The Economist provides a nice overview discussing the significance of the new World Bank Potsdam Institute for Climate Impact Resarch report, which assigned recent extreme summer temperatures to climate change. This study concluded that since the 1980s, corn production is 3.8 percent lower and wheat production is 5.5 percent lower than it would have been without climate change.
The Economist then contrasts this conclusion with a Nature study that pointed out that the Palmer index, which uses precipitation and temperature data to calculate evaporation rates and thus moisture levels in the soil, is too simplistic.
All things considered, the scientists are still working on data collecting and interpretation and that is improving all the time. So far, none of the models have been able to include all of the factors that influence droughts to be able to accurately make projections about future droughts beyond a medium level of confidence.
Be leery of any reports that tell you otherwise.
Research program on Climate Change, Agriculture and Food Security
New “Big Facts” Site
Big Facts – Where agriculture and climate change meet
CGIAR’s climate research department came out with a new “grand central” site for agriculture and climate change. This page from the site focuses on climate change’s impact on crops. If you read through the page, you will see why covering this topic is so complex — because there are so many variables.
One quote from the page is this:
Uncertainties in projections limit the value of precise numerical forecasts of future crop yields; all projections of future crop yields and associated changes in food prices should be treated with considerable caution (Challinor et al. 2009).
Also included on this crops page is the subject of dealing with new and increasing numbers of plant pests:
In current production areas, the likely challenge of pests and diseases will mean that an increased focus on integrated management systems, especially host plant resistance and biological control, is essential. Pests and disease that were once minor problems can turn into major constraints and change their range of distribution with climate change. For example, projections illustrate these effects for three major cassava pests: the mealybug, the cassava green mite and the whitefly (Herrera et al. 2011).
The summary at the top of the crop impacts page includes this, “the overall impact on grain is negative—the potential yield loss is about 5 percent for each degree Celsius of global warming.”
CGIAR’s “Big Facts” site covers climate impacts on water, crops, livestock, fisheries, forests, and food security.
International Conference on Food Security in Dry Lands, Doha
The International Conference on Food Security in Dry Lands was held in Doha, Qatar earlier this month, titled “Strategies for Combating Climate Change in Drylands Agriculture”.
For anyone interested in global food security and in solving future agricultural challenges in the most problematic areas, the report is well worth your time.
I particularly liked the following part which tells us some of the accomplishments from efforts to improve production in dryland regions through the use of science and technology and the sharing of information:
Already, scientists have produced some convincing results:
More than 880 new varieties have been released for cultivation, generating annual benefits worth US$850 million.
• Dryland researchers have developed synthetic wheat varieties that can produce 2.5 tonnes per ha with just 220 mm of water.
• Between 2005 and 2007, Syria turned from being a wheat importer to a wheat exporting country with the help of new improved plant varieties, and supplemental irrigation – which targets the critical period in crop growth – and inputs.
• In Sudan south of Khartoum, an irrigated heat-tolerant variety is enabling farmers to grow wheat in an area where temperatures were too high and the season too short for growing traditional varieties.
• In Bangladesh, new lentil varieties combine high protein levels with micronutrients such as zinc and iron.
• A drought tolerant variety of chick pea introduced in Turkey had such strong resistance that it was able to withstand the searing temperatures and rainfall scarcity of the 2007 drought. The ‘Gokce’ variety is now used for about 80% of the country’s chickpea production. With a yield advantage of 300 kg/ha over other varieties and world prices of over US$1000/t, this variety brought in an additional US$165 million for Turkish farmers in 2007 alone.
The report goes on to describe how local entrepreneur-produced no-till seeders are being manufactured to advance mechanization of agriculture in Iraq and Syria. These locally produced machines cost a small fraction of similar, imported equipment.
The report includes the above FAO graph which puts the population growth as related to food needs into a rather shocking graphic perspective showing how much cereal would be desired for import by these dryland regions in 2030. This helps us to understand why food consumption of wheat is increasing more than any other commodity, and why yesterday’s big wheat genome announcement is welcomed.
(To see a PDF report of the Synthesis of dialogues and evidence presented at the International Conference on Food Security in Dry Lands, Doha, Qatar, November, 2012: bit.ly/WytgcL )
This week, the United Nations released a new report warning of the possibility that permafrost thawing might ultimately account for up to 39 percent of total greenhouse emissions, and once the process begins in a couple of decades (and continues for several centuries), it will operate in a feedback loop which will further accelerate permafrost warming.
Ice Melt Study
A new study is out reporting that the ice sheets in Greenland and Antarctica are losing three times as much ice as twenty years ago. The ice melt has contributed perhaps a half-inch to a rising sea level. But sea levels are expected to rise 40 inches in the next 90 years mostly from expansion due to warmer temperatures. Extracting more groundwater for irrigation over the next century may also add 10 centimeters to sea level by 2100.
U.S. Topsoil Moisture is Concerning
The above map from NCDC NOAA compares topsoil moisture from Oct 7, 2012 to the ten year mean.
In the key agriculture producing state of Iowa, after a wetter October, November has seen only half of normal precipitation. Two-thirds of Iowa’s topsoil is moisture-deficient and 94 percent of its subsoil lacks adequate moisture.
Current Drought Map
The current drought monitor map out of the University of Nebraska shows that Nebraska is ground zero for dryness.
The USDA reported that unfavorably dry weather caused crop conditions to further deteriorate last week. Overall, 33 percent of the winter wheat crop was reported in good to excellent condition, 19 percentage points below the same time last year. In Nebraska, half of the winter wheat crop is in poor or very poor condition.
NOAA: October Set New Records
The January-October period was the warmest first ten months of any year on record for the contiguous United States.
January-October 2012 was the 16th driest such period on record for the contiguous U.S.
The November 2011-October 2012 period was the warmest such 12-month period on record for the contiguous U.S., with an average temperature of 55.2°F, 3.2°F above the long-term average. This 12-month temperature average was the sixth warmest of any 12-month period on record for the contiguous United States. The seven warmest 12-month periods have all ended during 2012.
The average combined global land and ocean surface temperature for October 2012 tied with 2008 as the fifth warmest October on record.
The globally-averaged land surface temperature for October 2012 was the eighth warmest October on record, at 0.92°C (1.66°F) above average. The globally-averaged ocean surface temperature tied with 2004 as the fourth warmest October on record, at 0.52°C (0.94°F) above average.