The authors assert the frequency of El Ni o has been altered by human changes to the atmosphere s greenhouse effect. The first thing to note is that since 1895 there is no long-term trend in October March precipitation. The record begins in that year. Since 1910, however, there has been a statistically-significant precipitation increase . Following the researchers logic, this should be salutory for toads.
Toads are sensitive to climate, period.
Complex causes of amphibian population declines. Pounds, J.A., 2001. Climate and amphibian declines. The historical time series of October through March precipitation in Oregon s Cascade Mountains shows that climate varies an time scales from years to decades, and probably even longer. However, since 1895, there has been no statistically-significant trend.