In each hundred-thousand year period, there is an ice-age that lasts about ninety thousand years and a warm interglacial period that lasts about ten thousand years. We are at present in a warm period that began twelve thousand years ago, so the onset of the next ice-age is overdue.
Special order items
If human activities were not disturbing the climate, a new ice-age might already have begun. We do not know how to answer the most important question: do our human activities in general, and our burning of fossil fuels in particular, make the onset of the next ice-age more likely or less likely? On the one side, we know that the level of carbon dioxide in the atmosphere was much lower during past ice-ages than during warm periods, so it is reasonable to expect that an artificially high level of carbon dioxide might stop an ice-age from beginning.
On the other side, the oceanographer Wallace Broecker [Broecker, ] has argued that the present warm climate in Europe depends on a circulation of ocean water, with the Gulf Stream flowing north on the surface and bringing warmth to Europe, and with a counter-current of cold water flowing south in the deep ocean. So a new ice-age could begin whenever the cold deep counter-current is interrupted.
The counter-current could be interrupted when the surface water in the Arctic becomes less salty and fails to sink, and the water could become less salty when the warming climate increases the Arctic rainfall. Thus Broecker argues that a warm climate in the Arctic may paradoxically cause an ice-age to begin.
The Page-Barbour Lectures at the University of Virginia | Awards | LibraryThing
Since we are confronted with two plausible arguments leading to opposite conclusions, the only rational response is to admit our ignorance. Until the causes of ice-ages are understood, we cannot know whether the increase of carbon-dioxide in the atmosphere is increasing or decreasing the danger.
This small thickening, sustained over thousands of years and spread over the vast expanse of these sectors of Antarctica, corresponds to a very large gain of ice — enough to outweigh the losses from fast-flowing glaciers in other parts of the continent and reduce global sea level rise. You are commenting using your WordPress.
You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email. Notify me of new posts via email. This site uses Akismet to reduce spam. Learn how your comment data is processed. Skip to content. Macbooks All In Ones 2 in 1 Laptops.
Home Theaters Headphones. Towels Sink Urinals. Tool Sets Bathroom Accessory Sets.
The Best of "In It"
Close to Ceiling Lights Pendant Lights. Body Lotions Face Creams. Tents Accessories Lights Camping Bed.
- Hunter and Hunted. Relationships between Carnivores and People.
- Dyson's heretical thoughts on climate change and science | ClutchFans?
- Featured channels;
Billiard Fishing Toss Games. Business Writing Skills.
A Many-colored Glass
Graphic Novels Comic Strips. My Wishlist. Know about stores. Products of this store will be shipped directly from the US to your country. Products of this store will be shipped directly from the UK to your country. Products of this store will be shipped directly from China to your country.
Series: The Page-Barbour Lectures at the University of Virginia
Products of this store will be shipped directly from Japan to your country. Products of this store will be shipped directly from Hong Kong to your country. Shop By Category. My Orders.