Global Issues Part 2 Flashcards
What is the spectral energy density?
it is the distribution of radiation energy emitted by a body across the electromagnetic spectrum.
What are the units of spectral energy density?
W m-1 or W Hz -1
What is a black body?
A black body absorbs all radiation that it may receive at any wavelength. It can be shown that such a body must emit radiation with an intensity and a SED that only depend on the Stefan-Boltzmann law.
On the diagram of spectral density - which hand side is the radiation emitted and received for the Earth
For spectral energy density, the radiation is received from the sun on the left hand side of the diagram. The radiation is transmitted to space on the right hand side of the diagram.
What is radiative forcing?
Most of the solar radiation hitting the earth will be in the form of visible light. Some will be reflected and scattered. The rest of it is absorbed by the surface and re-radiated in the infrared. The re-absorption of this re-radiated energy in the IR by some gases in the atmosphere delays re-emission back to space. The re-absorbed energy is re-radiated by the gases in al directions, thus warming the layers below. This is radiative forcing.
Which gas is mostly responsible for radiative forcing and other gases that contribute?
CO2. The less-contributing gases include water vapour, methane, nitrogen oxides and other gases.
What is the effect of a temporary increase in the CO2 concentration?
It reduces the heat flux that Earth is emitting to space.
What gives CO2 its dominance amongst other GHGs?
It has a fairly low concentration but the broad absorption band in the infrared spectrum gives its dominance.
What about water vapour and radiative forcing?
The rising temperature is increasing the overall concentration and thus amplifies the radiative forcing. However more clouds will then reflect sunlight back to space and thus mitigating the greenhouse gas effect.
What is the carbon bubble?
When looking at future prospects, the current value of fossil fuels may be seriously overinflated as more governments and businesses get on board the climate change reduction train. That gap between what fossil fuels are actually worth and what they are valued at will grow.
What could governments do to discourage the use of fossil fuels?
The aim of governments is to make fossil fuels a “stranded asset” to be left untouched. This would be by enacting regulations and implementing taxes. Thus would devalue the shares in oil and gas companies.
What is the greenhouse gas to rival CO2?
CH4
How is CH4 produced by human activity?
- Rice cultivation
- Biomass burning
- Coal mining
- Natural gas production
What was the aim of the Kyoto Protocol?
The Kyoto Protocol aimed to reduce CO2 emissions by 5% between 1990 and 2012.
Did the Kyoto Protocol meet its aims?
No the Kyoto Protocol failed. The emissions increased by half.
What are the reasons between the failure of the Kyoto Protocol?
It was not ratified by the US and Australia. It was ratified by the UK, China and India but the latter two were committed only to improving their economy.
What is the successor of the Kyoto protocol?
The Paris Agreement
