Unit 2 - Global Climate - Vulnerability and Resilience Flashcards
What does the atmosphere consist of and how big is it?
- mixture of solids, liquids and gases
- up to a height of around 80km
- consists of nitrogen, oxygen, argon and a variety of other trace gases such as carbon dioxide, helium and ozone - also water vapour and solids such as dust, ash and soot
How does temperature vary in the atmosphere?
- temperatures fall with height
What is the atmosphere?
- an open energy system receiving energy from both the Sun and Earth
What is insolation (atmosphere)?
- incoming solar radiation
What does solar energy drive?
- all weather systems and climate
What is radiation?
- the emission of short waves and long waves; as the Sun is a very hot body, most of its radiation is in the form of very short wavelengths such as ultraviolet and visible light
What is convection?
- the transfer of heat by the movement of a gas or liquid
What is conduction?
- the transfer of heat by contact
What happens to the solar energy?
- 46% is absorbed by the earth
- 22% drives the hydrological cycle
- 1% powers the winds and ocean currents
- 31% is reflected into space
What happens to the short-wave radiation (46 units) that reaches the ground?
- 14 are re-radiated as long-wave radiation to the atmosphere and to space
- 10 units pass to the atmosphere by conduction or the lower atmosphere only - since air is a poor conductor of heat
- 22 units are transferred by latent heat - the heat energy used by a substance change form but not temperature
From where is the atmosphere largely heated?
- from below
What is the greenhouse effect?
- most of the incoming short-wave radiation is let through the atmosphere, but CO2 traps the outgoing long-wave radiation, warming the atmosphere
What does the amount of insolation the Earth receives depend on?
- angle of the Sun (high - more solar radiation)
- type of cloud type (far from Earth and/or thin/no clouds - more solar radiation)
What does long-wave radiation refer to?
- the radiation of energy from the Earth into the atmosphere
What is the greenhouse effect?
- the process by which certain gases (greenhouse gases) allow short-wave, solar radiation to pass through the atmosphere but trap a proportion of outgoing long-wave radiation from the Earth
Why is the greenhouse effect a good thing?
- without it, there would be no life on Earth
How much have carbon dioxide levels risen from 1950 to 2015?
- have risen from 315ppm to 400pm
- are predicted to reach 600pm by 2050
What is the most common greenhouse gas?
- water vapour
- accounts for about 95% of greenhouse gases by volume and for about 50% of the natural greenhouse effect
What is the increase in carbon dioxide levels caused by?
- due to human activities, such as burning fossil fuels and land-use changes such as deforestation
How much does carbon dioxide account for in the greenhouse effect?
- 20%, but an increased proportion of the enhanced greenhouse effect
What is the second-largest contributor to global warming?
- Methane
- its presence in the atmosphere is increasing at a rate of 1% per annum
How much methane do cattle emit into the atmosphere per year?
- 100 million tonnes a year
- cattle convert up to 10% of the food they eat into methane
How much methane do paddy field emit into the atmosphere per year?
- 150 million tonnes a year
What are chlorofluorocarbons (CFCs)?
- man-made chemicals that destroy ozone as well as absorbing long-wave radiation
- increasing at a rate of 6% per annum
- up to 10,000 times more efficient at trapping heat than CO2
What is planetary albedo?
- reflection from the Earth’s surface
What is global dimming?
- the cooling of air temperature due to pollution
How does polluted air cause global dimming?
- polluted air has more sites for water to bind to
- the droplets formed tend to be smaller than natural droplets
- many small water droplets reflect more sunlight than fewer large droplets, so polluted clouds reflect far more light back into space
Where may the impacts of global warming be greatest?
- in tundra environments
What is the enhanced greenhouse effect?
- the impact of increasing levels of greenhouse gases in the atmosphere due to human activities
- more frequently called global warming
What does global climate change refer to?
- the changes in the global patterns of rainfall and temperature, and the incidence of droughts, floods and storms, resulting from changes in the Earth’s atmosphere, caused mainly by the enhanced greenhouse effect
What is the increase in greenhouse gases linked to?
- industrialisation
- trade
- globalisation
Which countries are the main contributors to greenhouse gas emissions?
- HICs
- but LICs and NICs are actively industrialising
What are the predicted effects on global warming?
- sea levels will rise, causing flooding in low-lying areas
- storm activity will increase
- agricultural patterns will change
- less rainfall over the USA, southern Europe and the CIS member states
- up to 40% of wildlife species will become extinct
What is the potential impact of temperature on ice and snow (environmental feature)?
- melting of polar ice caps and glaciers
What is the potential impact of temperature on coastlines (environmental feature)?
- increase in sea level causing coastal flooding
What is the potential impact of temperature on water cycle (environmental feature)?
- increased flooding; more rapid circulation