The Mediterranean has been called the cradle of Western Civilization, and we now know that the Mediterranean is also the key to ice-age climate change. Recent research shows that, rather than climate temperature variations, it is the moisture supply to the glacial regions that determines the glacial cycles. The amount of moisture carried by storms to glacial regions is sensitive to the temperature and salinity of the northern North Atlantic. The salinity of the northern North Atlantic is influenced by the salt content of the Mediterranean Sea by way of its salty outflow at Gibraltar. The salty outflow is modulated by the strength of the African summer monsoon. The monsoon strength changes with the variation of received solar energy caused by alterations in the tilt of the earth's polar axis and by the movement of the summer season to different points on the earth's orbit around the sun. The orbital factors therefore influence glacial-ice volume and climate by way of the salinity variations of the Mediterranean Sea.

In easy historical steps, this new book describes the efforts of scientists to understand why ice ages occur, and the evidence for the role that the Mediterranean Sea plays in the grand sequence of climate change over the last three million years. You will see how the orbital theory of ice ages advocated by Croll and Milankovitch passed through cycles of scientific acceptance and rejection leading to the modified version put forth in this book, a version that is in good agreement with the geological records.

With this better understanding of how the climate system works, we can predict the next significant climate change. Despite the greenhouse warming caused by the increasing carbon dioxide in the atmosphere, or partly because of it, the onset of new large-scale glaciation in northeastern Canada may occur within the next quarter of a century. This introduction to a new ice age is likely when the last of the polar pack ice on the Arctic Ocean is lost as the salinity of the Arctic Ocean increases. The loss of the pack ice has been in progress for the last three or four decades, during which the ice has thinned by almost 50%.

The new model of climate change is firmly grounded on the geological record of past climate changes and on the applied physics of oceanic and atmospheric circulation. The book has 128 journal references, which include research results from the author's own 30 years of activity in the search for the causes of climate change. The 65 illustrations clarify the climate concepts as they are developed throughout the book, and make the book an easy read for anyone with an interest in how the world's climate system works.