Palaeo-climate change

24 Jun 2011

A story at ... scientists are taking samples of soil that formed up to 20,000 years ago to find out what was growing in the Hackensack Basin from then until now. The basin was formed by a glacier in the last Ice Age and when it shrank back a lake formed there. It seems that the 20,000 years figure might be somewhat loaded as the lake itself did not drain away or dry up until some point between 10,000 and 7,000 years ago, possibly at the onset of the Mid Holocene Warm Period - 8,000 years ago. If so the lake may have drained as a result of a change in the geoid (but see earlier posts) but ignoring ideas such as that, apart from lake sediments the soil being investigated, it is hoped, will allow people to evaluate the climate by what was growing there. For example, the white cedars found there when the Europeans arrived actually only go back 600 years and are associated with the Little Ice Age climatic conditions. The pattern of previous climate in northern USA will be quite interesting from a number of factors but the research has an obligatory AGW adjunct - so read between the lines.

Meanwhile, reports on a paper in the June 19th Nature Geoscience that has found no palaeo evidence of co2 sparking global warming in the past in a study of the North Atlantic basin. In fact, past sudden shifts in climate were caused when sea ice cooled the North Atlantic waters (the so called Heinrich and Dryas events) which conveniently ignores the mechanism of what set in motion the weather that led to iceberg fans on the ocean bed. The fact that lots of icebergs coincided with cold weather or climate is a symptom and not necessarily at the heart of things - but at least there is no co2 dream machine at work (in this paper at least). In addition, the research involved a lot of computer simulation, with grey matter taking a back seat and a preponderance on the data actually fed into the machine. The idea, presumably, was to show that climate could change as a result of ocean circulation redistribution of cold water pouring into the North Atlantic as a result of lots of icebergs - and this is what the simulation proved. It could (and see also which has the same story).

Somewhat more positive is a story at where we are informed of plans to build a belt of forest and lush vegetation 15km wide from Senegal through Mali, Niger, Nigeria, Chad, Sudan, to Ethiopia, coast to coast for 4750 miles along the Sahel, in an attempt to hold back the growth of the Sahara desert. Not just as a result of arid conditions via low precipatation but from the encroaching sands that envelope what is cultivatable land. In Senegal the green wall is already in progress - the idea is to get other countries to join in.