5 Research Topics Essential Questions (2): Climate Change

II. Climate Change

Pro/Con and Essential Questions




1. Is ethanol the best way to reduce U.S. dependency on foreign oil?

Expanding the use of ethanol--an environmentally clean fuel--will reduce our dependence on foreign oil. The United States relies on imported oil to meet its energy needs. The majority of its imports come from Canada, the Middle East and Venezuela. Many hope that by reducing its dependence on foreign oil, the U.S. can prevent major supply disruptions like the 1973 oil crisis. They also believe that energy independence will reduce prices in the United States, because prices will no longer be affected by political unrest in oil-producing nations. Options to reduce U.S. dependency on foreign oil include expanding the use of alternative energy sources such as ethanol and drilling for oil in Alaska or the Gulf of Mexico. Because ethanol burns cleaner than gasoline, it reduces greenhouse gas emissions by 34% to 59%. Because ethanol costs less than gasoline, it saves motorists more than $1,200 per year. When Congress crafted the RFS, it built in a great deal of administrative and market flexibility, allowing refiners and gasoline marketers to adjust to changing market dynamics that reduce the supply of biofuels. Last week, the U.S. Environmental Protection Agency (EPA) demonstrated the RFS' flexibility once again by reducing the requirement for cellulosic (non-grain) ethanol.


2. Are human activities causing global warming?

Human activities, such as greenhouse gas emissions, are causing global warming. Many believe greenhouse gas emissions, including carbon dioxide released by the burning of fossil fuels, contribute to global warming, while others believe global warming is the result of a cyclical change in weather patterns and is not cause for alarm. Factories burn fossil fuel which emit greenhouse gases like carbon dioxide which cause a rise in global temperatures which is the main cause of Global Warming. The rate of rise  of sea level was almost twice as fast over the past 20 years than earlier in the 20th century.Warming is continuing, despite the fact that in the last decade there were two cooling La Ninas in the Pacific Ocean and a prolonged solar minimum. These and other indicators of change all signal that human activities, such as the release of greenhouse gases, are changing our climate — a conclusion that 97 percent of climate scientists agree with in a recent peer-reviewed study.




3. Is global warming causing more natural disasters?


There is a link between global warming and natural disasters.Human influences are having an impact on some extreme weather and climate events, according to the report “Explaining Extreme Events of 2012 from a Climate Perspective” released today by the Bulletin of the American Meteorological Society. Overall, 18 different research teams from around the world contributed to the peer-reviewed report that examined the causes of 12 extreme events that occurred on five continents and in the Arctic during 2012. Scientists from NOAA served as three of the four lead editors on the report. The report shows that the effects of natural weather and climate fluctuations played a key role in the intensity and evolution of the 2012 extreme events. However, in some events, the analyses revealed compelling evidence that human-caused climate change, through the emission of heat-trapping gases, also contributed to the extreme event. In addition to investigating the causes of these extreme events, the multiple analyses of four of the events — the warm temperatures in the United States, the record-low levels of Arctic sea ice, and the heavy rain in both northern Europe and eastern Australia — allowed the scientists to compare and contrast the strengths and weaknesses of their various methods of analysis. Despite their different strategies, there was considerable agreement between the assessments of the same events.


4. Is there a link between ozone layer depletion and climate change?


Ozone layer depletion contributes to climate change. The global treaty that headed off destruction of earth's protective ozone layer has also prevented major disruption of global rainfall patterns, according to a new study in the Journal of Climate. The 1987 Montreal Protocol phased out the use of chloroflourocarbons, or CFCs, a class of chemicals that destroy ozone in the stratosphere, allowing more ultraviolet radiation to reach earth's surface. Though the treaty aimed to reverse ozone losses, the new research shows that it also protected the hydroclimate. The study says the treaty prevented ozone loss from disrupting atmospheric circulation, and kept CFCs, which are greenhouse gases, from warming the atmosphere and also disrupting atmospheric circulation. Had these effects taken hold, they would have combined to shift rainfall patterns in ways beyond those that may already be happening due to rising carbon dioxide in the air.
Today, rising carbon dioxide levels are already disturbing earth's hydrological cycle, making dry areas drier and wet areas wetter. But in computer models simulating a world of continued CFC use, the researchers found that the hydrological changes in the decade ahead, 2020-2029, would have been twice as severe as they are now expected to be. The ozone layer protects life on earth by absorbing harmful ultraviolet radiation. As the layer thins, the upper atmosphere grows colder, causing winds in the stratosphere and in the troposphere below to shift, displacing jet streams and storm tracks. The researchers' model shows that if ozone destruction had continued unabated, and increasing CFCs further heated the planet, the jet stream in the mid-latitudes would have shifted toward the poles, expanding the subtropical dry zones and shifting the mid-latitude rain belts pole-ward. The warming due to added CFCs in the air would have also intensified cycles of evaporation and precipitation, causing the wet climates of the deep tropics and mid to high latitudes to get wetter, and the subtropical dry climates to get drier.