Could a sea level rise of 7 to 23 inches by the end of this century wipe out civilization as we know it? What about a rise of 420 feet over the last 18,000 years? If you do the math, you’ll discover that both scenarios work out to about the same average sea level rise of approximately one-quarter-inch per year. Obviously a lot of land has been claimed by the sea in 18,000 years, but wouldn’t any intelligent civilization simply have retreated up the beach as the water rose? Where’s the big catastrophe that resulted in the “lost civilizations” we’re all looking for? And if the rise has been more or less consistent since the end of the last ice age, what impact does global warming have?
A project funded by the National Science Foundation studied the Earth’s transition from ice age to greenhouse about 300 million years ago and concluded that early global warming resulted in wild swings in temperature as the rising levels of greenhouse gases transformed the earth. According to the team of researchers from five universities and the Smithsonian Museum of Natural History, the effects on forests and vegetation were dramatic. During this ancient period, carbon dioxide rose from about 280 parts per million (ppm) to nearly 2,000 ppm. This is the same increase scientists expect to see by the end of this century as the planet’s remaining reserves of fossil fuel are burned!
So, while global warming is definitely a serious concern today, it appears that it may have caused radical changes in the climate – and in sea levels – throughout history. A sudden rise in sea levels would certainly have been a catastrophe for ancient maritime cultures living along the coastlines of our planet just as it will be a catastrophe for those living in the low-lying areas of our modern culture. It appears that history does repeat itself, even if we have to wait 300 million years to see it happen.