You need to review both article and lecture notes to answer the following questions. Briefly describe the greenhouse effect. What human activities are impacting natural cycle of greenhouse effect? Any examples? As described in “A Safe Operating Space for Humanity,” describe planetary boundaries generally and explain why they are important.What are the branches of scientific enquiry that the authors of “A Safe Operating Space for Humanity” have used in their study of planetary boundaries? Based on class notes describe environmental and health impacts of coal combustion and research their relation to the climate change.What is the delicate balance described in the article?Explain why the humanity has the freedom to pursue long-term social and economic development as long as the thresholds are not crossed? Essay According to scientists oceans are warming much faster than previously calculated values due to technologies available today such as wireless temperature sensors that can measure ocean temperatures in very deep waters and send the data to computer systems precisely. This may cause frequent hurricanes and storms that may devastate costal areas. Similarly harsh temperature changes in Midwestern states may induce more frequent draught and flood cases as well as tornados and storms than ever before. If global warming and climate change become serious public concerns in your hometown or in general in Iowa, what might be your response to resolve and help reduce the environmental impacts of it? What are the challenges? Provide examples and offer methods to resolve the issue(s).
The Global Environment: An Emerging World View (cont.)
Read Article 5, A safe operating space for humanity by Johan Rockstrom et al. on pages 36-41 in your textbook.
This lesson will illustrate understanding of how locally-based activities influence global phenomena as climate change. You will also observe that in a time of disappointing progress is occurring in global initiatives to curb greenhouse gas emissions, one of the most promising paths might be a localized action.
The authors identified planetary boundaries that must not be crossed in order to avoid significant environmental degradation.
Of the 10 factors considered, 3 of them–biodiversity loss, climate change,and agricultural pollution–have already crossed the threshold for a sustainable planet.
Evidence so far suggests that, as long as the thresholds are not crossed, humanity has the freedom to pursue long-term social and economic development.
- Planetary Boundaries
- Climate Change
- Rate of Biodiversity Loss
- Nitrogen and Phosphorus Cycles
- Delicate Balance
Planetary Boundaries — boundaries that define the safe operating space for humanity with respect to the Earth system and are associated with the planet’s biophysical subsystems or processes.
Holocene — the unusually stable environment of the planet for the past 10,000 years, which has seen human civilizations arise, develop, and thrive.
Anthropecene — an era that has arisen since the Industrial Revolution, in which human actions become the main driver of global environmental change.
EPA — Environmental Protection Agency (www.epa.gov) for more information.
Greenhouse Gas (GHG)– an atmospheric gas such as carbon dioxide, water vapor, or methane that easily absorbs infrared radiation & gives off heat, some of it directed toward space & the rest toward Earth.
Carbon Cycle — the cycle of CO2 in the Earth‘s ecosystem; photosynthetic organisms transform the gas into organic nutrients, which are then restored to a gaseous state by respiration & decay.
Fact 1: Currently, atmospheric CO2 concentration is 31% higher than in 1750, a level that has not been exceeded during the last 420,000 years.
Fact 2: The primary cause is human activity, particularly fossil fuel use & deforestation leading to further increases in CO2.
As we have seen a similar trend in the previous lesson, the following graph illustrates the CO2 concentration (dashes) and the global surface Ts (solid line)
Fact 3: Burning fossil fuels in power plats and automobiles ejects poisonous particles & gases that alter the chemical structure of the Atmosphere.
Fact 4: Worldwide CO2 emissions from burning fossil fuels (coal, oil, and natural gas) reached a record 30.6 Billion metric tons in 2010 that economists and scientist call this as “a wake-up call”. (Source: International Energy Agency). This was a 5% increase from 2009!
Introduction to the Greenhouse Effect
Before reaching the earth’s surface, solar radiation passes through clouds and atmosphere, which reflect, scatter, absorb, and transmit various amounts of energy. The earth’s surface reflects some of the incoming solar radiation and absorbs the remainder. As the surface absorbs the energy, it heats and radiates the energy back into space.
When the rates of absorption & radiation are equal (radioactive balance) the earth’s temperature is stable. However, some gases “CO2 , CH4 , Nitrous Oxide (N2O), water vapor, and, Hydrofluorocarbons (HFCs)” in the atmosphere absorb some of the energy radiated from the surface. They heat, trap, and re-radiate energy back to the surface.
In this way, the atmosphere maintains a higher surface T than the earth would have without an atmosphere. This process is called the greenhouse effect as shown in the following picture.
There is a natural greenhouse effect which keeps the Earth warm (ave temperature about 60OF) to be habitable.
Greenhouse gases like carbon, dioxide, methane, nitrous oxide, & water vapor trap heat and warm the earth’s surface!
How the Earth’s climate response to enhanced greenhouse gases also depend on complex interactions between the atmosphere, oceans, land, ice, & biosphere!
Emissions of CO2 accounted largest share of US greenhouse emissions-about 85% of the total!
Power utilities, transportation, and industries constitute major sources of fossil fuel CO2 emissions!
Greenhouse gas emissions are disturbing the way the climate maintains the balance between incoming and outgoing energy.
CO2 emissions in the World as of 1996 is shown in the following graph.
The UN’s ‘Intergovernmental Panel on Climate Change’ (IPCC) studied all the available evidence, and concluded that climate change is happening, that it is caused by the burning of fossil fuels, and that the world is likely to get a lot hotter than previously thought.
The IPCC predicts that, unless action is taken to reduce emissions of particularly CO2 and other climate-changing pollutants; the world will experience:
More heat waves and floods.
Glaciers and polar ice are set to continue melting.
Sea levels could rise by up to six meters.
Many plant & animal species will become extinct.
Outbreaks of diseases will become more common.
Millions of people will be forced to move.
The image below showes an 1870 postcard view of the Rhone glacier in Gletsch, Switzerland contrasted with the shrinking 21st-century version. In an 2006, Max Maisch, an expert on the topic at the University of Zurich, told The New York Times that “This year was a terrible year for the glaciers. July was very hot, though August was cool; but September was the warmest in 140 years. Many glaciers are collapsing on the edges.”
This 2006 article from The New York Times, Global Warming Poses Threat to Ski Resorts in the Alps, also describes the problems climate change is causing in Europe.
Glaciers in Europe are not the only one experiencing problems. Glaciers in the Himalays are retreating at a rate of 33 to 49 feet each year. Some of the effects of this are:
Billions of people in China and the Indian subcontinent rely on South Asia’s Himalayan glaciers – the world’s largest store of fresh water outside the polar ice caps. The massive ice floes feed seven of the world’s greatest Asian rivers in one of the world’s most densely populated regions
In the Himalayas, the Gangotri Glacier, one of India’s largest, is entitled to an even more dubious distinction. Recent studies reveal that the Gangotri, which forms a mass of ice about 18 miles long, is retreating at a rate of more than 100 feet a year.
In Greenland, a peninsula long thought to be part of the mainland has been discovered to be an island once a glacier retreated. Watch this video, for a detailed story on this “new” island. The island was discovered by explorer Dennis Schmitt in September, 2005. As the Greenland Ice sheet melts, new islands are expected to continue to appear.
There is also an interactive map, Sea Ice in Retreat, that shows the changes in sea ice from 2003 to 2007.
The National Center for Atmospheric Research (NCAR) and University Corporation for Atmospheric Research (UCAR) at University of Colorado at Boulder conducted a study that predicts the artic may be devoid of sea ice during the late summer by 2040. They created an animation based on the simulations. You can watch it here, http://www.youtube.com/watch?v=JkfMQdrzSok.
Coal Combustion and Impacts to the Environment and Human Health
Today 52% of the capacity for generating electricity in the US is fueled by coal. First, coal combustion produces CO2 and other greenhouse gases that are suspected to cause climatic warming, and it is a source of sulfur oxides (SO2) and nitrogen oxides, which are harmful to human health & may be largely responsible for acid rain.
Second, although not as well known, releases from coal combustion contain naturally occurring radioactive materials “uranium & thorium.” Coal ash is composed primarily of oxides of silicon, aluminum, iron, calcium, magnesium, titanium, sodium, potassium, arsenic, mercury, and sulfur plus small quantities of “uranium & thorium”. US & world release of uranium & thorium from coal combustion risen since early 20th century. Americans living near coal-fired power plants might be exposed to higher radiation doses than those living near nuclear power plants that meet government regulations!
Large quantities of uranium, thorium & other radioactive species in coal ash are not being treated as radioactive waste. These products emit low-level radiation, but because of regulatory differences, coal-fired power plants are allowed to release quantities of radioactive material that would provoke enormous public attention if such amounts were released from nuclear facilities. According to National Council on Radiation Protection & Measurement, ave radioactivity per ton of coal is 4.27 microcuries/ton. Population exposure from operation of 1000MW nuclear and coal-fired power plants amount to 490-rem/year for coal plants & 4.8 person-rem/year for nuclear plants.
The Result: Population effective dose equivalent from Coal plants is 100 times that from nuclear plants. Compare the two graphs below.
Today (2004), many new coal fired power plants are being constructed due to the C02 regulations “eased” by Bush Administration. The interconnected histories of Technology, Energy, Population, and economic growth have impacted on the environment. Science applied to chemical industry in 19th century, generated some 80,000 new compounds and their mixture with eco-systems causing destructive results in fisheries, genes, birds, etc.
An Inconvenient Truth – It would be recommended to watch the whole documentary ““An Inconvenient Truth A Global Warming”, however, if you cannot locate the movie, you may also watch the short video clips of the documentary at youtube.com Al Gore on Global Warming (9:58)
Assignment 2 Submission:
Type this assignment using a word processing program and save as a file. If you are using a word processing program other than Microsoft Word, then please save the file as Rich Text Format.
Submit your assignment by clicking on the Assignment 2 Submission link in the Course Content menu on the left and uploading your assignment.
Assignments include both questions and essay(s) related with the article covered and the ideas discussed in the course notes.
You need to review both article and lecture notes to answer the following questions.
Briefly describe the greenhouse effect. What human activities are impacting natural cycle of greenhouse effect? Any examples?
As described in “A Safe Operating Space for Humanity,” describe planetary boundaries generally and explain why they are important.
What are the branches of scientific enquiry that the authors of “A Safe Operating Space for Humanity” have used in their study of planetary boundaries?
Based on class notes describe environmental and health impacts of coal combustion and research their relation to the climate change.
What is the delicate balance described in the article?
Explain why the humanity has the freedom to pursue long-term social and economic development as long as the thresholds are not crossed?
According to scientists oceans are warming much faster than previously calculated values due to technologies available today such as wireless temperature sensors that can measure ocean temperatures in very deep waters and send the data to computer systems precisely. This may cause frequent hurricanes and storms that may devastate costal areas. Similarly harsh temperature changes in Midwestern states may induce more frequent draught and flood cases as well as tornados and storms than ever before. If global warming and climate change become serious public concerns in your hometown or in general in Iowa, what might be your response to resolve and help reduce the environmental impacts of it?
What are the challenges? Provide examples and offer methods to resolve the issue(s).
Powered by Beeline Reader