<table> <tr valign="top"> <td> How do the heat and dryness fit into historical trends for the region? A soon to be published report titled the "Southwest Climate Assessment" (Hoerling et al, 2012) can be used as a guide to answer these questions. Here are some findings: === Temperature and Precipitation === *The decade 2001–2010 was the warmest and the third driest in the Southwest of all decades from 1901 to 2010 *Average annual temperature increased +0.9°C +/- 0.3°C over the Southwest during 1901–2010, while annual precipitation experienced little change. === Streamflow === *Streamflow totals in the four major drainage basins of the Southwest were 5% to 37% lower during 2001–2010 than their average flows in the twentieth century. *Streamflow and snowmelt in many snowmelt-fed streams of the Southwest trended towards earlier arrivals from 1950-1999, and climate science has attributed up to 60% of these trends to the influence of increasing greenhouse-gas concentrations in the atmosphere. === Paleoclimate Context === *The period since 1950 has been warmer in the Southwest than any comparable period in at least 600 years, based on paleoclimatic reconstructions of past temperatures. *The most severe sustained droughts during 1901–2010 were exceeded in severity and duration by several drought events in the preceding 2000 years, based on paleoclimatic reconstructions of past droughts. </td> <td width="400"> {{image popup="true" entry="250f46fb-040b-4ff9-9d64-8d48c0dd5ecb" popupcaption="over" width="400" link="false"}} <p> <i>{{description entry="250f46fb-040b-4ff9-9d64-8d48c0dd5ecb|Observed Temperature/Precipitation Trends - 1901-2010" }}</i> </td> </tr> </table>