Group IV Project: Geoengineering Jens Yukari Hoyong Seika

Geoengineering - Geoengineering means different things to different people - Reduce the amount of climate change produced by the greenhouse gasses that increases. (CO2, methane and nitrogen oxide) - Remove the greenhouse gasses have been released into the atmosphere - Proposals: - Carbon Dioxide Removal (CDR) - Solar Radiation Management (SRM) - Arctic Geoengineering

Geoenginering Involves CO2 removal (CDR) Cleaning atmosphere by removing CO2 from it. planting trees (sucks CO2) developing technologies to capture and store CO2 emissions by power plants ocean iron fertilization- adding iron to ocean water to increase phytoplankton plants afforestation biochar Advantages low risk more direct approach in trying to solve global warming Disadvantage Not fast enough if the goal is to reduce global temperature

Background of Geoengineering -Why is it neccesary? -Global Warming -Sudden climate change is irreversible -Arctic ice is shrinking -NASA, Royal Society, and various groups are taking part in research -Potential is being evaluated -Identifying and reducing possible risks

Why Consider as a Climate Change Solution? Focused on either CO2 removal or SRM. These both aim at reducing global warming which is a term used for the increase in the average temperature of the earth and the oceans. Global warming can result in rise of sea levels due to melting polar ice an also to more severe storms and weather occurences. This is why geoengineering is considered a climate change solution.

Risks and Criticisms - Less CO 2 removal -Ocean acidification -Negative environmental side effects -Doubt over effectiveness -Clouds, solar radiation can be affected -Lessen the public will to address climate change -“Something’s already been done” -Ethical issues - Do we have the rights to control climate?

Solar Radiation Management -Solar Radiation Management (SRM) is one of the proposes to reduce global warming by: -Purposely changing the Earth’s albedo (reflectivity) -Attempts to reflect sunlight that is hitting the Earth and thus reduce global warming -Purposely preventing sunlight from reaching the Earth -Intercept sunlight from reaching the Earth and thus reduce global warming

Background -Hoyle (1957) -Kahle and Deirmendjian (1973) -Direct manipulation of “global dimming” -Warming effect by global warming can be cancelled out -Though the cancellation is not perfect -Reaching a 0.5% albedo increase -> halving the effect of CO 2 doubling

Advantages and Disadvantages to SRM Advantages -Relatively inexpensive -Speed (easy to set up and start) -A “quick fix” to climate change Disadvantages -May cause enviornmental hazards -Monsoons, droughts -A risk of abrupt cessation exists -Results in as sudden rise in global temperatures -> severe consequences -Risk to humans and plants -Photosynthesis requires direct sunlight -Chemicals breathed in, lack of direct sunlight for humans (vitamin D, etc.)

SRM Projects -Atmospheric Projects -Stratospheric sulfur aerosols -Reflective aerosols or dust -Cloud whitening/cloud reflectivity -Cloud seeding -Ocean sulfur cycle enhancement -Reflective balloons -Low stratospheric soot -Terrestrial Albedo Modification -Cool Roof -Reflective sheeting -Ocean changes -Farming, Foresting, and Land Management -Forestry Management -Grassland Management -High-albedo crop varieties -Space Projects -Space mirrors -Moon dust -Dispersive solutions

Stratospheric Sulfur Aerosols -Tom Wigley’s proposal to inject sulfate particles (aerosols) into the stratosphere -Creates a white haze in the sky, which will reflect sunlight and less of the sun’s radation will hit the earth

Forest and Grassland Management -Possible Changes to Grassland -Use plants with high albedo (genetically modified) -Reforestation & Deforestation -Reforestation in the tropics has a cooling effect on the Earth -Deforestation in higher locations such as mountaintops increases the reflectivity of sunlight

Space-Based Projects -A future project due to technological restrictions at the present -Space Mirrors -Sending mirrors to orbit the Earth and reflect sunlight -Moon Dust -Mine moon dust and form a cloud surronding the earth -Dispersive Solutions

Biology Lab: “Cool Roof” -The “Cool Roof” strategy proposes to reduce the amount of sunlight by reducing the amount of heat transfer -Reflecting light from the sun -Calls for many surfaces of the Earth, especially roads, pavements, and roofs to be pale-colored -Pale-colored roofs absorb less and reflect more than dark-colored

Biology Lab: “Cool Roof” Objective: To investigate the absorption and reflection rate for plastic PET bottles painted black and white to model the “cool roof” technique used for Solar Radiation Management, one of the proposed strategies of geoengineering

Biology Lab: “Cool Roof” Procedure 1. Take two plastic pet bottles 2. Paint one of the containers black and the other white 3. Put the two containers outside in the SHADE, and leave for 10 minutes 4. Put a thermometer inside each of the containers, record their temperatures (this is the initial temperature) 5. Move them into the sunlight (or under bright light but preferably sunlight) 6. Record their temperature at 1 minute intervals for 5 minutes 7. Compare the temperature for the two containers Materials -2 identical plastic pet bottles -2 identical thermometers -Black spray paint -White spray paint -Stopwatch

Biology Lab: “Cool Roof” Results: -The results showed that there was a difference of at least 1-2 degrees between the black and white pet bottles -Though that may seem like a little, 1-2 degrees is a big difference if it was the temperature of the Earth