Laserfiche WebLink
Cooperative Institute for Research in Environmental Sciences <br />UNIVERSITY OF COLORADO BOULDER and NOAA <br />IPCC has concluded that warming results in: <br /> <br />•globally, drought-affected areas growing and expected to grow, <br /> <br />•droughts expected to be longer, more intense, more extensive. <br />PDSI hydrology model forced <br />by E0 based on T alone. <br />Dangers of T-based E0 parameterizations <br />Regional long-term trends in drought <br />BUT, comparing physically based E0 vs. T-based E0: <br /> <br />•E0 trends (30-year, observed) driven by wind, not T <br /> – Australia [Roderick et al., GRL 2007] <br />•PDSI-derived water balance trends vary significantly <br /> – Australia and NZ [Hobbins et al., GRL 2008] <br />•Little change in drought over the past 60 years: <br />o differences in E0 trends (T-based E0 +ve everywhere, physical only ~60%): global <br />dimming; stilling; VPD changes <br />o differences in signs of PDSI trend signs (T-based +ve over 7x physical-based area) <br />– global [Sheffield et al., Nature 2012] <br />Causal link in T-based drought analyses is often reversed: <br />increased T often results from drought, doesn’t force it.