Global Climate Change Flashcards
What is net radiative forcing?
The difference of insolation (sunlight) absorbed by Earth and energy and radiated back to space
What is the greenhouse effect?
Layer of GHGs in the atmosphere
Short wave radiation from the sun can go through the layer of gases
Short wave radiation is then absorbed by the Earth
Some is reflected back as long-wave
Long-wave cannot move through GHGs so it is trapped and re-radiated to Earth which warms it up
Increasing GHGs increases re-radiation
How much do GHGs contribute to warming?
CO2 = 66%
CH4 = 16%
N2O = 6%
CFCs = 8%
What causes the Keeling curve shape?
More vegetation in northern hemisphere than southern
More photosynthesis in spring/summer so CO2 levels decrease so line drops every year
More respiration and less photosynthesis in winter so CO2 levels increase so line goes up
This repeats every year
What are the main anthropogenic CO2 sources?
Electricity and heat
Transport
Manufacturing and construction
Buildings
So most from burning fossil fuels
What are the main anthropogenic CH4 sources?
Agriculture - rice is a large producer due to water logging
Fugitive emissions
Waste
Land-use change and forestry
What are the main anthropogenic sources of N2O?
Agriculture
Industry
Waste
Land-use change and forestry
What are the main anthropogenic sources of all the GHGs combined?
1 - Electricity and heat
2 - Transport
3 - Manufacturing and construction
4 - Agriculture
5 - Fugitive emissions
What are global warming potentials?
A measure of how much energy the emissions of one ton of a gas will absorb over a given period of time, relative to the emissions of one ton of CO2
What does GWP compare?
Compares the integrated radiative forcing over a specified period
