what is called a ―greenhouse‖ gas, as are ―methane, nitrous oxide [and] water vapor‖ all of which are found in nature (Schneider 31). These greenhouse gases ―act like a blanket for infrared radiation, retaining radiative energy near the surface that would otherwise escape directly to space‖ (Schneider 31). This is a natural process, but problems arise when there is an increased amount of carbon dioxide in the atmosphere; when that occurs, the natural process is greatly augmented: ―it increases the radiative energy available to Earth’s surface and to the lower atmosphere‖ (Schneider 31). Unless some other process compensates for the increase in energy, the result is warming (Schneider 31). The next question is how we know carbon dioxide concentrations have increased, and here Schneider explains that the amount of gases in the atmosphere
have been measured since the late 1950s (Schneider). These measurements have revealed a steady increase in the amount of carbon dioxide in the atmosphere, from about ―315 parts per million … in the late 1950s to about 385 ppm now‖ (Schneider 31). It’s also possible to look at ice core samples from the polar regions that tell us what the climate was 650,000 or more years ago; these tests reveal that ―carbon dioxide concentrations have never been higher than they are now‖ (Schneider 31). The next question is how we know that human activities are the cause of the increasing carbon dioxide, and the answer is that there are ―several lines of evidence‖ to prove this (Schneider 31). The first one he explores is that we know ―approximately how muc