Saturday, September 15, 2012

Threat to global food supply makes comprehensive action imperative

Climate change is strongly affecting the Arctic and the resulting changes to the polar vortex and jet stream are in turn contributing to extreme weather in many places, followed by crop loss at a huge scale.

The U.N. Food and Agriculture Organization (FAO) said in a September 6, 2012, forecast that continued deterioration of cereal crop prospects over the past two months, due to unfavourable weather conditions in a number of major producing regions, has led to a sharp cut in FAO’s world production forecast since the previous report in July.

The bad news continues: Based on the latest indications, global cereal production would not be sufficient to cover fully the expected utilization in the 2012/13 marketing season, pointing to a larger drawdown of global cereal stocks than earlier anticipated. Among the major cereals, maize and wheat were the most affected by the worsening of weather conditions.

Below an interactive image with the FAO Food Price Index (Cereals), up to and including August 2012.


Apart from crop yield, extreme weather is also affecting soils in various ways. Sustained drought can cause soils to lose much of their vegetation, making them more exposed to erosion by wind, while the occasional storms, flooding and torrential rain further contribute to erosion. Higher areas, such as hills, will be particularly vulnerable, but even in valleys a lack of trees and excessive irrigation can cause the water table to rise, bringing salt to the surface.

Fish are also under threat, in part due to ocean acidification. Of the carbon dioxide we're releasing into the atmosphere, about a third is (still) being absorbed by the oceans. Dr. Richard Feely, from NOAA’s Pacific Marine Environmental Laboratory, explains that this has caused, over the last 200 years or so, about a 30% increase in the overall acidity of the oceans. This affects species that depend on a shell to survive. Studies by Baumann (2011) and Frommel (2011) indicate further that fish, in their egg and larval life stages, are seriously threatened by ocean acidification. This, in addition to warming seawater, overfishing, pollution and eutrification (dead zones), causes fish to lose habitat and is threatening major fish stock collapse.

Without action, this situation can only be expected to deteriorate further, while ocean acidification is irreversible on timescales of at least tens of thousands of years. This means that, to save many marine species from extinction, geoengineering must be accepted as an essential part of the much-needed comprehensive plan of action.

Similarly, Arctic waters will continue to be exposed to warm water, causing further sea ice decline unless comprehensive action is taken that includes geoengineering methods to cool the Arctic. The image below shows the dramatic drop in sea ice extent (total area of at least 15% ice concentration) for the last 7 years, compared to the average 1972-2011, as calculated by the Polar View team at the University of Bremen, Germany. This illustrates that a firm commitment to a comprehensive plan of action can now no longer be postponed.


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