Background
The authors note that the Intergovernmental Panel on Climate Change (IPCC; Houghton et al., 2001) "suggests that in the future the frequency of extreme temperature events and their magnitude will increase," which suggestion is implied by the IPCC to have significant negative consequences.

What was done
To investigate this suggestion as it might possibly apply to Argentina, Rusticucci and Barrucand derived trends of the mean, the standard deviation, and the extreme maximum and minimum daily temperatures over the period 1959-98 based on "a deeply quality-controlled stations database."

What was learned
In the words of the two Argentine scientists, "the variable that presents the largest number of stations with observed significant trends is the minimum temperature in summer, where positive trend values were found at many stations over 4°C (100 yr)^-1."  Concurrently, they report that "the maximum temperature in summer presented strong negative values of the same magnitude in stations located in central Argentina."  Hence, they conclude that "a large fraction of the area that yields most of the agricultural production of Argentina should result in reduced air temperature variability in the case of a warming climate, as is also shown by Robeson (2002) for the United States."

What it means
Contrary to the contention of the IPCC, real-world data from Argentina and the United States, as well as many other countries (see Temperature (Variability) in our Subject Index), demonstrate that global warming is generally accompanied by a decrease in temperature extremes, which for agriculture is a positive development.

References
Houghton, J.T., Ding, Y., Griggs, D.J., Noguer, M., van der Linden, P.J., Dai, X., Maskell, K. and Johnson, C.A.  2001.  Climate Change 2001: The Scientific Basis.  Cambridge University Press, Cambridge, UK

Robeson, S.  2002.  Relationships between mean and standard deviation of air temperature: Implications for global warming.  Climate Research 22: 205-213.