1. ATMOSPHERIC SULFATE AEROSOLS By: John Joseph, Justin Hicks, and Daniel Silberstein

2. Overview Scattering: the deflection of radiation by particles in the atmosphere Solar (shortwave) radiation: the radiation that makes its way into the Earth’s atmosphere in the form of UV and visible waves Longwave radiation: radiation emitted by the Earth in the form of Infrared waves Earth’s Radiation Budget: Net radiation = Net solar radiation + Net longwave radiation Aerosols: small particles suspended in the atmosphere that scatter or absorb radiation (depending on their size) Geoengineering: artificial modification of Earth’s climate Albedo: Reflectivity of a given surface https://mynasadata.larc.nasa.gov/oyw/scool- featured-lesson-classification-of-clouds /

3. Overview http://usra.ca/echoreflection.php

4. Overview Mount Pinatubo Eruption in 1991 led to the release of 10 Teragrams of SO 2 From 1991-1993, global temperatures were 1°F (0.5°C) cooler Geoengineering with the use of Sulphate aerosols models the effects of volcanic eruptions Particles would be added into Stratosphere instead Goal of injecting Sulphate aerosols would be to decrease the average global temperature by decreasing the amount of UV radiation that makes it to Earth’s surface http://pubs.usgs.gov/fs/1997/fs113-97/

5. Science! How do Sulfate Aerosols do what they do? SO 2 (g) + 2H20 (g) H 2 SO 4 Sulfuric acid vapor in the stratosphere increases albedo. Vapor coagulates in stratosphere. Bigger drops have lower albedo. H 2 SO 4 vapor stays in atmosphere for years. Ideally,1 kg of sulfate aerosol can offset approximately 100,000 kg of CO 2.

6. Delivery Balloon o High payload. Military/civilian aircraft o Reusable, with low payload. ARTILLERY o Cannon and railgun.

7. Benefits of Using Sulfate Aerosols Decreases temperature ○ Reduces sea ice melting ○ Reduces land ice sheet melting ○ Reduces sea level rising Increases plant productivity ○ Increase in diffuse radiation allows plants to photosynthesize more efficiently Increases terrestrial CO2 sink Beautiful Sunsets http://www.dailymail.co.uk/news/article- 2138678/Edvard-Munch-The-Scream-painting- fetches-119m-Sothebys-auction.html

8. Criticisms of Using Sulfate Aerosols Slows the recovery of the ozone layer o Shown to be correlated with ozone depletion Less solar power Requires continuous injection o Short lifespan depending on location in atmosphere Cost o Airplanes ~ $225 million - $4 billion per year o Artillery shells ~ $30 billion per year o Stratospheric balloons ~ $21 billion - $30 billion per year No governing agency exists today Can lead to an increase in acid rain Kravitz et al. 2009

9. Summary Injection of sulfate aerosols ultimately increases the albedo and amount of scattering o decreasing the net solar energy decreases average global temperatures Essentially, the human race has already experienced the effects of atmospheric sulfate aerosols due to volcanic activity Like most solutions, injection of aerosols would be costly o injection could be paired with other methods to combat climate change More Sulphate aerosols will have to be pumped into the atmosphere the longer we wait to take action http://www.kr avmagagilber t.com/?attach ment_id=530

10. Works Cited Epstein, E. 3 May, 2012. Iconic ‘Scream’ painting fetches a whopping $119 million at auction. Daily Mail Online. 7 November, 2015. Iconic ‘Scream’ painting fetches a whopping $119 million at auction Kravitz, B., A. Marquardt, A. Robock, G. Stenchikov. 2009. Benefits, risks, and costs of stratospheric geoengineering. Geophysical Research Letters. 36: 1-9. 10.1029/2009GL039209, 2009 Benefits, risks, and costs of stratospheric geoengineering Rasch, P., S. Tilmes, R. Turco, A. Robock, L. Oman, C. Chen, G. Stenchikov, and R. Garcia. 2008. An overview of geoengineering of climate using stratospheric sulphate aerosols (Links to an external site.). Philosophical Transactions of the Royal Society 366: 4007-4037. DOI: 10.1098/rsta.2008.0131An overview of geoengineering of climate using stratospheric sulphate aerosols (Links to an external site.) Newhall, Chris, J. W. Hendley II, P. H. Stauffer. 28 February 2005. “The Cataclysmic 1991 Eruption of Mount Pinatubo, Philippines.” USGS, 113-97. 08 November 2015.The Cataclysmic 1991 Eruption of Mount Pinatubo, Philippines Wigley, Tom. "A combined mitigation/geoengineering approach to climate stabilization." University Corporation for Atmospheric Research. UCAR, 14 Sept. 2006. Web. 7 Nov. 2015.. Sharpwriter. "Bill Clinton the Lady Killer." DeviantArt. DeviantArt, 2013. Web. 6 Nov. 2015. http://sharpwriter.deviantart.com/art/Bill-Clinton-the-Lady-Killer-357619589>.