Alan Robock Department of Environmental Sciences Rutgers University, New Brunswick, New Jersey USA Climate Dynamics 11:670:461 Lecture 2, 9/9/13

Alan Robock Department of Environmental Sciences Nitrogen (N 2 ), oxygen (O 2 ), and argon (Ar) make up for 99% of the atmosphere, but are not greenhouse gases. Water vapor (H 2 O), carbon dioxide (CO 2 ), methane (CH 4 ), ozone (O 3 ), and nitrous oxide (N 2 O) are greenhouse gases. A greenhouse gas absorbs infrared radiation, which creates molecular vibration and bending. Collisions transfer energy to heat the surrounding gas. But, what is a “greenhouse gas” anyway? Water vapor (H 2 O) vibration modes

Alan Robock Department of Environmental Sciences Produced by Gary Strand, NCAR CCSM Climate “Forecasts” (°C)

Alan Robock Department of Environmental Sciences IPCC AR4, Chapter 1 Fig. 1.1

Alan Robock Department of Environmental Sciences Fig. 1.2 Bretherton Diagram

Alan Robock Department of Environmental Sciences Fig. 1.2 Bretherton Diagram

Alan Robock Department of Environmental Sciences

Alan Robock Department of Environmental Sciences

Alan Robock Department of Environmental Sciences

Alan Robock Department of Environmental Sciences Recovery from volcanic eruptions dominates Tropospheric aerosols mask warming (global dimming) Greenhouse gases dominate

Alan Robock Department of Environmental Sciences Desire for improved well-being Consumption of goods and services Impacts on humans and ecosystems Climate change CO 2 in the atmosphere Consumption of energy CO 2 emissions CONSERVATION EFFICIENCY LOW-CARBON ENERGY SUFFERING S O L A R R A D I A T I O N M A N A G E M E N T CARBON DIOXIDE REMOVAL ADAPTATION After Ken Caldeira

Alan Robock Department of Environmental Sciences Annual average surface air pressure. Interval 50 mb. Fig. 2.1

Alan Robock Department of Environmental Sciences Fig. 2.1 Annual average surface air pressure. Interval 50 mb.

Alan Robock Department of Environmental Sciences Fig. 2.2

Alan Robock Department of Environmental Sciences Fig. 2.3 Annual mean 900 mb geopotential height (m) Annual mean 200 mb geopotential height (m)

Alan Robock Department of Environmental Sciences Fig. 2.3 Annual mean 900 mb geopotential height (m) Annual mean 200 mb geopotential height (m)

Alan Robock Department of Environmental Sciences Seasonal 900 mb geopotential height (m) Fig. 2.4