Presentation on theme: "Bridging the Gap between Scientific and Public Understanding of the Climate Change Problem. The case for Immediate and Forceful Action Eric Grimsrud Retired."— Presentation transcript:
Bridging the Gap between Scientific and Public Understanding of the Climate Change Problem. The case for Immediate and Forceful Action Eric Grimsrud Retired Professor of Chemistry Montana State University Now living in Bigfork, MT, and Mesquite, NV contact: ericgrimsrud.com
Outline of this presentation: 1.The two factors that determine the Temperature of the Earth. 2.The Notion of Anthropogenic Global Warming (AGW). 3.Have we converted a lot of Geological Carbon to Biological Carbon? 4.Does the Biological Carbon go back to Geological Carbon? 5.Is atmospheric CO2 increasing? 6.So what? Lessons of the Ice Core Record. 7.Is the Earth’s temperature rising? 8.But other factors also affect climate. 9.What is the “Sensitivity” of CO2 - this is what the argument is all about. 10.What level of CO2 might be OK? The Ocean Bottom Core Record. 11.How can we possibly get back to 350 ppm ??? 12.Questions.
But not all of that incoming sunlight sticks – due to the albedo of the Earth. (1) The Earth is heated by the Electromagnetic Radiation coming from the Sun.
The albedo of the Earth is the fraction of incoming solar radiation that is reflected back out into space. The average albedo of the Earth is presently about 0.30. During the last glacial period, it was about 0.33. During the “Snowball Earth” period, It was about 0.9
But only a small portion of that outgoing infrared radiation is emitted from the surface of the Earth. – due to the Green House Effect. (2) The Earth cools itself by the emission of Electromagnetic Radiation of longer wavelength (called Infrared Radiation, IR)
=+73 F Only about 6 % of the IR emitted from the Earth’s surface makes it out.
Which molecules are greenhouse gases? All molecules having 3 or more atoms. Why? Because they have asymmetrical vibrational modes of motion that cause the location of their electrons to change as the molecule vibrates. If the frequency of that vibration happens to be the same as the frequency of the IR radiation, then that IR radiation will be absorbed by that molecule.
% ppm N 2 78 O 2 21 Ar 0.93 CO 2 0.039 392 excess lasts several millennia!! H 2 O 0 to 3 only days Ne 18 CH 4 1.9 10 years H 2 0.5 Concentrations and Lifetimes of the major GHG’s
% ppm ppb N2O N2O 250 100 years O 3 30 minutes CF 2 Cl 2 0.53 100 years CFCl 3 0.28 100 years
A Common Sense View of AGW geological forms of carbon biological forms of carbon coal, oil and gas and limestone CO2 in air, CO2 in oceans and C in plants, soil and animals Prior to the industrial revolution, the exchange between GC and BC was very slow in BOTH directions GC BC before 1850 slow
after 1850 geological forms of carbon biological forms of carbon coal, oil and gas and limestone CO2 in air, CO2 in oceans and C in plants, soil and animals BC will increase and the excess will not return to GC for a very long time. Plants might like the excess BC, but the atmosphere and oceans do not. GC BC FAST! still slow
“business as usual” models "Image created by Robert A. Rohde / Global Warming Art"
Figure 1. Fossil fuel and land-use CO2 emissions, and potential fossil fuel emissions. Historical fossil fuel emissions are from the Carbon Dioxide Information Analysis Center [CDIAC, S34] and British Petroleum [BP, S35]. Lower limits on oil and gas reserves are from IPCC [S36] and higher limits are from the United States Energy Information Administration [EIA, 80]. Lower limit for coal reserves is from the World Energy Council [WEC, S37] and upper limit from IPCC [S36]. Land use estimate is from integrated emissions of Houghton/2 (Fig. S14) supplemented to include pre-1850 and post-2000 emissions; uncertainty bar is subjective. References are given by Hansen et al. (Open Atmos. Sci. J. 2, 217-231, 2008). Fossil Fuels. To 2008
Note: only about 2% of the total CO2 flux to atmosphere today is due to fossil fuel use.
Direct atmospheric measurements (the Keeling Curve) "Image created by Robert A. Rohde / Global Warming Art" Note: was 280 ppm prior to Industrial Revolution, so NO, the excess CO2 does not quickly go back to GC About half of extra CO2 emitted from fossil fuels stays in the atmosphere.
The CO2 “overload” due to the combustion of fossil fuels has a very long lifetime, on the order of a few millennia. Therefore, every day we set a new higher level of atmospheric CO2 that will last essentially “forever” on a time scale of relevance to existing civilization. Note: In 2007, 450 ppm CO2 was considered a laudable goal. “Things” are now thought to be worse than they were is 2007 and 350 ppm is now considered to be the number we should shoot for by the end of this century.
Different ice cores – nearly identical results from ocean bottom core samples
From 2007 IPCC Report Increase over Industrial Age N2O - 30% CO2 - 40% CH4 - 250%
Note: the present level of Forcing by CO2 is expected to last “forever” and temperature always catches up within a few decades. From “Target Atmospheric CO2: Where should humanity aim?” by Hansen et al., 2008,. Yikes!!! way too much positive GHG forcing!
the Milankovitch cycles E - distance from sun T - magnitude of tilt P - direction of tilt the determining factor here is how warm a summer the Northern Hemisphere has. During the last two million years, climate changes have been initiated by: These small changes were then greatly amplified by the albedo and greenhouse gas feedbacks.
The definition of CO2’s temperature Sensitivity is: The temperature change caused by a doubling of CO2 concentration in the atmosphere. For example, the concentration of CO2 was 280 ppm prior to the industrial revolution. At the present rate of increase (2 ppm /year), the CO2 will reach 560 ppm in 2096. The temperature increase at that point will be equal to the Sensitivity of CO2.
From “Target Atmospheric CO2: Where should humanity aim?” by Hansen et al., 2008,. These ice core measurements of temperature and CO2 concentration indicate that the magnitude is CO2’s Sensitivity is 6.5 degrees C if both “fast” and “slow” feedbacks are included. Of this, 3.0 degrees is due to short-term “fast” feedbacks and 3.5 degrees is due to the “slower” long-term feedbacks (these include the “sheet ice” changes of Greenland and Antarctica).
Consider the following ancient temperature record (from ocean bottom core samples) CO2 = 450 ppm (boundary to “water world”) / --- 390 ppm today --- 290 ppm 160 years ago --- 180 ppm 15,000 years ago CO2 = 1,500 ppm end of dinosaur era recent Ice Age (from shells of foraminifara) Ice on Antarctica also on Greenland, also on the continents Sea level = 70 meters
Additional poorly understood possibilities: - Sheet ice break-up, Greenland and West Antarctic. - Disruption of the Oceanic “conveyer belt”. - Run-away CH4 or CO2 emissions from permafrost. - Methane Clathrate “burps”.
the oceanic “conveyer belt” plays an important role in the global distribution of heat.
We know how we got here. How do we get out? James Hansen’s opinion (Head of Nasa-Goddard Space Science Research Center) 1.Must reduce CO2 level to 350 ppm in this century. 2.Greatly improve efficiencies of energy use, of course. 3.Use existing reserves of gas and oil and don’t worry so much about emission rates – but stop looking for more. 4. Stop using coal (because there is too much of it) and do not develop tar sands, shale oil, and coal to liquid or gas technologies (unless it includes CO2 capture and sequestration). 5. Continue development of alternates: solar, wind, geothermal, etc. 6. Build 3 rd and develop 4 th Generation Nuclear Power Plants. 7.By improved land use, pull 50 ppm CO2 out of the atmosphere. 8.Resort to bioengineering, if necessary. 9.Change Cap and Trade to Carbon Tax and 100% Dividend. 10.Don’t expect sufficient leadership from your elected officials.