BIO1042 Lecture Notes - Lecture 20: Ocean Current, Aust, Food Chain
5 Oct 2018
School
Department
Course
Professor
Document Summary
Land & oceans release heat (infrared radiation) into atmosphere. H2o (cid:448)apou(cid:396), co2 & t(cid:396)a(cid:272)e gases* i(cid:374) lo(cid:449)e(cid:396) at(cid:373)osphe(cid:396)e a(cid:271)so(cid:396)(cid:271) so(cid:373)e of this (cid:396)adiatio(cid:374). Ea(cid:396)th"s surface remains warm: * concentrations of greenhouse gases are increasing. Why is the planet warming: different molecules bounce and redistribute radiation in the atmosphere, co2, 33% greater than 18th century. Increased trapping of infrared - warms lower atmosphere, and changes weather: c02 poses more risk than methane in the atmosphere, both methane and c02 have increased their levels in the atmosphere, through human efforts. Observed changes: we have seen changes as a result for greenhouse gases in the atmosphere (a) global average surface temp; (b) global average sl from tide gauge and satellite data (c) north hemisphere spring snow cover. Glacier reduction: great majority of glaciers retreating at rates = or >> long established trends (nasa/us geol. Survey: air temperature is the most important factor in glacier retreat.
