Like Beauty, the interpretation of scientific data is often in the eye of the beholder. I’m an engineer with more than a smattering of book-learning in the geologic sciences. It has always struck me as appalling that the scientists who would reorder our very lives around their interpretation of climate science and its implications for our future have so little interest in earth history and the geologic time scale. Climate scientists seem to focus on time on the order of a human lifespan, or the timescale of written history as the only time frame of interest.
But in terms of the geologic time scale, human history is the blink of an eye compared the 4.5 billion year age of the earth. The end of the last ice age, a monumental, undeniably non-anthropogenic warming event, happened about 12,000 years ago; to a geologist it may as well have happened a week ago last Thursday. Yet climate scientists rarely address the implications of that warming event on their modern-day warming theories.
But this week, a new study came out which alarmingly concludes that CO2-forced temperatures are at or near their Holocene (post ice age) maximum.
One could look at the same data and wonder how cold we might be if not for Global Warming.
The New York Times (along with just about every other mainstream news outlet) this week reported the news that, for them, closes the case on Global Warming:
Previous research had extended back roughly 1,500 years, and suggested that the rapid temperature spike of the past century, believed to be a consequence of human activity, exceeded any warming episode during those years. The new work confirms that result while suggesting the modern warming is unique over a longer period.
Even if the temperature increase from human activity that is projected for later this century comes out on the low end of estimates, scientists said, the planet will be at least as warm as it was during the warmest periods of the modern geological era, known as the Holocene, and probably warmer than that.
That epoch began about 12,000 years ago, after changes in incoming sunshine [!!] caused vast ice sheets to melt across the Northern Hemisphere. Scientists believe the moderate climate of the Holocene set the stage for the rise of human civilization roughly 8,000 years ago and continues to sustain it by, for example, permitting a high level of food production. [Emphasis added. - Ed.]
And their “Dot Earth” blog chimed in:
While the researchers, led by Shaun Marcott of Oregon State, conclude that the globe’s current average temperature has not exceeded the warmth that persisted for thousands of years after the last ice age ended, they say it will do so in this century under almost every postulated scenario for greenhouse gas emissions.
That blog post has a curious graph and caption as a sidebar, which I have magnified here:
Indeed, it shows the abrupt warming at the very end of the last ice age, followed by several thousand years of temperatures well above the 1950 baseline. For the last 5,000 years, though, the planet has been cooling, a trend that has even accelerated for the last 2,000 years.
But for some real perspective, let’s look at some data from the Vostok Ice Core. It affords a look at the last 400,000 years of earth history, encompassing several ice ages.
The top graph shows CO2 concentration in the atmosphere; the bottom one shows average temperature departure from the 1950 value. Two observations are readily apparent:
- For the last 400,000 years at least, “normal” = “COLD!”
- The warm periods are but brief interludes between ice ages. Wild temperature fluctuations were common before any possible impact of human civilizations. The anomaly is the stability of the moderate temperatures during the Holocene, the last 12,000 years (indicated by my red arrow), when warm weather fostered the development of human agriculture, cultures and civilization.
Consider what a global ice age would mean. Cincinnati, OH and points north would be under a glacier hundreds of feet thick (not necessarily a bad thing, in the mind of some readers and SEC football fans). Agriculture would be impossible in North America. The planet could sustain a tiny fraction of its current population.
Even with a cooling of a couple of degrees Celsius, crop yields and growing seasons would shift dramatically for the worse. It would be increasingly difficult to feed the planet.
Given the choice between Global Warming and Global Cooling, give me Warming any day.