Atmosphere 2- climate change and air quality Flashcards
What type of radiation is emitted by all objects?
electromagnetic
What is the spectrum of electromagnetic radiation emitted determined by?
temperature of the object
What does a higher temp do to wavelength?
results in a shorter wavelength
What would the temp of earth be without greenhouse effect?
~-20*c
What is the greenhouse effect?
the increase in the surface temperature of the Earth as a consequence of the presence of an overlying atmosphere
What does the greenhouse effect arise as a result of?
Temperature dependence of emission spectra (Earth vs. Sun)
Differing absorption properties of Earth’s atmosphere towards Visible / IR radiation
What wavelength is most incoming solar radiation?
visible wavelength
What wavelength is most outgoing terrestrial radiation?
Far IR (infrared) wavelength
What is the absorbance of atmospheric constituents like in relation to IR?
Absorb more IR than visible light
What are some examples of greenhouse gases?
H2O
CO2
CH4
NO2
How would earth be described without the greenhouse effect?
Snowball- completely frozen
What is radiative forcing (RF)?
measure of the influence that a factor has in altering the balance of incoming and
outgoing energy in the Earth-atmosphere system
What does positive and negative radiative forcing tend to be like?
Positive- warm the surface
Negative- tends to cool surface
How is radiative forcing expressed?
W m*2
How is radiative forcing calculated?
off pre industrial levels from 1750
What is the IPCC?
Intergovernmental panel on climate change
What is the radiative forcing value of CO2?
+1.7
What would radiative forcing be when adding up individual factors for global effect?
+1.6 W m*2 (warming)
What does a decrease in tropospheric ozone lead to? (RF)
cooling
What is an aerosol?
suspension of particles and the gas it is suspended in
What can particles in the atmosphere do and what is the effect?
Absorb= warming
Scatter= cooling
What do raindrops like to have to form?
A condensation nuclei or surface (particles)
What does more particles in the atmo lead to?
more particles = smaller droplets
What are the 1st and the 2nd indirect affects of particles in the atmo?
1st- brighter cloud, higher albedo, more reflection
2nd- longer last clouds
What is the cooling effect of particle clouds like?
Large and uncertain
How are nitrate and sulphate particles produced?
combustion emissions + processing
How are atmospheric organic compounds produced?
vegetation emissions + processing
What do reductions in pm2.5 cause?
Air quality benefit
Climate cost
How is black carbon/ soot produced?
incomplete fuel combustion
What are the main sources of black carbon?
vehicle emissions- diesel
any in-efficient combustion
What does black carbon do with solar radiation?
efficiently absorbs it leading to warming
What will happen to air quality and climate from black carbon emissions?
Benefit for both
WHat can be done to make people switch from petrol to diesel?
making the price of diesel less than petrol
What is the benefit of diesel over petrol?
Improved fuel economy
Lower CO2 emissions
What is the negative of diesel over petrol?
higher air pollution emissions
More NO2 and PM
Worse for health
What is the effect of changing from petrol to diesel on air quality of climate?
bad for air quality good for climate
What will happen to co2 emissions with a shift from petrol/diesel to EV?
will be reduced (depending on source of electricity)
What will happen to NO2 emissions with a shift from petrol/diesel to EV? (with benefits)
Reduced NO2 emissions (from tailpipe)
Urban Air Quality & Health Benefit
How does tropospheric ozone form?
VOCs + NOx + sunlight——- Ozone
What does a reduction in VOCs (methane) and Ozone do for air quality and climate?
benefit for both
