Heatwave and drought have caused severe damage to Russia’s grain crop. Yields are expected to fall by up to 40%. Russia announced a ban on wheat exports from August 15, causing a sharp rise in global grain prices.
How severe are conditions in 2010 compared to previous Russian droughts and heat waves?
The plot shows monthly growing season precipitation versus temperature anomalies for wheat croplands 1948-2010. A positive index value indicates high cropland precipitation or temperature. June and July this year are clear outliers.
Gridded 200km climate data (NCEP Reanalysis) were re-projected to an equal area projection and standardized. Then a weighted average over the harvested area for the year 2000 (data from C. Monfreda et al) was carried out.
 USDA World Agriculture Report, August 2010 http://www.fas.usda.gov/psdonline/circulars/production.pdf
 made using smoothScatter() base R graphics.
 raster map calculations using raster package by Robert J. Hijmans & Jacob van Etten.
 Monthly standardized precipitation and standardized temperature indices.