During the Pleistocene ice sheets close to 2 miles thick covered the earth, the ground temperature was much cooler, and sea temperatures were 3 to 4 degrees cooler than they are today.
Change of a single degree in ocean temperature can cause irreversible changes or cessation in the movement of ocean currents. Florida and the Bahamas are a perfect example used to demonstrate the drop in sea level during the Pleistocene.
As you can see by the picture, sea levels dropped close to 300 feet in Florida, exposing larger land mass, aiding large animals in their transition from South America to North America via the Great American Biotic Interchange (Florida Museum).
Pleistocene land mammals were probably the single most important food source for Upper Paleolithic humans. On the contrary, depending on who you talk to today, people are sustaining a healthy lifestyle by living off the land or eating a diet rich in meatless protein, such as legumes.
Grasslands and cooler environments are indeed favorable for large land mammals, as the case was with megafauna during the Pleistocene, but today we don’t depend on them for survival.
Although it’s easy to have faith in humankind that we will find a way in a warmer world, I can’t help but question the actual facts presented by NASA’s Goddard Institute for Space Studies. Read this excerpt from the article, Global Surface Temperature Change, by J. Hansen, R. Ruedy, M. Sato, and K. Lo, and see how your outlook for humans in a warmer world changes.
The 12-month running mean global temperature in the GISS analysis has reached a new record in 2010. The new record temperature in 2010 is particularly meaningful because it occurs when the recent minimum of solar irradiance (defined as the amount of radiant energy emitted by the Sun over all wavelengths that fall each second on 11 sq ft (1 sq m) outside the earth's atmosphere) is having its maximum cooling effect. At the time of this writing (July 2010) the tropical Pacific Ocean is changing from El Nino to La Nina conditions in the tropical Pacific Ocean. It is likely that global temperature for calendar year 2010 will reach a record level for the period of instrumental data, but that is not certain if La Nina conditions deepen rapidly (Hansen et al 2010).
Each decade that passes, global warming continues without any fear of slowing down. Temperature anomalies furnished by NASA and NOAA, effectively illustrate the never declining warming trend of the earth that is occurring on decadal time scales.
In essence, let’s consider our situation here in Florida. When temperatures rise to over 90°, what kind of clothing do you see people wearing? What if the temperature rose to 120°? 150°? and how about 200°? Is there any question in your mind whether you could cope in such conditions?
Unless there’s a way to shield our bodies from the sun, whether that’s by protective clothing or underground living spaces, I fail to see how we’d ever be prepared for such an event. We won’t experience these changes in our lifetime, but generations of humans, plants, and animal species after us might.
This is my opinion. So what's yours? Please leave comments below.
Global Surface Temperature Change