We are at war with science, and now, more than ever, we need to be armed with the facts (real facts, not alternative ones). One of today’s most contentious issues centers around our impact on the climate, specifically, how carbon dioxide (CO2) emitted from fossil fuels is causing the climate to change.
Unfortunately, climate change has turned into a belief system, where you are either a Climate Change Believer or Climate Change Denier. I can’t tell you how strange this is for scientists to hear. We spend our lives trying to remove biases and arrive at unarguable facts — and climate change is one of them.
Below are a few statements you might encounter when talking to a climate change denier and how to respond with the science.
“But CO2 variability is natural.”
Part true. CO2 does vary naturally over both short and geologic time-scales, but the magnitude and rate of change that we are seeing today is unprecedented. Over the last 800,000 years, we saw a natural rise and fall in the concentration of CO2 that coincided with shifts in glacial and interglacial periods (these historical climate shifts were driven mostly by changes in solar radiation caused by variation in Earth’s orbit, but were amplified by CO2 concentrations).
The last major rise in CO2, an increase of ~80 parts per million (ppm), happened between 17,000 to 11,000 years ago. In the last 47 years, CO2 has jumped by the same amount. That’s a 200-fold increase in the rate of CO2 emissions, which is most certainly not natural.
When someone tries to hit you on this issue, insist they address the rate, not CO2 variability in general.