Climate Change 101: From Atmosphere to Zebrafish
By Jameson O’Reilly, Physics and Math, 2019
Statistically speaking, unless you are a member of Congress, you probably acknowledge that global climate change is happening and that it is a threat to humanity’s future. Even so, some of the details might be a little fuzzy. The story begins with the Industrial Revolution, which is when humans started using fossil fuels to power factories and their homes on a global scale. Burning this coal and oil released carbon dioxide into the atmosphere, which acts as a greenhouse gas.
Greenhouse gases, including water vapor, methane, and ozone, are very good at absorbing heat from solar radiation. Without greenhouse gases, this energy would either pass by Earth or be transmitted out into space. Because what we usually call “temperature” is really just the average energy of molecules, the extra energy is absorbed by the greenhouse gases and then dispersed to other molecules through collisions, which raise the overall temperature of the atmosphere. This rise in temperature in turn causes most of the other problems associated with climate change, including ecosystem damage, rising sea levels, and extreme weather.
The first step in climate change’s path of destruction is tipping the delicate energy balance that organisms depend on. Most species have evolved to survive in very specific ecosystems, so even small changes can disrupt their metabolism and feeding habits. On top of that, those that do survive will have to deal with a diminished food supply. Suppose that a certain species of plant withers in the increased heat. Now, the herbivores that used to subsist on that plant will have less to eat, so their population will also decrease, which in turn will harm the animals that subsist off of them.
The next step is the extra heat and carbon dioxide leaking into the oceans. Aquatic ecosystems are just as sensitive as terrestrial ones to temperature changes, and the dissolved carbon dioxide creates carbonic acid, which makes the water more acidic. This is another factor that threatens the health of sea life, as the acidity inhibits shell growth in animals like coral, oysters, and shrimp, all of which need their shells to survive.
Finally, climate change is perhaps most threatening at the intersection of water and land. Rising sea levels from the ice caps melting could bury many of our major population centers, including New York City and Boston. Additionally, warmer water evaporates more easily, and more water in the atmosphere means that storms are more powerful, more frequent, and, by extension, more dangerous than ever before.
Our current levels of greenhouse gas emissions threaten life as we know it in many different and interconnected ways, which is why it is imperative that we solve the root problem instead of trying to fix all the individual problems caused by elevated emissions. While it is too late to avoid all the repercussions of our actions, there is still hope to reduce emissions before we are forced to look for a new home elsewhere in the universe.