The Plague and Spanish influenza, two incredibly devastating diseases for the human population, are just a small fraction of pandemics that have swept the globe throughout all of human history. Most of the major world pandemics have occurred before the Industrial Revolution and the invention of automobiles, so there is no feasible correlation between human impact on the environment and prevalence of pandemics.
While the impact of COVID-19 is devastating, it is not unprecedented. The Plague of Justinian killed roughly 10% of the world's population at the time, and the Spanish Influenza pandemic that followed WWI infected 1.4 billion people and killed roughly half a million. Both of these pandemics, as well as the Bubonic Plague sweeping across Europe in the mid-14th century, were before human impact on the natural environment was felt as profoundly as today. The Spanish Flu occurred relatively shortly after the invention of the automobile, and most other plagues in our history were before the Industrial Revolution in 1850. Therefore, no definitive correlation between humans affecting nature and the prevalence of pandemics has been proven. No matter how humanity treats the earth, pandemics will unfortunately happen. We cannot prevent them.
Though most pandemics did not occur after the invention of the automobile, there are countless harmful effects on humans that can result from global warming, especially in developing, low income countries. Pandemics in an age of pollution are not necessarily the worst of our fears, especially because of the effects that air pollutants can have on the lungs. They can put "you at risk for lung cancer, heart attacks, stroke and in extreme cases, premature death." Our effect on the environment should not be overshadowed by the effects of COVID-19 and the pandemics throughout history, and the death toll may be even greater within the next thirty years. Just because there is no evidential correlation between pandemics and the environment does not diminish the profound consequences that global warming has on humanity.
[P1] There have been pandemics throughout history. [P2] Therefore, the relatively recent dissemination of the environment by humans is not to blame.
Rejecting the premises
[Rejecting P2] Global warming can kill more people within the next thirty years than all the pandemics throughout history. These pandemics cannot diminish the profound effects that the environment can have on all of humanity.