4.4 Climate change Flashcards
What do greenhouse gases do?
Absorb and emit long wave radiation, thus trap and hold heat in the atmosphere
How much of the atmosphere do greenhouse gases make up?
Less than 1%
What are the two greenhouse gases with the largest warming effect?
Water vapour and carbon dioxide
How is water vapour created?
Via evaporation and transpiration of water bodies
How is water vapour removed?
Via precipitation
How is carbon dioxide made?
By cell respiration and burning fossil fuels
How is carbon dioxide removed?
Via photosynthesis and absorption by oceans
What is two other greenhouse gases?
Methane and nitrogen oxides
Where is methane emitted?
Waterlogged habitats, landfills and gas waste product of ruminants
How are nitrogen oxides released?
Naturally by certain bacteria and in exhaust by certain vehicles
What is the most abundant greenhouse gas in the atmosphere?
Water vapour
What are the two factors which determine how much of an impact a greenhouse gas will have in warming the atmosphere?
Ability to absorb long wave radiation
Concentration within the atmosphere
Why is the ability to absorb long wave radiation a determining factor in the impact of a greenhouse gas?
Gases that have a greater capacity to absorb long-wave radiation will have a greater warming impact
Why is the concentration within the atmosphere a determining factor in the impact of a greenhouse gas?
The greater the concentration of a gas, the greater its warming impact will be within the atmosphere
What determines the concentration of a gas?
It’s rate of release and persistence in the atmosphere
Why is human activity increasing the impact of greenhouse gases?
Because it is increasing the amount of greenhouse gases
What is the atmospheric lifetime of water?
1-5 days
What is the atmospheric concentration of water?
0.01-4%
What is the atmospheric lifetime of carbon dioxide?
5-200 years
What is the atmospheric concentration of carbon dioxide?
385 ppm
What is the atmospheric lifetime of methane?
12 years
What is the atmospheric concentration of methane?
1797 ppb
What is the atmospheric lifetime of nitrous oxide?
120 years
What is the atmospheric concentration of nitrous oxide?
322 ppb
What is the greenhouse effect?
A natural process where the atmosphere acts like a greenhouse to trap and retain heat
What does the greenhouse effect ensure?
That earth maintains the moderate temperature needed by organisms to maintain life processes
What would happen without a greenhouse effect?
Earths temperature would drop significantly at night in the absence of direct sunlight
What does the greenhouse prevent?
Rapid temperatures fluctuations
What type of radiation is the radiation from the sun?
Shorter wave radiation
What does the surface of the earth absorb?
Short wave radiation
What does the earth re-emit the short wave radiation as?
Loger wavelength radiation
How do greenhouse gases retain the heat within the atmosphere?
They absorb and re-radiate the longer wave radiation
What is happening to greenhouse gases?
Man is increasing their emission via multiple activities
What are the three main activities fuelling greenhouse gas emission?
Deforestation
Increased agriculture
Combustion
How is deforestation contributing to greenhouse gas emission?
The removal of trees means less carbon dioxide is being removed from the atmosphere via photosynthesis
How is increased agriculture contributing to greenhouse gases?
It clears land for cattle and ruminant cattle produce methane
What greenhouse gas is increasing most rapidly?
Carbon dioxide
What is the main reason carbon dioxide is rapidly increasing?
Combustion
What happens when fossil fuels are combusted to release energy?
Carbon dioxide is released as a by product
What has the increased reliance on fossil fuels since the Industrial Revolution resulted in?
38% increase in CO2 levels
How are efforts being made to reduce our reliance on fossil fuels?
By exploiting alternative energy sources
What do greenhouse gases play a pivotal role in determining?
Global temperatures and climate patterns
Why do greenhouse gases help determine temperatures and climate patterns?
Due to their capacity to retain heat
What should correlate with an increase in global temperature?
Increases in greenhouse gas concentrations
What may long term weather patterns be influenced by?
Greenhouse gas concentrations
What do scientists predict an increase in greenhouse gas concentrations will lead to?
An enhanced greenhouse effect
What will an enhanced greenhouse effect cause?
- more extreme weather conditions
- more droughts/heavy rainfall
- changes to ocean currents
How was the link between global temperatures and carbon dioxide concentrations established?
By analysing data over a long time period
What do ice cores taken in Antarctica provide evidence of?
The environmental conditions at the time of freezing
How do they work out historical co2 levels and air temperatures from the ice cores from the vostok station?
By analysing the gas bubbles trapped in ice
From the vostok ice core, what is there a strong positive correlation between?
Carbon dioxide concentrations and temperature
What do the fluctuating cycles of Co2 concentrations correlate with?
Global warm ages and ice ages
What significantly increased mankind’s use of fossil fuels?
The industrial revolution
What is there a strong positive correlation with increasing fossil fuel emissons?
Rising atmospheric concentrations of CO2
What does an increase in atmospheric carbon dioxide concentration correlate with?
An increase in average global temperature
What evidence backs up “Climate has changed in the past and current trends merely reflect the Earth’s natural climatic cycle”?
Data collected from vostok ice core show several changes in climate over the last 400,000 years.
And at several points in history global temperatures have been warmer than those currently
What are a counter argument to “Climate has changed in the past and current trends merely reflect the Earth’s natural climatic cycle”
- whilst climate change happens naturally, its not normally this abrupt
- when global warming occurred abruptly it was destructive to life
What is evidence for “Climate change is being caused by solar activity and the effect of greenhouse gas emissions is negligible”?
Temperatures are influenced by the amount of solar radiation from the sun
- warmer temperatures are caused by an increase in solar irradiance
What are counter arguments to “Climate change is being caused by solar activity and the effect of greenhouse gas emissions is negligible”?
In the last 35 years the sun has cooled but global temperatures increased
There is no evidence of correlation between solar irradiance and global temperature
What evidence supports “Certain changes in climate conditions cannot be linked to greenhouse gas emissions”?
Sea levels rose before greenhouse gases increased following the industrial revolution
What is counter arguments against “Certain changes in climate conditions cannot be linked to greenhouse gas emissions”?
The pattern of change in sea levels is influenced by the period of time of when data is collected
The rate of sea levels rising is greater in the last 30 years that the last 200
What evidence supports “Variability between predicted climate change models means that such models are unreliable”?
Three different models show variation of more than 5C
Climate change models are made on assumptions and if the assumptions are false the prediction will be incorrect
What are counter arguments to “Variability between predicted climate change models means that such models are unreliable”?
All models predict an increase in average global temperatures over the next 100 years
The assumptions made by the different models relate to the extent of human activity over the next 100 years
What evidence supports “Increases in greenhouse gas concentrations in the atmosphere will not be enough to cause significant climate change”?
In 2009 there were only 39 molecules of co2 per 100000 molecules in the atmosphere, it will take mankind another 5 years to add one molecule.
Whilst the number may double by the end of the century it still produces a small number
What is the counter arguments to “Increases in greenhouse gas concentrations in the atmosphere will not be enough to cause significant climate change”?
Carbon dioxide is important to the environment cause there is so little of it
Living things need homeostasis and small external changes can have big impacts on viability
