Sbsp affirmative- arl lab- ndi 2011
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- AT: Ice Age- Probability
- AT: SO2 Screw
- Warming outweighs dimming
AT: Ice Age- TimeframeLet’s be serious – the ice age cycle comes back in 10,000 yearsChameides, ‘8 - Dean/Environmental Prof at Nicholas School at Duke University [Bill, 8/27/2008, “Did Climate Scientists Flip Flop?” Duke Environment at the Nicholas School, http://www.nicholas.duke.edu/thegreengrok/cooling, DS] The Earth’s climate for the past 2 million years has been characterized by ice ages lasting 100,000 years or so, punctuated by warm periods (or “interglacials”) lasting tens of thousands of years. We have a pretty good understanding of the causes of these climate swings: changes in the Earth’s orbit around the sun amplified by natural feedbacks involving greenhouse gases. The Earth entered the present interglacial about 10,000 years ago. All things being equal (i.e., in the absence of a large human-produced source of the heat-trapping gas carbon dioxide [CO2]), it is almost certain that the Earth will swing back into another ice age. But this will not occur for tens of thousands of years. As early as the 19th century, scientists recognized that greenhouse gases warm the planet, and increases in atmospheric CO2 could lead to global warming on time scales of decades to centuries — much shorter than the fluctuations related to ice ages and interglacials. Around the same time, global temperatures began to rise and scientists became increasingly concerned that people were interfering with the climate. AT: Ice Age- ProbabilityWe’re on the brink – best models prove high probability without fast actionScienceDaily, ‘5 [ScienceDaily, 12/7/2005, “Global Warming Could Halt Ocean Circulation, With Harmful Results,” http://www.sciencedaily.com/releases/2005/12/051207180807.htm#, DS] Absent any climate policy, scientists have found a 70 percent chance of shutting down the thermohaline circulation in the North Atlantic Ocean over the next 200 years, with a 45 percent probability of this occurring in this century. The likelihood decreases with mitigation, but even the most rigorous immediate climate policy would still leave a 25 percent chance of a thermohaline collapse. "This is a dangerous, human-induced climate change," said Michael Schlesinger, a professor of atmospheric sciences at the University of Illinois at Urbana-Champaign. "The shutdown of the thermohaline circulation has been characterized as a high-consequence, low-probability event. Our analysis, including the uncertainties in the problem, indicates it is a high-consequence, high-probability event." Schlesinger will present a talk "Assessing the Risk of a Collapse of the Atlantic Thermohaline Circulation" on Dec. 8 at the United Nations Climate Control Conference in Montreal. He will discuss recent work he and his colleagues performed on simulating and understanding the thermohaline circulation in the North Atlantic Ocean. The thermohaline circulation is driven by differences in seawater density, caused by temperature and salinity. Like a great conveyor belt, the circulation pattern moves warm surface water from the southern hemisphere toward the North Pole. Between Greenland and Norway, the water cools, sinks into the deep ocean, and begins flowing back to the south. "This movement carries a tremendous amount of heat northward, and plays a vital role in maintaining the current climate," Schlesinger said. "If the thermohaline circulation shut down, the southern hemisphere would become warmer and the northern hemisphere would become colder. The heavily populated regions of eastern North America and western Europe would experience a significant shift in climate." Higher temperatures caused by global warming could add fresh water to the northern North Atlantic by increasing the precipitation and by melting nearby sea ice, mountain glaciers and the Greenland ice sheet. This influx of fresh water could reduce the surface salinity and density, leading to a shutdown of the thermohaline circulation. "We already have evidence dating back to 1965 that shows a drop in salinity around the North Atlantic," Schlesinger said. "The change is small, compared to what our model needs to shut down the thermohaline, but we could be standing at the brink of an abrupt and irreversible climate change." To analyze the problem, Schlesinger and his colleagues first used an uncoupled ocean general circulation model and a coupled atmosphere-ocean general circulation model to simulate the present-day thermohaline circulation and explore how it would behave in response to the addition of fresh water. They then used an extended, but simplified, model to represent the wide range of behavior of the thermohaline circulation. By combining the simple model with an economic model, they could estimate the likelihood of a shutdown between now and 2205, both with and without the policy intervention of a carbon tax on fossil fuels. The carbon tax started out at $10 per ton of carbon (about five cents per gallon of gasoline) and gradually increased. "We found that there is a 70 percent likelihood of a thermohaline collapse, absent any climate policy," Schlesinger said. "Although this likelihood can be reduced by the policy intervention, it still exceeds 25 percent even with maximal policy intervention." Because the risk of a thermohaline collapse is unacceptably large, Schlesinger said, "measures over and above the policy intervention of a carbon tax -- such as carbon capture and sequestration -- should be given serious consideration." AT: SO2 ScrewDimming low nowWesterly Sun 10 [Earth Talk, 12-2010, “Global dimming a result of pollution,” http://www.thewesterlysun.com/news/article_f919852a-039e-11e0-8702-001cc4c03286.html] Columbia University climatologist Beate Liepert notes a reduction by some 4 percent of the amount of solar radiation reaching the Earth's surface between 1961 and 1990, a time when particulate emissions began to skyrocket around the world. But a 2007 study by the National Aeronautics and Space Administration found an overall reversal of global dimming since 1990, probably due to stricter pollution standards adopted by the U.S. and Europe around that time. Warming outweighs dimmingReynolds 10 – PhD in Atmospheric Sciences [Michael, Around the Americas, “Report from the On-board Scientist: Aerosols, Volcanoes and Global Dimming,” http://www.aroundtheamericas.org/log/report-from-the-on-board-scientist-aerosols-volcanoes-and-global-dimming/] On the other hand, aerosols can add heat to the atmosphere which partially offsets the cooling effect. As the Earth heats up from the sun, it radiates heat back to space. Aerosols absorb some of the heat radiation and reduce the amount of heat radiation escaping out to space. This is the same heat-blocking effect attributed to greenhouse gasses, and in this way aerosols can have a heating effect on global climate. Nevertheless, the net effect of aerosols is to reduce the rate of global warming from greenhouse gasses. Does this mean we should all go build fires and drive our cars? No, because the offset that aerosols make on all of all these activities is smaller than the impact those activities make on global warming. Models and data now show that aerosols reduce the increase in global temperature by a factor of approximately 50% (there is uncertainty in the actual amount). So, they slow down the process but do not stop it. And they create pollution and effect health at the same time. Directory: files files -> Answer True False 2 points Question 2 files -> Integer programming and game theory files -> 4 Integer Programming files -> Bpa vehicle Window Repair Scenario #1 task: Procure vehicle window relacement. 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