between the Recent Droughts and Global Warming
by Ben Luce, president, NMSEA
article in Science Magazine called “The Perfect Ocean for Drought”, by National
Oceanic and Atmospheric Administration researchers M. Hoerling and A. Kumar
(Science, Vol. 299, p. 691-694), presents the first strong case that the
droughts of 1998-2002 are indeed highly anomalous and consistent with global
warming caused by emission of greenhouse gases. This is an important scientific
milestone, and underlines the urgency for a dramatic reduction in CO2 emissions.
official announcements of Hoerling and Kumar's work (which we preserved in our
archive) can be found here:
are some highlights of the study:
- The 1998-2002 droughts
were extreme and widespread: As little as 50% of the annual average
precipitation fell during this period in an extensive swath of mid-latitudes
spanning the US, the Mediterranean, Southern Europe, and Southwest and
Central Asia (so our drought is part of something much larger, and much more
- Global Warming appears to
be a major factor: The droughts appear to be caused by the simultaneous
occurrence of two events: Unprecedented warm sea surface temperatures in the
Western Pacific, and an unusually strong (but not unprecedented) "La
Nina" event, meaning cold sea surface temperatures in the Eastern
Pacific. The unprecedented warming in the Western Pacific is, besides being
statistically unlikely and unprecedented, highly consistent with greenhouse
gas induced warming.
- The results suggest an
“increased risk” for further “severe and synchronized drying of the
mid-latitudes” if these anomalous sea surface patterns persist.
reinforces the growing awareness that global warming is not something off in the
future – its already well under way and having costly impacts.
introduction to the science and issues surrounding global warming, see the Global
Warming Section of NMSEA's Energy Physics Primer.