Humans: Perpetrators of Global Warming

Is there hope for the future?

Written by: Kylie Jackson & Lindsey Kuczo
Students of Spring 2021 Icehouse Greenhouse Earth 

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Throughout the past century, global atmospheric and oceanic temperatures have increased at an average rate of 0.13 degrees Fahrenheit each decade. This amounts to a total rise of about 1.5 degrees Fahrenheit in 100 years. When it comes to climate, the smallest changes have momentous impacts. For example, just a one degree rise in ocean temperature causes the bleaching of corals, their first stage of death. If temperatures do not decrease, the corals will die, and it takes decades for coral reefs to fully recover. More than 50% of all corals have disappeared in 30 years. Corals support over 25% of the entire ocean’s life, and if they continue to die, there could be a massive extinction of ocean species. Additionally, small changes in temperature can cause shifts in biomes and negatively impact the ecosystems within because of the unexpected variances caused by rising temperatures. This is all due to a small increase in temperature caused by global warming. Global warming is the increase in the average temperature of Earth due to the addition of greenhouse gases into the atmosphere through human activities. Greenhouse gases trap the sun’s heat within the atmosphere. They include water vapor, methane, ozone, and most importantly, carbon dioxide. Therefore, more carbon dioxide in the atmosphere, means more heat being held on Earth’s surface, thus warming the planet further. Since the industrial revolution, carbon dioxide levels have skyrocketed, and these levels are not decreasing. In the past, carbon dioxide levels have fluctuated, but never at this rate or intensity. Many say that global warming is a natural event, simply caused by natural mechanisms, and it will fix itself eventually. This is not the case and serious damage will be done if action is not taken now, but luckily for us, we know the causes of the issue. It is not too late to change our ways and turn the tables on the negative impacts of climate change.

It is a common misconception that global warming is a natural process. The truth is, global warming is natural. For hundreds of thousands of millennia, the world has gone through glacial and interglacial periods; however, what we see today is unprecedented. The rate at which the temperature is rising is unlike anything that has been seen on record. Warming typically takes centuries, if not thousands of years, but today’s warming has occurred within just one century. The difference between today and historic warmings is the source of the warming. Climate change skeptics claim that today’s warming is due to natural systems. However, climate modeling shows that if these natural sources of warming are removed, an exponential growth of temperatures is still seen. This indicates that something other than natural systems are to blame, and the blame points towards humans. 

What are the natural mechanisms that many claim are the cause of today’s warming? One commonly speculated mechanism is volcanoes. This is false because the inputs of carbon dioxide from volcanoes is only a fraction of the amount that humans input. Volcanoes release about 0.15 gigatons of carbon per year, whereas humans release 10 gigatons per year. Moreover, volcanic input is relatively constant, and over time volcanic ash causes global cooling, as the ash reflects the sun’s rays. Therefore, it is unreasonable to assume that the warming is caused by volcanoes. Another proposed mechanism is the sun. Although there has been an increase in solar energy for a long period of time, since the1970s, the sun’s energy has actually been decreasing, proving that this is not the source. A second astronomical cause that people refer to is orbital changes, meaning changes in how close the Earth is to the sun. Orbital changes are the cause of glacial and deglacial periods. If the climate were only dependent on today’s orbital cycles, the planet would actually be cooling, but instead the Earth is warming and at a significantly faster rate than that of any natural mechanism. Finally, many people assume that a redistribution of heat on Earth is the cause, which is inaccurate because the two main heat sinks are the atmosphere and the ocean. If natural systems were the cause, it would mean that the atmosphere would be warmer and the ocean would be getting cooler, or vice versa, but we are simultaneously seeing an increase in oceanic and atmospheric temperatures. To conclude, since the cause is not any of these natural systems, then the evidence points strongly towards human actions as the cause of unprecedented warming. 

Past events, such as the five mass extinctions, give us the opportunity to see the detrimental effects of harming our environment. The Triassic-Jurassic Extinction that occurred 252-201 millions years ago shows just how detrimental abnormally high levels of carbon dioxide can be. During this time, there was a huge spike in carbon dioxide in the atmosphere causing a spike in temperatures and ocean acidification, leading to the extinction of 75-80% of all marine and terrestrial species. Acidification occurs when atmospheric carbon dioxide dissolves into the ocean, lowering its pH, thus making it more acidic to marine organisms. We can clearly see these effects of ocean warming and acidification today as corals and many other sea life that are sensitive to temperature and pH differences are struggling to survive. This is especially harmful to corals because increased acidity prevents them from building their protective skeletons, and it also affects fish when the acidic water enters their gills and impacts their lungs. At the rate in which we are currently releasing carbon dioxide into the atmosphere, ocean acidification will likely worsen, threatening the lives of all marine organisms and their ecosystems. 

Humans are constantly polluting the environment, adding enormous amounts of greenhouse gases into the atmosphere, increasing the greenhouse effect, and worsening global warming. Burning fossil fuels, cutting down forests, destroying ecosystems, and farming livestock are four main ways in which we negatively impact the environment. We rely on fossil fuels in our daily lives: gas for transportation and electricity used to light our homes, charging our electronics, and cooking our food. We cut down trees and use the wood to build homes, and we use the barren land for farming so that we can feed our rapidly increasing population. Trees and plants absorb carbon dioxide out of the atmosphere, which could decrease the amount of greenhouse gases, but by cutting them down we are only worsening the effects. Another major contributor to greenhouse gases in the atmosphere is livestock. With an increasing human population, comes the increased need for rapid food production and livestock, who are responsible for about 14.5% of global greenhouse gas emissions in the form of methane. Each of these human sources of greenhouse gas emissions contributes to global warming and all of the negative impacts it has on our environment. If we do not take action to decrease our emissions, many species living on Earth, could fall victim to the sixth mass extinction. 

While environmental issues and the potential irreversible impacts our actions could have are extremely daunting, there is hope. It is not too late to take action and do your part in saving the environment. Big changes begin with small, personal changes in how we live our daily lives. If possible, use public transportation, walk, or bike to your destination. Take shorter showers and do not let the water run while you are brushing your teeth. Buy items that can be used more than once, such as reusable water bottles. When shopping, try to buy from local stores, rather than big corporations who release massive quantities of greenhouse gases into the atmosphere when producing their items. If possible, eat food that is grown locally, rather than transported and processed. You can save electricity by unplugging your belongings when you are not using them and by turning the lights off when you are not using the room. As a student at UMW, you can also get involved on campus by being an advocate for the environment by getting involved in clubs such as the Ecology Club, Better Energy Awareness and Mobilization (BEAM), or COAR: Environmental Action and Awareness (EAA). Bigger changes, such as using renewable energy, are also extremely helpful, but they are more expensive and not as doable for college students.  If we all filter these small changes into our daily lives, together we can have an even greater impact on the well-being of our environment. It is possible for ecosystems to recover, although it takes some time. In order for humans and other species to thrive, we need to change the way we are living our daily lives. There is hope, as long as we all work together and recognize the severity our current actions will have on the future of our planet.