Intro to the Greenhouse Effect Climate and Climate

Intro. to the Greenhouse Effect Climate and Climate Change

Intro. to Greenhouse Effect: Outline • Atmospheric Gases: “Greenhouse” or Not? – How gases can store heat energy • Step-by-Step of the Greenhouse Effect – How energy enters Earth’s systems – How energy is absorbed and retained • Impact on Earth’s Climate – Prehistoric data – Modern data

Atmospheric Gases: Non-“Greenhouse” These gases are simple, either one atom or two. They store energy through translating or (sometimes) rotating.

Atmospheric Gases: “Greenhouse” These gases are complex, at least three atoms bonded together. They store energy through translating, rotating, or complex vibrations. For extreme physics details, CLICK HERE

Greenhouse Effect Steps: Overview

Greenhouse Effect Steps: 1. Sun’s Energy Enters • Most of the atmosphere is transparent to “visible” light – Why you can see through it most of the time • Most incoming solar radiation is “visible” kind (see graph later) By Handyhuy (Own work) [CC-BY-SA-3. 0 (http: //creativecommons. org/licenses/by-sa/3. 0)], via Wikimedia Commons

Greenhouse Effect Steps: 2. Ground Absorbs Energy • You can’t see through the Earth’s surface – Ground and other surface features absorb visible light and heat up • E. g. , dark objects absorb more light and heat up more easily http: //blogs. kxan. com/2011/06/17/will-it-be-hottest-summer-ever/

Greenhouse Effect Steps: 3. Ground Radiates IR Energy • Infrared radiation (IR) is released from warm bodies – E. g. , the hot ground releases it in all directions • “Night vision” goggles pick up IR, by the way By Brocken Inaglory (Own work) [Public domain], via Wikimedia Commons

Greenhouse Effect Steps: 4. GHGs Absorb IR Energy • Greenhouse gases (GHGs) have the complex motions that match the IR energy – IR traveling from the surface hits gases – GHGs begin vibrating (i. e. , heating up, storing the energy) • Heated GHGs also release IR! By Nick 84 [CC-BY-SA-3. 0 (http: //creativecommons. org/licenses/by-sa/3. 0)], via Wikimedia Commons

Greenhouse Effect Steps: Revisited

Impact on Earth’s Climate: Prehistoric Data By Vostok-ice-core-petit. png: NOAA derivative work: Autopilot (Vostok-ice-core-petit. png) [CC-BY -SA-3. 0 (http: //creativecommons. org/licenses/by-sa/3. 0/) or GFDL (http: //www. gnu. org/copyleft/fdl. html)], via Wikimedia Commons

Impact on Earth’s Climate: Modern Data (Slide 1) By US Govt (NOAA (http: //www. esrl. noaa. gov/gmd/aggi/)) [Public domain], via Wikimedia Commons

Impact on Earth’s Climate: Modern Data (Slide 2) • “Global mean land-ocean temperature change from 1880– 2013, relative to the 1951– 1980 mean. The black line is the annual mean and the red line is the 5 -year running mean. The green bars show uncertainty estimates. ” Wikipedia contributors. "Global warming. " Wikipedia, The Free Encyclopedia, 12 Oct. 2014. Web. 14 Oct. 2014. By NASA Goddard Institute for Space Studies (http: //data. giss. nasa. gov/gistemp/graphs/) [Public domain], via Wikimedia Commons

Check yourself • Is heat trapped on the way in or the way out? • Given what you know about Mars and/or Venus, how do you think the greenhouse effect impacts their climates? • How “effective” a greenhouse gas do you think the following molecule is? By Walkerma (Own work) [CC 0], via Wikimedia Commons