Unit 2 - Global Climate Flashcards
Natural Greenhouse Effect
Process by which certain gases (such as water Vapor, CO2, Methan (CH4) and Chlorofluorocarbons) allow short wave radiation from the sun to pass through he atmosphere but trap and increasing proportion of outgoing long-wave radiation.
Insulation definition
Incoming solar radiation
What percentage of insulation is absorbed by atmospheric gases, absorbed by the surface, and reflected?
20% absorbed by atmospheric gases
50% absorbed by the surface
30% reflected
How does global dimming occur?
- volcano eruption —> tiny particles suspended in the atmosphere
- absorb and reflect radiation (less evaporation and precipitation)
- THEREFORE cool down!
What are some variations in solar radiation?
- Solar evolution (as the hydrogen is used up, it is marginally getting hotter each year)
- Earth’s orbit - sometimes closer to the sun, more insulation
- Sun spots - dark areas on the sun, zones of lower temperature
The feedback loop of melting permafrost (5 steps)
- Temperature rise
- Polar ice/permafrost melts
- Darker surfaces revealed
- Albedo reduced (less reflection)
- More solar radiation absorbed
Albedo definition
The proportion of insulation reflected by the earth’s surface (ice has high, soil has low)
Causes of the enhanced greenhouse effect (5)
- Fossil fuels
- Deforestation
- Economic activities
- Fertilizers
- Chlorofluorocarbons and Hydrofluorocarbons
Fossil fuels examples - Enhanced greenhouse effect
Which GHG does it produce?
How much of the emissions are absorbed by plants and the oceans?
Coal, petroleum, oil, natural gas
Carbon Dioxide (CO2)
Half of emissions absorbed by plants and the oceans
Other half in the atmosphere
How does deforestation contribute towards global warming? (2)
- Decaying dead vegetation (CO2 released)
- Less trees to absorb carbon dioxide (photosynthesis)
How is methane gas produced in cattle raising?
methane gas produced by bacteria in animals’ stomached as a by-product of digesting grass or grain
Externalities definition + 1 example
Consequences of economic activities that affect other parties without being reflected in market prices (ex. Air pollution)
How does globalization cause more externalities, thus more global warming?
Locally based companies attracted to produce in country with weak environmental standards, low taxation rate, low labour costs (China or Mexico)
—> cheaper for company
—> environmental costs, air pollution, consumption of fossil fuels (underlying externality costs that the company does not need to care about or pay for)
Hydrosphere definition
The Earth’s water (whether in solid, liquid, or gaseous form)
—> movement with water cycle
Biosphere definition
Comprises of all living things on Earth
What percentage of ocean water is salty (not useable for drinking)?
97%
How are glaciers retreating?
Global warming, summers are hotter and winters are not cold enough to freeze it back to original state.
Effects of glaciers retreating (3)
- global rise in sea levels
- as the glacier’s supply of ice declines, there is less evaporation of water vapour and decline in precipitation
- exposes bare racks and soils that are vulnerable to erosion, rock falls, and landslides
Large carbon stores on Earth (2)
- Permafrost (frozen organic matter)
- Oceans
How does melting permafrost contribute towards the increase of carbon in our atmosphere?
Frozen organic matter thaws, decaying.
Releases CO2 or CH4, GHG.
Feedback Loop
Which extreme weather events have been increasing in incidence and severity due to climate change?
- Hurricanes —> coastal flooding
- Heavy precipitation events
- Droughts
Biome
World’s total collection of a particular type of vegetation community (rainforests, deserts, grasslands, tundras)