The Simple Science Behind Global Climate Change
April 27, 2017
Lately, there has been a significant amount of speculation regarding the legitimacy of scientific findings related to global climate change. Scientifically-deduced conclusions have been met with semi-widespread skepticism in the United States and around the world.
Science is a process that allows and even encourages skepticism. After all, if one scientist has a better explanation, or theory, for some natural phenomenon than another, he or she is expected to produce evidence in the form of observations or quantitative measurements to support his or her hypothesis. This basically means that scientists are constantly trying to outperform each other in an attempt to have the “best” or most complete explanation for why something is the way it is.
However, the problem today is that much skepticism is not based on evidence that contradicts the current theory but instead on a lack of understanding of the theory itself. This is especially pronounced in the debate on climate science. Many people do not believe the earth could be warming at the rate it is because the weather where they live is cold. Many others believe that the earth itself is warming, but it is natural processes that are causing this increase in temperature, rather than human activity.
The second of these two beliefs is somewhat supported by modern science. The earth is warming through natural processes; however, air pollution from coal and other fuel sources is accelerating that natural process. It is easier to believe once one understands the science behind it.
Earth is one of three rocky planets in our solar system that have atmospheres. Obviously, the atmosphere of earth must be incredibly important in the explanation of global climate change; otherwise there would be no point in speaking about fossil fuels pumped into the air. To explain the impact an atmosphere has on global temperature, it is helpful to compare earth to the one rocky planet in our solar system that does not have any significant atmosphere: Mercury. It is especially helpful to note that this planet is the closest planet to our sun.
Now, one would reasonably expect Mercury to be the hottest planet in the solar system. Everywhere on the planet should be hot all the time, right? After all, with such a small distance to our sun (roughly 36 million miles from Mercury to the sun compared to 93 million from the sun to Earth), Mercury should always have immense temperatures, even at night. However, this is not the case. Admittedly, Mercury has the second-hottest surface temperature during the day at about 427°C. Many are surprised to hear, then, that at night on Mercury, temperatures can drop to as low as -180°C. This surely shouldn’t be possible. The lowest temperature ever recorded on Earth was -128°C in Antarctica. Surely a planet that is almost 3 times closer to the sun cannot register a temperature colder than the coldest part of Earth?
This phenomenon can be explained by the presence of Earth’s atmosphere, which serves as a kind of reflector for heat energy that tries to leave the planet. See, Earth’s atmosphere shields the surface from harmful rays from the sun, while letting in energy as light and heat. This heat is absorbed by the earth, but then the heat will attempt to leave the planet to return back to space. Earth’s atmosphere, however, blocks much of that escaping heat and reflects it back down into the surface. While the sun continues to pump more heat energy into the earth, and Earth’s atmosphere refuses to let this energy leave, a gradual warming of the entire planet is observed.
Now, how does human activity have anything to do with this warming of the planet? Well, the gases that humans pump into the air, like carbon dioxide and methane, are extremely good at trapping escaping heat. This can turn into a snowball effect, since a higher atmospheric temperature can increase the amount of dangerous “greenhouse gases” like CO2 and methane in the air. More CO2 and methane means more warming, which means even more greenhouse gases like CO2, water vapor, and methane! It’s easy to see how this effect can spiral out of control and result in the accelerating warming we notice today.
With the science of climate change being readily dismissed by many who do not take the time to understand it, now is a perfect time for citizens and especially students of the United States to educate themselves on the reasoning behind the theory itself.