Posted at 1:11 PM on November 16, 2007
by Craig Edwards
While the big weather news in the USA is the drought in the southeast and the relatively mild month of November, globally, a tropical cyclone devastated Bangladesh on Thursday. More than a thousand perished from the storm that struck with winds of 150 mph.
Earlier this month tens of thousands were forced to flee their homesteads in Mexico as four days of heavy rains flooded the region.
Heavy rains in Mexico
For both the 2006 and 2007 tropical storm season the US coastal areas were spared. Weren't there dire predictions by experts that the warm ocean temperatures would spawn more frequent and violent hurricanes?
My goal is simple to deliver Minnesotans an accurate forecast out the next five days. Predicting an entire season is still a conundrum for the most talented meteorological experts.
The updated NOAA Climate Prediction Centers outlook for the winter of 2007-2008 was released on Thursday. Here's the latest for your coffee shop banter.
Posted at 3:03 PM on November 16, 2007
by Mark Seeley
Every now and then a piece of significant research falls through the cracks and is not noticed by the wider community. Such may be the case of a paper released earlier this year by Christopher Scholz and 18 other co-authors. It appeared in Proceedings of the National Academy of Science.
Many anthropological studies of early humans (Homo sapiens) trace maternal lineages back to South and East Africa. Using DNA techniques, modern human ancestry is clearly traceable to this area before 130,000 years ago.
Climate studies from African lake sediments (Tanganyika, Malawi, and Bosumtwi) reveal that climate variability and especially aridity were quite severe during the period from 135,000 to 75,000 years ago. Maintenance of a sizable population of human beings on the African continent would have been a formidable task in such a harsh and highly variable climate. Severe droughts that were decades long severely limited the terrestrial and aquatic food supplies, as well as fresh water supplies.
But a climatic shift away from these highly variable and arid conditions took place about 70,000 years ago, and the African continent became much wetter and a good deal more stable from year to year. This is coincident with detected rapid expansion of early modern human populations, not only across Africa but out of Africa.
Blessed with more abundant food supplies and waterways to travel, it seems that climate change at that time opened the door of opportunity for the human race to explore new territory, and thus began the spread to the Mediterranean, then Asia and Europe. The hypothesis proposed by the authors is that climate change was the trigger for this!
You can read more on megadroughts and early human origins here(1 Comments)