Each week, Symposium Magazine invites an author to guest-blog. This week, Prof. Scott K. Taylor is blogging about “Weather and War, Reconsidered.”
Scientific consensus holds that our current climate change is caused by increasing atmospheric levels of greenhouse gases, especially carbon dioxide. But what about climate change in the seventeenth century, before the industrial revolution initiated the ever-increasing amounts of carbon dioxide in the atmosphere?
The answer is sun spots. The seventeenth century saw a paucity of sun spots, which astronomers at the time could notice thanks to the newly invented telescope that let them observe the sun, and its spots, more closely than ever before.
Appearing as dark spots on the surface of the sun, sun spots are the visible manifestations of intense magnetic activity, which also produces solar flares that jet enormous amounts of energy out into space. In other words, a decline in sun spots means a decline in the amount of energy that the sun pumps out into the solar system and to the earth.
It is worth noting that Geoffrey Parker’s focus on climate change before the industrial revolution in “Global Crisis” sidesteps today’s debates about whether human activity creates climate change. He merely points out that the evidence is overwhelming that the earth’s climate has changed in the past and is changing now. Climate-change deniers focus on the causes of the changes, rejecting the case that carbon dioxide or other gases produced by humans can cause a temperature shift.
The inference from “Global Crisis” is that does not matter as much why it is changing; instead, we must do what we can to mitigate and forestall climate change as much as we can. As Parker writes, we must “choose whether it is better to invest more resources in preparation today or live with the consequences of inaction tomorrow.”