Debate Over Climate Risks - Natural or Not

Debate Over Climate Risks - Natural or Not

NY times - April 16, 2009

In reporting on a news story about a newly revealed pattern of extreme droughts in sub-Saharan Africa, NY Times author, Andrew Revkin, found a firestorm of emails with disputes between scientists on the topic. A central dispute being on how scientists can best discuss risks and responses related to inherent, and dangerous, extremes of climate in a world increasingly fixated on how to limit global warming caused by human activity. So, the author has provided some of the experts from this email string in the form of a news article of which I’d like to discuss.
I agree (to the best of my knowledge) with all the expert comments. The Shanahan et al. Science paper is yet another piece of compelling evidence that the many paleo-records from every continent clearly show how the history of human civilization has been controlled by great droughts. Such mega-droughts have taken place in China, the Americas, Australia, the Middle East, SE Asia and Europe. Civilizations have fallen, deaths of millions of people resulted, great migrations occurred, and social and political unrest followed.
Let us not forget that the direct human impacts on drought are well known; overgrazing of farm animals, poor farming practices, clear-cutting of forests have exacerbated natural droughts. Many of the great tragedies of human history were drought caused and exacerbated by human reactions. Droughts are deadly events!
Today, most countries could not survive a mega-drought, certainly not the many struggling nations that exist at marginal levels, such as sub-Saharan Africa. The global population explosion of the 19th and 20th Centuries has resulted in growing pressures on food, water and public health. We can’t migrate our way out of mega-droughts; there are too many of us and we are irreversibly wedded to our massive infrastructures.
A mega-drought today would be a human tragedy of unprecedented horror.
Even if we can control and reduce our fossil fuel thirst, our collective future is in dire peril if population is not constrained. A mega-drought with a global population of 9 billion would be apocalyptic.
With new evidence from wood samples revealing six ‘mega-droughts’ in West Africa in the last 3,000 years, this is a heated science debate topic. To read more on the droughts in Africa and there impact visit http://dotearth.blogs.nytimes.com/2009/04/16/debate-over-climate-risks-natural-or-not/.