Abstract/Description or Keywords |
A comprehensive review of paleoenvironmental data provides the basis for evaluating natural climate variability in southwestern British Columbia. Key indicators of past changes include paleolimnological, paleobotanical, glaciological and dendroclimatological evidence. Lacustrine sediments record the rapid transition from a glacial to an interglacial climate 12,500 to 9000 14C yr BP. Peak summer temperatures (about 3 °C warmer than present) and minimum precipitation were recorded ca. 9000 to 7000 14C yr BP, but were likely accompanied by winter temperatures colder than today. Mid-Holocene cooling appears to have occurred sooner on the coast of British Columbia (~ 5000 14C yr BP) than in the southern interior where summer temperatures gradually declined ca. 7000 to 3000 14C yr BP, as wetter conditions and a stronger Aleutian low developed. Many glacial advances have been recorded in the past 3500 years, with most glacial maxima dating to the mid 19th century. A general glacial retreat has accompanied recent warming. |