What are the trends in greenhouse gas emissions and concentrations and their impacts on human health and the environment?
Importance of Greenhouse GasesGreenhouse gases, such as carbon dioxide, methane, nitrous oxide, and certain synthetic chemicals, trap some of the Earth's outgoing energy, thus retaining heat in the atmosphere. This heat trapping causes changes in the radiative balance of the Earth—the balance between energy received from the sun and emitted from Earth—that alter climate and weather patterns at global and regional scales. Show
Multiple lines of evidence confirm that human activities are the primary cause of the global warming of the past 50 years.1 Natural factors, such as variations in the sun's output, volcanic activity, the Earth's orbit, the carbon cycle, and others, also affect Earth's radiative balance. However, beginning in the late 1700s, the net global effect of human activities has been a continual increase in greenhouse gas concentrations. This change in concentrations causes warming and is affecting various aspects of climate, including surface air and ocean temperatures, precipitation, and sea levels. Human health, agriculture, water resources, forests, wildlife, and coastal areas are all vulnerable to climate change. Many greenhouse gases are extremely long-lived in the atmosphere, with some remaining airborne for tens to hundreds of years after being released. These long-lived greenhouse gases become globally mixed in the atmosphere and their concentrations reflect past and recent contributions from emissions sources worldwide. Others, like tropospheric ozone, have a relatively short lifetime in the atmosphere. Other Factors Affecting Climate ChangeIn addition to greenhouse gases, other related factors, including other radiatively important substances and albedo, can alter the Earth's climate.
Although this ROE question does not address radiatively important substances or albedo, both factors are important to understanding the planet's energy balance and the ways human activities may affect that balance.2 Greenhouse Gases and Their SourcesSome greenhouse gases are emitted exclusively from human activities (e.g., synthetic halocarbons). Others occur naturally but are found at elevated levels due to human inputs (e.g., carbon dioxide). Anthropogenic sources result from energy-related activities (e.g., combustion of fossil fuels in the electric utility and transportation sectors), agriculture, land-use change, waste management and treatment activities, and various industrial processes. Major greenhouse gases include carbon dioxide, methane, nitrous oxide, and various synthetic chemicals.
Each greenhouse gas has a different ability to absorb heat in the atmosphere, due to differences in the amount and type of energy that it absorbs, and a different “lifetime,” or time that it remains in the atmosphere. For example, it would take thousands of molecules of carbon dioxide to equal the warming effect of a single molecule of sulfur hexafluoride—the most potent greenhouse gas—in terms of ability to absorb heat, as evaluated by the Intergovernmental Panel on Climate Change (IPCC).3 To facilitate comparisons between gases that have substantially different properties, the IPCC has developed a set of metrics called “global warming potentials.”
Impacts of Climate ChangeThe changing climate affects society and ecosystems in a variety of ways. For instance:
These and other aspects of climate change are disrupting people's lives and damaging some sectors of the U.S. economy.4 This has led many state and local governments to prepare for these impacts through “adaptation” (i.e., planning for the changes that are expected to occur). ROE IndicatorsThe ROE presents six indicators showing trends in greenhouse gas emissions and their associated environmental impacts: Greenhouse Gas Emissions, Greenhouse Gas Concentrations, Energy Use, Temperature and Precipitation, Sea Level, and Sea Surface Temperature.
There are a few limitations associated with the ROE greenhouse gas indicators.
References[1] Melillo, J.M., T.C. Richmond, and G.W. Yohe (eds.). 2014. Climate change impacts in the United States: The third National Climate Assessment. U.S. Global Change Research Program. [2] Detailed information on these related factors can be found in various scientific publications, such as those prepared by the Intergovernmental Panel on Climate Change, a panel formed by the World Meteorological Organization to compile and synthesize the growing body of scientific literature on climate change. [3] Intergovernmental Panel on Climate Change. 2013. Climate change 2013: The physical science basis. Working Group I contribution to the IPCC Fifth Assessment Report. Cambridge, United Kingdom: Cambridge University Press. [4] Melillo, J.M., T.C. Richmond, and G.W. Yohe (eds.). 2014. Climate change impacts in the United States: The third National Climate Assessment. U.S. Global Change Research Program. [5] U.S. Environmental Protection Agency. 2016. Inventory of U.S. greenhouse gas emissions and sinks: 1990-2014. EPA 430-R-16-002. Which of the following is one of the main things to consider when evaluating a business opportunity quizlet?The five things to consider when evaluating a business opportunity are customer demand, competition, timing, money, personality and skills.
What are demographics in business quizlet?Demographics refers to the descriptive characterisitcs, such as age, gender, race, income, etc.
Which of the following sections of a business plan comes first but should be written last quizlet?Even though the executive summary appears at the beginning of the business plan, it should be written last. If you write the executive summary first, you run the risk of trying to write a plan that fits the executive summary rather than thinking through each piece of the plan independently.
How does limiting a company's scope benefit the company?It allows the company to hire more employees. It makes it easier to produce a high quality product.
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