Fact: CO2 is Rising Exponentially. And, New Beginnings for the Climate Corner.

            Welcome back, readers!

            Atmospheric CO2 has increased exponentially. This is a provable fact.

            The reason for this exponential growth is multi-faceted. First and foremost, we are emitting more CO2 today than we were one hundred twenty years ago. In 1900 global emissions were only 5 x 10^8 (five hundred million) metric tons. In 2015, global emissions were 1 x 10^10 (ten billion) metric tons (https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data). The global output of CO2 has increased by two orders of magnitude, a 100-fold increase! This is exponential growth. If you need a refresher on scientific notation and orders of magnitude, watch this helpful study video: https://www.youtube.com/watch?v=DXTuYjPDjqQ.

As our economies have grown, so has our global consumption of fossil fuels. Humans cannot produce goods and services without energy, and we have chosen to use energy that takes tens of MILLIONS of YEARS to form through geologic processes, but only a matter of DAYS for us to extract it from the ground and burn it.

Second, I mentioned the importance of lag times and feedback loops in my Systems Thinking article. Carbon dioxide stays present in the atmosphere for a whopping 100 years! As far as the atmosphere is concerned, it’s only 1921 and we are feeling the residual warming from CO2 emmitted by our ancestors with the advent of the Model T. This also means that our great grand babies will be feeling the effects of warming caused by OUR emissions today all the way in 2121! If you build upon something in an increasing fashion, the rate of change accelerates. This lag time in CO2breakdown has allowed it to accumulate to extraordinary levels, levels this planet has not seen for the last 3 million years. And again, to reiterate, bipedal hominids (our evolutionary ancestors) have only existed for 2 million years.

            Regarding feedback loops, we’ve already begun tipping key Earth systems into new equilibriums. For example, permafrost in the arctic tundra is melting at an increasing rate which releases methane, a GHG 30 times more powerful than CO2. This accelerates warming even more! Mass coral bleaching events are another example of a system reaching its breaking point. Corals are habitat for many species, and according to the geologic record, the oceans die first in extinction events.

Compare the Vostok ice core graph of atmospheric CO2 (https://www.researchgate.net/figure/Graph-from-the-Vostok-Ice-Core-for-the-past-800-000-Years_fig5_339130657) to the graph of human population throughout history(https://www.science.org.au/curious/earth-environment/population-environment). There is a sharp increase in one variable over very little time. If we continue on “business as usual” meaning “growing and emitting at the same increasing rate” we will warm six degrees Celsius. This will sterilize ninety percent of life on Earth. We cannot in good conscience keep emitting as we have been. This is why climate scientists urge us to cut emissions so that we warm fewer than two degrees Celsius: our species (and others) will have a better chance of surviving. We are pressed for time because there is already warming “baked into” the atmosphere from our past and current emissions. This is why I stick my neck out and write. Catastrophic climate change is an issue much bigger than my personal safety or the hurt feelings of letter writers who viciously and repeatedly lie about this topic. Carbon dioxide has increased exponentially and this is not up for debate. One can either accept the reality of atmospheric chemistry and its consequences, or one cannot.

Alas, dear readers, this is the final edition of Megan's Climate Corner. Thank you to the Trinity Journal for the opportunity to share information about Earth with all of Trinity County. They took a gamble on me and gave my first column a home. I am very grateful. Thank you, Mr. Wagner, and thank you to the entire Trinity Journal team.

The next edition will appear the second Wednesday of January 2022 with a new name and email address for the New Year (for copyright purposes), but the same complex, quality climate content presented in an approachable manner. We will continue to explore environmental topics in depth while marveling at the majesty of our unique, one-in-a-million home planet and its place in the universe. See you next year!