global climate change Flashcards
what is climate change
where the composition of the of the atmosphere is changed this impacts the physical and biological processes
what is human caused climate change called
anthropological climate change
is the greenhouse effect needed
yes as without it it would be too cold for life
how would temperatures be affected with the absence of the greenhouse gas effect
usually about 15c without it would be –17c
what are the 5 gases that cause anthropogenic and natural climate change
CO2
NOx
CH4
CFC
tropospheric ozone
what is atmospheric residence time
this is the life time of a greenhouse gas (GHG)
what are the 4 main impact areas of climate change
changes to the oceans
changes to the cryosphere
changes to climate processes
changes to ecological processes
what is another name for the North Atlantic conveyer
the gulf stream
what does the North Atlantic conveyor do
moves warm water from the equator to the NE towards Europe
what are the two main drivers to the NA conveyor
- winds that blow form the SW to the NE bow surface waters in that direction
- water in NE Atlantic is cooler therefore rapidly sinks pulls more water to replace it driving the current
How will a change to the gulf stream affect Europe’s weather
weather in Europe is partly caused by the gulf stream so if climate change affects this Europe’s weather could also be affected
how frequently does EL Niño occur
happens roughly every 2-7 years
what is happening to El Niño
change of global wind patterns becoming more extreme and frequent (maybe climate change)
What is la Nina
cooler/ normal conditions that should be experienced
what two reasons will cause sea level to rise
melting land ice
thermal expansion of water
How will melting land ice increase sea levels
ice will melt as land warms up this will flow out to sea increasing the volume of water in the oceans
does snow/ice have a high or low albedo
high
what is albedo
the reflective power of a surface the lighter the surface the more solar radiation it can reflect
what is a glacier
a body of compressed snow and ice that moves slowly with gravity downslope
what do warmer climates do to glaciers
cause them to ablate (melt) and therefore retreat upslope
how doe climate change affect ice shelves
causing a loss of ice
why doesn’t the melting of ice shelves add to sea level rise
they displace the same amount of water as they would add by melting meaning when they melt there is no net increase
what are ice shelves good at
good at holding back the ice behind
what happens when an ice shelf melts
the glaciers are more likely to move to sea level more quickly
How will climate change in the future
some areas will be wetter some will be drier but we don’t know the exact outcomes yet
what is the problem with the slowing jet streams
slower movement means that weather stays over a place for longer meaning prolonged rain (flooding) or heat waves (drought)
how much does water vapour increase for 1*c
7% for every degree of warming
What control methods are there for Carbon Dioxide?
Redction in fossil fuel use (energy conservation)
Use of energy resources with low carbon emission
Carbon sequestration (afforestation and carbon capture stations)
How can methane be controlled?
Reduciton in landfill waste (increased recycling, reduced food waste)
Reduced livestock produciton
Improved recovery of gas from coal mines and gas and oil facilities
what are the control methods for oxides of nitrogen?
Reduced use of internal combustion engines (using more public transport)
Catalytic converters in vehicle exhaust (converted in nitorgen and oxygen instead of NOx)
Addition of urea to power station effluents or diesil engine exhausts to reduce NOx concentration in nitrogen steam
what are the control methods for chloroflurorcarbons?
Alternative materials in manufacture and appliance operation:
- butane or propane in aerosol cans
- HFC’s and HCFCs in refrigerators
- alcohols as solvents for cleanig elctronic equipment
Use of alternative operational processes
- trigger and pump action sprays cleaners instead of aerosol cans
- stick and roll-on deoderants instead of aerosols
What are the control methods of tropospheric ozone?
controls and processes which reduce NOx emissions also reduce the formation of ozne in the troposphere
what does CCS stand for?
Carbon capture storage
What is CCS?
development of technology that may remove carbon dioxide produced by industrial processes
what are the main stages of CCS?
Capture CO2 or removal or carbon from fuel
Transport by road tanker/ ship or pipeline
CO2 storage in depleted oilfields, gas fields, aquifers or its use in secondary oil recovery
what are CFCs?
Chloroflurocarbons
when were CFCs developed?
1920’s
what were CFCs developed for?
air conditioning units
refrigerators
aerosol propellants
solvents for cleaning eletrical equipment
What properties meant CFCs were used?
-Boiling point close enough to ambient temperatures that gases can be liquefied to easily achieve pressure, so aerosols didnt need to be stong, compressors in refigerators didnt need to be powerful
- Ability to dissolve grease and oils but not damage electrical components
- CFCs not flammable
- Most non-toxic
what is the Rowland-Molina hypothesis?
1974, two american scientists suggested chemical properties of CFCs could lead to ozone depletion in stratosphere
What properties of CFCs worried Rowland and Molina?
Persistence
Dissociation by UV and release of chlorine
Reaction of chlorine and oxygen
Other halogens
Why is the persistence of CFCs a problem?
CFCs are chemically stable sso they remain in the atmosphere long enough to be carried up to the stratosphere
What is the problem with dissociaiton by UV and the release of chlorine?
CFCs are stable in troposhere
In startosphere CFCs exposed to higher UV levels
Absorb UV which breaks Carbon to Chlorine bonds and releases Chlorine free radicals
Why is the reaction of chlorine and oxygen a problem with CFCs?
Chlorine reacts with monoatomic oxygen preventing its reaction with O2 to form O3
Preventing formation of Ozone molecules
What is the montreal protocol?
Legally binding goals to protect the ozone
What were the main aspects of the montreal protocol?
- Manufacture and use of CFCs and other Ozone depleting substances phased out and banned
- Use of HCFCs phased out by 2030
- Essential uses of ozone-depleting substances still permitted ( halon for an extinguisher in air craft)
- fund is available to help implement protocol
what is ozone concentration in the stratosphere?
13 parts per million
where is the ozone located?
between 12-24km
what is the point of the ozone?
prevents most high energy UV radiation from reaching earths surface
what are the three types of UV?
A
B
C
what are the chracteristics of UV types?
A= not absorbed by Ozone or diatomic oxygen
B= almost Fully absorbed by ozone
C= fully absorbed by ozone and diatomic oxygen
what is the worst type of UV?
UV C as its the most damaging to cells
WHat is the Problem of UVB on living organisms?
Can be absorbed by living cells, which can cause skin damage, DNA damage, skin cancer,cataracts, leaf tissue damage, reduced photosynthesis
what marine organisms would be affected by UVB?
algae
corals
planktonic organisms
what is the unit for ozone?
Dobson units = DU
what are dobson units used for?
estimate total thickness of ozone if it existed as one layer of pure ozone at sea level
What would 1mm thick ozone by in dobson units?
100
what is normal ozone thickness in dobson units?
300
What does ozone hole = in dobson units?
220 or below
who collected first evidence of ozone depletion?
British antarctic survey at halley station in Antarctica due to evidence of high UV levels at groun level
How can satellite surveys measure UV levels?
higher then stratosphere so have to measure reflected UV, higher then usual readings hinted at depletion
How can air sampels be taken in the stratosphere?
helium ballons
highflying research aircraft
What did air samples from the stratosphere show? (ozone depletion- original research)
chemicals that were causing depletion, especially chlorine and chlorine monoxide
What is ozone variability?
concentration varies between different areas at different times and altitudes
Where is ozne depletions most severe in atmosphere?
altitude of 12-24km
where UV splits cfc molecules preventing ozone formation
Where in the world has worst ozone depletion occured?
Antarctica
sometimes drops below 100DU
What makes ozone depletion worse in antarctica?
the atmospheric conditions
atmospheric temperatures lower so ice crystals form (surface for reaction of cfc so greater loss)
what is the problem with ice crystals in the atmosphere?
provide surfaces on which chemical reactions take place producing chlorine molecules released from CFCs
What is the polar vortex?
winds around Antarctica which means chemicals from the globe go to Antarctica and get trapped
maintains low temperatures allowing ice crystals to form
Why is darkness a problem in Antartica? (CFC)
complete darkness in winter means when spring comes round sunlight splits the chlorine molecules which produce chlorine free radicals that cause depletion
what were the several causes for success of montreal protocol?
International recognition of the serious consequences of ozone depletion
agreement between nearly every country that action must occur
development of alternatives so most ozone-depleting substances are not necessary
