At this point in history, it is hard to avoid the topic of climate change — it is in the news, all over Twitter (X), and even part of daily conversations. Although there are a number of people who understand the how behind climate change, there is still a majority that doesn’t quite get why this is happening or how long we have known about the processes behind it. In this article, I will break down greenhouse gases and the greenhouse gas effect, as well as touch on the carbon cycle. Climate change and global warming is complex, but understanding the mechanics behind it can help us understand which changes need to be made now and why.
The effects of climate change
As many people have noticed, over the past few decades there have been an increase in the number of extreme weather events. Hurricanes have been increasing in severity, such as Hurricane Katrina and Hurricane Sandy. Flooding in Europe, South Korea, Turkey, the US, and Pakistan over the past year has been devastating — with some claiming that extreme flooding should be seen as the “new normal”(Zhou, 2023). The increasing warmth of the planet increases the amount of moisture in the air, leading to more extreme precipitation events. But what about the opposite? Although there is more moisture in the air, this will not fall equally. Droughts are plaguing areas around the globe, and as a result, forest fires are becoming more and more frequent (Mansoor et al., 2022). These extreme events are often affecting those most vulnerable — low income nations without the budget to prepare for natural disasters, countries where large shifts in weather are already common, and people living in poverty without the means to move out of these areas. But what is causing all this? Can it really be a result of burning fossil fuels?
Greenhouse Gases and the Greenhouse Gas Effect
The increased warming due to the greenhouse gas effect was first discovered in 1827 by Jean-Baptiste Fourier, a French scientist (Houghton, 2017). But what is the greenhouse gas effect? The easiest way to think about it is by thinking about how a greenhouse works. In a greenhouse, the sun warms the area through solar radiation. Some of this radiation is reflected by the glass, but most of it heats the ground, plants, and air in the greenhouse. In order to stay in equilibrium, the area heated by solar radiation must also emit radiation — infrared radiation. In this scenario, the ground emits infrared radiation, or heat waves, back into the greenhouse. But unlike in the open air, these radiation or heat waves are trapped in the greenhouse by the glass. This results in the greenhouse being much warmer than the surrounding open air, which is great for our agricultural system!
For the earth, greenhouse gases (carbon dioxide, methane, ozone, etc) and water vapor work like the glass in the greenhouse. These particles trap the infrared radiation, bouncing it in all directions but especially back towards the earth. Not only is the earth being warmed by the sun, but also by the heat/radiation that the earth must emit back into the environment. See figure 1 below for a visual aid for this process.
We now understand the why behind greenhouse gases and their contribution to global warming. Now it is time to understand how our behaviors contribute to a larger system, also known as the carbon cycle.
The carbon cycle
All the carbon on earth is already here. When we are burning fossil fuels, tilling agricultural fields, or removing peat bogs, we are not creating new carbon, but simply changing the state of the carbon. This is not a new thing. Carbon has been cycling since the beginning of life on the planet — it is being released when animals die, trapped when it is buried under soil, absorbed by the ocean, and processed by plants and animals (National Ocean Service, 2021). However, current human behavior is significantly altering the carbon cycle. The planet and atmosphere are not accustomed to sudden, large increases in available carbon due to anthropogenic factors (Mehmood et al., 2020) and there is no natural process in the carbon cycle that will “save us” from the effects of releasing so much carbon, so suddenly (Falkowski et al., 2000). So if we cannot rely on natural processes to save us, how do we stop global warming?
Adaptation and Mitigation
Adaptation, adjusting to or reducing the effects of climate change, and mitigation, preventing or decreasing the things that cause climate change, will be the main tools for humanity in the coming years. Mitigation can be achieved through a number of different methodologies such as reducing the amount of fossil fuels used, inventing negative emissions technologies like carbon capture and storage, preserving natural areas with high carbon storage capabilities, and geoengineering (Fawzy et al., 2020). However, adaptation is more complex to understand — due in part to the variability. Each region, country, city, and local area will face different effects due to climate change and will have a different capacity for planning and response. However, each adaptation plan starts with understanding hazards, managing risks and uncertainty, and finally building up the adaptive capacity of an area, as outlined by Serret in an Oxfam report (2011).
Conclusion
Although the greenhouse gas effect and the natural carbon cycle are natural processes that have kept our planet at livable temperatures (Houghton, 2015), anthropogenic factors are causing them to be a major risk factor for our future. As a result of increased greenhouse gases, we are seeing an increased frequency of extreme weather events, that will only get worse unless we as a society change our behavior. Hopefully, through mitigation and adaptation strategies, humanity will be able to avoid catastrophic outcomes.
References:
Falkowski, P., Scholes, R.J., Boyle, E., Canadell, J., Canfield, D., Elser, J., Gruber, N., Hibbard, K., Högberg, P., Linder, S., Mackenzie, F.T., Moore, B., Pedersen, T., Rosenthal, Y., Seitzinger, S., Smetacek, V. & Steffen, W. 2000, “The Global Carbon Cycle: A Test of Our Knowledge of Earth as a System”, Science (American Association for the Advancement of Science), vol. 290, no. 5490, pp. 291–296.
Fawzy, S., Osman, A.I., Doran, J. & Rooney, D.W. 2020, “Strategies for mitigation of climate change: a review”, Environmental Chemistry Letters, vol. 18, no. 6, pp. 2069–2094.
Houghton, J. Global warming: The complete briefing. (Cambridge: Cambridge University Press, 2015) 5th edition. Chapters 1 and 2, pp.1–33
Mansoor, S. et al. (2022) ‘Elevation in wildfire frequencies with respect to the climate change’, Journal of Environmental Management, 301, p. 113769. doi:10.1016/j.jenvman.2021.113769.
Mehmood, I., Bari, A., Irshad, S., Khalid, F., Liaqat, S., Anjum, H. & Fahad, S. 2020, “Carbon Cycle in Response to Global Warming” in Environment, Climate, Plant and Vegetation Growth, eds. S. Fahad, M. Hasanuzzaman, M. Alam, et al, Springer International Publishing, Cham, pp. 1–15.
National Ocean Service ‘What is the carbon cycle?’ (2021).
Sterret, C. (2011). Oxfam Research Reports Review of Climate Change Adaptation Practices in South Asia. Oxfam. Available at: https://oi-files-d8-prod.s3.eu-west-2.amazonaws.com/s3fs-public/file_attachments/rr-climate-change-adaptation-south-asia-161111-en_3.pdf
Zhou, L. (2023) The ‘New Abnormal’: The rise of extreme flooding, briefly explained, Vox. Available at: https://www.vox.com/climate/2023/7/11/23791452/nyc-flooding-brooklyn-weather-climate-change (Accessed: 17 October 2023).
