Section 3 Flashcards
What creates the natural greenhouse effect?
The water vapour in the atmosphere.
Which gases cause the enhanced greenhouse effect? How are they released into the atmosphere?
Carbon dioxide, methane, nitrous oxide.
They are released into the atmosphere through human activity.
What is GWP?
Global warming potential; it’s a measure of the relative ability to trap thermal energy in the atmosphere.
When measuring GWP, what gas is used as a reference for comparison to other GHGs?
carbon dioxide
What is the persistence of a gas?
How many years each gas will remain in the atmosphere.
How have ice core samples helped develop our knowledge about climate change?
The analysis of ice core samples (to give us an idea about the distant past) and atmospheric conditions have shown the levels of all three greenhouse gases in Earth’s atmosphere are increasing.
Since what time has the carbon dioxide level in the atmosphere been increasing?
Since the industrial revolution in the late 18th century.
What is a carbon source?
Any process that releases carbon into the atmosphere.
What are fossil fuels and what are they formed from? Why are they bad for the environment?
Fossil fuels are formed from the remains of living organic material, so they contain a lot of carbon. When burned, they release carbon dioxide and nitrous oxide into the atmosphere.
True or false: modern agriculture does not contribute to the level of greenhouse gases.
False
What are carbon sinks? Why has the amount of them been decreasing?
Things that remove carbon dioxide from the atmosphere; forests (photosynthesis removes carbon dioxide from the atmosphere). The human need for fuel and land for agriculture and industrialization has decreased the amount of carbon sinks.
How has the level of atmospheric carbon dioxide increased by 32% over the last 200 years?
The combination of increased use of fossil fuels and the decrease in available carbon sinks.
What are halocarbons? Where are they usually found?
They are another class of man made chemicals that can trap thermal energy in the atmosphere. they can be found in refrigerators and air conditioners.
Name four pieces of evidence for global warming (besides the increase of average global temperatures).
- flowers blooming earlier in the northern hemisphere
- more extreme weather events like ice storms and floods
- snow cover in polar regions decreasing
- increased avg. level and temp. of Earth’s oceans
What is the general circulation model (GCM)? What do they focus on?
- computer model of climate on a global scale
- GCM’s focus on the mechanisms of thermal energy transfer in the atmosphere, the complex factors that influence them, and how they are changing. These changes obviously have major implications for climate on different parts of Earth.
Describe the Montreal Protocol (1987)
- The Montreal Protocol, signed by 182 countries, controls the production and consumption of substances that can cause ozone depletion.
- CFC’s are to be phased out and replaced with hydrochlorofluorocarbons (HCFC’s), which destroy the ozone much more slowly than CFC’s.
- the first international agreement concerning the Earth’s atmosphere
What are chlorofluorocarbons?
Chlorofluorocarbons
(CFC’s) are substances that
deplete the ozone layer (are a type of halocarbon). Their use is now restricted.
Describe The United Nations Framework Convention on Climate Change (1994)
The Convention on Climate Change sets an overall framework for intergovernmental efforts to tackle the challenge posed by climate change. Supports sustainable development.
Under the Convention, governments:
- Gather and share information on greenhouse gas emissions, national
policies and best practices
- Launch national strategies for addressing greenhouse gas emissions and
adapting to expected impacts, including the provision of financial and
technological support to developing countries
- Cooperate in preparing for adaptation to the impacts of climate change
- near universal membership, with 189 countries having ratified
Describe the Kyoto protocol.
- 1988
- made under the United Nations framework convention
- industrialized countries will reduce their collective emissions of GHGs by 5.2% compared to 1990
- (compared to the emission/ levels that would be expected by 2010 with out the protocol, this is a 29% cut
Emission reduction credits
- given to a country for taking actions that contribute to the reduction of GHGs
- receive credits through various shared “clean energy” programs and “carbon dioxide sinks” in the form of forests and other systems that remove CO2 from the atmosphere
- left room for developing countries to increase their energy use (needed to grow their economies) but with the provision that they too will face restrictions in the future
- most counties signed/ratified (USA is an exception)
What is carbon dioxide sequestering (method of stabilizing greenhouse gas levels)?
Carbon dioxide sequestering is the process of capturing the exhaust from a fossil fuel combustion and pumping it back into Earth. The increase in pressure can be used to enhance the extraction of additional fossil fuels in nearby wells.
What is a concern related to carbon dioxide sequestering?
A concern is that carbon will not remain captive and would leak back into the atmosphere over a span of decades /centuries.
What gases does producing fossil fuels release?
Methane and carbon dioxide
Explain how agriculture contributes greenhouse gases to the atmosphere.
- nitrous oxide is released by the use of manure and chemical fertilizers
- methane is emitted from rice paddies and from the digestive systems of cattle and other animals
What is the enhanced greenhouse effect?
It is the change in Earth’s net radiation budget caused by the increase in human-generated greenhouse gases.
