By JR on Thursday, September 22, 2011
Greenies claim that warming is global and that one of its effects is more extreme weather. So shouldn't we expect all that in Australia too?
Discussing: "Li, F., Roncevich, L., Bicknell, C., Lowry, R. and Ilich, K. 2011. "Interannual variability and trends of storminess, Perth, 1994-2008". Journal of Coastal Research 27: 738-745.
Among the highly publicized changes in weather phenomena that are predicted to attend global warming are increases in the frequency and severity of various types of storms. Storms are a concern of the residents of any coastal city, as high winds, water surges and high-energy waves carry the potential for damage via flooding and erosion.
What was done
Citing "unprecedented public concern" with respect to the impacts of climate change, Li et al. (2011) set out to examine the variability and trends of storminess for the region of the Perth metropolitan coast of Australia. To do so, they conducted an extensive set of analyses using observations of wave, wind, air pressure, and water level over the period 1994-2008. The results of their analysis, in their view, should serve "to validate or invalidate the climate change hypothesis" that rising CO2 concentrations are increasing the frequency and severity of storms.
What was learned
As shown in the figure below, all storm indices showed significant interannual variability over the period of record, but "no evidence of increasing (decreasing) trends in extreme storm power was identified to validate the wave climate change hypotheses for the Perth region."
Annual storm trends defined by (a) stormy hours and (b) number of storm events, as determined by wind speed, significant wave height, non-tidal residual water level, and mean sea level pressure. Adapted from Li et al. (2011).
What it means
As the earth experienced what the IPCC has characterized as unprecedented warming over the past two decades, Perth has not experienced an increase in storm trends. Thus, the results of this study lean toward invalidating the hypothesis of a CO2-induced influence.