Impacts of Increased Climatic Variability

Recent Examples

The Hot August in France in 2003


France is a major exporter of wheat, maize, barley and potatoes to Europe and the Middle East. In 2003 it experienced the hottest summer since the beginning of the historic measured record. Each blue line in the graph below indicates the average summer temperatures for each year since the late 1800’s. The 2003 event is clearly exceptional, resulting in agricultural losses exceeded four billion Euros. The production of fodder, maize and potatoes, all of which are very sensitive to heat, declined between 20-60%.

The Hot August in Russia in 2010


Russia which is the 5th largest wheat exporter experienced a similar hot summer in 2010 and as shown in a similar graph, this drought was again most unusual based on measured historic records.

Due to massive decline in wheat yields as result of the drought, Russia suspended all wheat exports and as shown in the graph above there was an immediate increase of up to 60% in the global commodity food price index. Usually food prices are highly influenced by the rise in oil prices and the food index soared during the financial crisis of 2008, when the oil prices reached $138/barrel). However, as is shown in the lower part of the graph, the food price index in September increased by about 50% while the oil prices stayed the same. The September increase can therefore directly be attributed to the shortage in global wheat supply as a result of Russia being unable to export wheat.

Australia’s Drought and Floods 2002-2012

Australia is well known as a key food exporter. It is the largest beef exporting country, third in wheat and fourth barely, rapeseed and cotton exports. The Murray Darling River Basin produces 40% of the food in Australia and between 2002 and 2009 it experienced one of the most intensive droughts in recent memory. The drought peaked in 2003 and more dramatically in 2007 and the results were dramatic. Water supplies were at an extremely low level and as seen in the discharge graph the river ceased to flow during the peak of the drought in 2007. The impact of this drought on food production is seen in the following graph, indicating that wheat and rice production was reduced by half and even the wine industry was heavily impacted. Again this had a dramatic effect on global food trade contributing to significant reduction in wheat and rice export. The drought alone was not the only reason why there was such an impact on food production. The 1950-1990 period was significantly wetter than the previous 40 year period and at that time Australia embarked on a widespread construction of dams in the Murray system and over-allocated water entitlement for irrigation. This rapid irrigation expansion is thought to have exacerbated the effect of the drought.

What makes this Australian case even more alarming is that in 2011 and in 2012 the SW-Queensland area experienced some of the worst floods on record after a period of extensive rainfall of 1200 mm over 51 days.

According to Craik and Cleaver (2011) the following five reasons were responsible for the severity of the impact of the drought:

  1. Rapid expansion in irrigation water entitlement during the 1950 to 1990, when rainfall was significantly higher and large storage dams were constructed
  2. Very hot temperatures that increased evapotranspiration, three of the last five years being the hottest in 100 years
  3. Changing rainfall patterns with significant lower autumn rain
  4. 2006-07 inflow into the river system was the lowest on record.
  5. Exceptionally dry period lasting over a two year period.

  1. Rapid expansion in irrigation water entitlement During the 1950 to 1990, when rainfall was significantly higher and large storage dams were constructed
  2. Very hot temperatures that increased evapotranspiration. Three of the last 5 years being the hottest in 100 years
  3. Changing rainfall patterns with significant lower autumn rain
  4. The 2006.07 inflow into the river was the lowest on record.
  5. The exceptionally dry period lasted over a two year period.

The Mississippi Flood in 2001 and the Texas Drought of 2011.

The USA is the largest food exporter and 2011 proved to be one of the most unusual years in the Mississippi River basin. In May 2011 all the headwater stations were  experiencing extreme flood conditions while at the same time all streams in the southern part of the Mississippi were in an exceptional drought stage in the summer of 2011. This is best shown in the USGS map that illustrated the average 28 day streamflow at all gauging stations compared to the historic streamflow during the same time of the year. The hot and dry conditions leading to an extended drought which started in March reached a peak in August and persisted well into December. According to the USDA Drought monitor (http://droughmonitor.unl.edu/) Texas was in an exceptional drought. Subsequent analysis showed that this was the hottest and driest year since 1895.

Texas produces 40% of the nation's cotton and sorghum and is home to 15% of the US cattle USDA, 2011). The drought was so severe that for the first time in recent years the cattle population in Texas was significantly been reduced by slaughtering many animals and moving 250000 cattle to Nebraska where sufficient food sources where available.

Number of Cattle and Calves in Texas (2000-2012)

It is of course too early to determine the impact of both the flooding events in the headwaters and the drought in Texas because export data is not yet available. However beef prices in the USA increased from 178.2 cents/lbs in June 2011 to 195 cents/lbs in March 2012.

Flooding in Thailand in June 2012.

Thailand is a major rice producing nation and is responsible for about 1/3 of globally exported milled rice. A particularly heavy monsoon rain occurs from May to October which was 140-190% above the 30 year mean, as shown in the graphs below. This caused extreme flooding in a wide region around Bangkok and had significant impacts on food production, the impact of which is still being determined.

Thailand 2011 Flood

The US Drought in the Mid-West in 2012

The US Mid-West consists of 12 States (Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota,  Missouri, Nebraska, Ohio, North and South Dakota and Wisconsin) and has some of the best soil and climatic conditions in the world to produce corn and soybeans. In 2011 this region produced 80 % of all corn and 81% of all soybeans in the USA. As shown in the figures below 19 states reported record annual temperatures in 2012 and 1/3 of the US population experiences more than 10 days of temperatures above 38 degree centigrade.
 
In 2012 all 12 Mid-West states had above average temperatures for every month from January to August and the drought had a significant impact on crop production. The data is still preliminary, but the USDA is estimating a yield reduction of 13% in corn and 14% in soybeans. The extent of the drought in July is shown below. Since the US plays such a large role in global export the impact of the production declines from the dought is already evident globally by a 15% increase in the FAO cereal price index in August 2012 (see graphs below).

Comparison of US Drought Between 2011 and 2012

In 2011 the drought was more severe but concentrated over Texas, while the drought in 2012 was less severe but much more widespread. NOAA reported that 1283 stations had more than 10 days of temperatures greater than 38 degree but this increased to 1832 Stations with more than 38 degree celsius in 2012. Overall 2012 was the warment year since consistent record keeping started in 1985.See NOAA's comparison below.

Temperature Comparison 2011-2012

Risk and Vulnerability

The following maps by the USDA show how vulnerable the global food supply has become. As indicated before, the USA produces 49% of all corn and 45% of all soybeans that are exported globally. In 2011, seven adjacent states (Ohio, South Dakota, Indiana, Minnesota, Nebraska, Illinois and Iowa) produced 74% and 66% of the annual US production. This clearly shows how vulnerable the global food export market has become because if a major climatic event hits these seven states, the risk to the global food supply is enormous.

Climatic Events and Global Food Prices

Tracking the food price index shows that all these climatic event had a significant impact on global food prices. This analysis is complicated, because changes in energy prices also impact food prices (see graph below). However, what this graph shows is that the global food supply is becoming much more volatile because we rely on relatively few countries that are major food exporters and any unusual climatic event in these exporting countries has an  immediate impact on the global food prices.
The changes in the cereal price index shows how the recent droughts have impacted global cereal prices, because each of the countries affected by the droughts are major cereal exporters. A similar trend is also shown in the meat price index, but this interpretation is a bit more complex because many of the drought stricken countries are also large meat and feed crop exporters, and there is usually a greater delay in meat price increases because the feed has to be consumed by the livestock before we notice a change. As shown above the USA is the largest global exporter of corn and soybeans, which are primarily used for animal feed. It will be interesting to track the changes in the coming months to see the delayed effect from the 2012 drought in the MId-West in the USA.