The COVID-19 Pandemic: Human Health and Earth Systems

In March 2020, estimates of global emissions of CO2 began to show a decrease, but for an unexpected reason: Planet Earth experienced an unusual decrease in human activity as the COVID-19 pandemic spread around the world. Lockdown measures limiting many human activities and forced confinement resulted in decreases in activities such as road and air traffic, electricity demand, and industrial activity. Many people changed from commuting to offices to working from home. Studies of these decreases in human activity report that global CO2 emissions also dropped. For example, Liu, et al. (2020) concluded CO2 emissions decreased by about 9% in the first half of 2020, with the timing of the decrease corresponding to the timing of lockdown measures.

Climate scientists are now exploring the extent to which this decrease will continue, and the effects the lockdowns (and whether or not they will continue) will have on the climate change debate. Some climate change activists argue that the response to this unexpected pandemic showed that it is possible for humans to significantly slow down the emissions of CO2 (and other greenhouse gases) by changing their behavior and thus reducing the levels of fossil-fuel consuming activities. But it took a huge, global health crisis to make that happen. Will this turn out to “wake us up”, and encourage society to change its ways regarding our dependence on fossil fuels? Or, will we just return to “normal” after the pandemic is over?

These are questions that will likely be debated for a long time as the story unfolds regarding the science and politics of the COVID-19 pandemic. But for students taking this course in the spring semester of 2020, it was a more immediate, personal experience. We were faced with a very abrupt and stressful situation, but also a “teachable moment” regarding how humans interact with global Earth processes in ways that can have a direct effect on our lives. Because of increasing concerns about the pandemic, students were abruptly forced to leave campus, and we had to instantaneously switch this course (and all other BC courses) to online teaching. Although this experience was very stressful for all involved, it motivated the addition of a new section of this course on the intersection of global Earth systems, human population growth, and the spread of COVID-19.

The role of humans, human population growth, how humans use resources, and how our activities affect Earth systems, are important aspects of the global climate change story and of the more general intersection of Earth systems and public policy explored in this course. That topic was not adequately covered in previous versions of this course, and I have wanted to add those topics into the course for quite a while. So, this was clearly an opportunity to do that, and it provided a very direct connection of the course concepts with what the students were dramatically experiencing in their lives. And, although personally challenging, it provided one of the best examples of uncertainty and of why the topics for this course are a moving target. Also, some students commented in online class discussions that learning about the science underlying these issues provided at least some comfort during these stressful times.

Thus, the course now has a section on human population, mathematical modeling of human population and pandemics, and the so-called “flattening the curve” that was being discussed in COVID-19 news headlines. We started this topic with human population modeling, which forms a good basis for modeling the spread of diseases and why we were hearing so much about “flattening the curve” to help society deal with the effect of the pandemic.

Reference:

Liu, Z., P. Ciais, Z. Deng, et al., Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic. Nat Commun 11, 5172 (2020). https://doi.org/10.1038/s41467-020-18922-7