Impact of historical land cover change on daily indices of climate extremes including droughts in eastern Australia

Abstract

There is growing scientific evidence that anthropogenic land cover change (LCC) can produce a significant impact on regional climate. However, few studies have quantified this impact on climate extremes and droughts. In this study, we analysed daily data from a pair of ensemble simulations using the CSIRO AGCM for the period 1951–2003 to quantify the impact of LCC on selected daily indices of climate extremes in eastern Australia. The results showed: an increase in the number of dry and hot days, a decrease in daily rainfall intensity and wet day rainfall, and an increase in the decile‐based drought duration index for modified land cover conditions. These changes were statistically significant for all years, and especially pronounced during strong El Niño events. Therefore it appears that LCC has exacerbated climate extremes in eastern Australia, thus resulting in longer‐lasting and more severe droughts.