onestep said:
and lest we not forget the dire prediction that everyone believed in the late 70's / early 80's... "global cooling, the upcoming ice age".
(i'm not sure if this was before or after the dire prediction that we would run out of oil by the year 2000)
oh yeah, and what ever happened to that hole in the ozone?
Onestep
My guess is that Onestep is pulling our legs on these three items.
Yes, there was some talk in the 1970s about the Little Ice Age (about 1450-1850 A.D.) being a precursor for the next full glaciation, as our current interglacial epoch (named the Holocene) is due to end in the next few millennia, if not few hundred years (based on astronomical cycles related to the Earth's position relative to the Sun). However, based on deep-sea sediment core and Antarctic ice core records of paleotemperatures spanning the past three+ million and 850,000 years, respectively, we know that full Northern Hemispheric glaciations take hundreds to thousands of years to build up (past rapid climate change events such as the Younger Dryas cold event of 13000 to 11700 years ago aside), or much longer than human time scales, which are now so vulnerable to current global warming and sea-level rise. Dr. Bill Ruddiman has proposed a really neat hypothesis that humans have been impacting climate for the past 8000 years (not just the past 150 years), and are probably responsible for delaying the next glaciation cycle, summarized in his 2005 book at the link below (which is very readable). Ruddiman also suggests in this book that pandemics over the past millennia have periodically cooled global temperature, so bring on the bird flu!
http://www.amazon.com/Plows-Plagues...ef=sr_1_1/105-1210301-9362847?ie=UTF8&s=books
In the late 1950s, Dr. M. King Hubbert, one of the most famous geologists of the past 100 years, predicted that oil and gas production in the United States would peak (not run out, but peak) in the late 1970s, which turned out to be right on the mark. More recently, Dr. Ken Deffeyes (the geologist who accompanied John McPhee on a road trip across I-80 westward from Salt Lake City leading to McPhee's classic book "Basin and Range") used the same methodologies as Hubbert to predict that global oil production would peak (again not run out, but peak) between 2005 and 2010, which certainly looks like it could become true. So, in the best case scenarios, we probably have less than 50 to 100 years of oil and gas reserves remaining, with few viable economic alternatives at the moment (link to Deffeyes' fine book below).
http://www.amazon.com/Beyond-Oil-Vi..._bbs_sr_1/105-1210301-9362847?ie=UTF8&s=books
And, finally, the holes in the stratospheric ozone layer are still there, the one over the high latitudes of Southern Hemisphere more severe than the one in the North. However, thanks to the Montreal Protocol in 1987, an international treaty signed even by the U.S., we have sharply reduced the global production and release of chlorofluorocarbons (CFCs), the main culprit in stratospheric ozone production (CFCs are also greenhouse gases, albeit never as big a player as carbon dioxide and methane), and at least the ozone holes are not becoming appreciably larger (it will take another few decades for stratospheric ozone to recover completely). Atmospheric chemists Mario Molina and Sherwood Rowland won a Nobel Prize for their scientific discovery of stratospheric ozone destruction, and fortunately we listened to them and responded, without any major disturbance to the global economy. For those of us who enjoy hiking outside (most on this board?), we should be happy that our chances of getting skin cancer are now less than they would have been without the Montreal Protocol. The same is now true with our response to the warning about global warming, but will we listen and respond?
Dr. D.
