GPHY 102 Lecture Notes - Lecture 10: Mountain Pine Beetle, General Circulation Model, Permafrost

• School: Queen's University
• Department: Geography
• Course: GPHY 102
• Professor: Dr.Trezino

Document Summary

Recall: global energy system (cid:149) counter-radiation and the greenhouse effect keeps average earth surface temperature >0 degrees. (cid:149) amount depends on amount of water vapour and co2 in atmosphere. Carbon dioxide (co2) (cid:149) preindustrial atmospheric co2 levels were ~ 280 parts per million (ppm). (cid:149) co2 levels are currently 397 ppm (noaa. 2012) (cid:149) various projections for future concentrations, all significantly greater than 500 ppm. Other greenhouse gases such as methane, chlorofluorocarbons, tropospheric ozone and nitrous oxides also contribute. http://www. esrl. noaa. gov/gmd/c cgg/trends/history. html. Annual / five-year mean temperature changes (base period 1951-1980). Three latitude bands (30%, 40% and 30% of the global area). Five-year global temperature anomalies from 2008 to 2012 (compared to 1951-1980 base period average) Nasa goddard institute for space studies (giss) http://data. giss. nasa. gov/gistemp/graphs_v3/ Increased amounts of tropospheric aerosols (increased scattering) Land-cover alteration (increased albedo) (cid:149) natural variations. Volcanic aerosols have had both warming and cooling effects. (cid:149)