Climate Change Effects on Atmosphere

• Anthropogenic changes


  Changes resulting from human activities
• Consequences of global warming


  rising sea levels, distribution and species changes within animals, temperature change, migration and biodiversity changes
• Ecological changes due to climate change


  -species may be directly effected by temperature

  -plants may grow faster, disrupting toxin reales times, killing caterpillars

  -precipitation changes may cause wetland to enlarge or shrink

  -deep rooted trees will survive over shallow rooted trees

  -seasonal events are changing time; flowering, migration, nesting- this threatens animals that are dependent on these events

  -distribution of species may change as they find new places to live
• Changes in climatic processes


  Wind pattern changes

  -winds may change velocity, frequency and direction

  -stronger winds will cause more damage

  -if the direction changes rain will fall in different areas

  Rainfall Patterns

  -higher temperatures will increase evaporation rates, resulting in more precipitation

  -areas where it did rain may receive less as it is to warm to condense
• Changes in Cryosphere


  - Reductions in the amount and duration of snow cover

  - Changes in the extent and speed of movement of land ice

  - Loss of ice shelves

  - Changes in ice thickness and area

  - Decreases earths albedo effect

  - Ice and snow fed rivers may experience flooding
• Sea level rise


  Thermal expansion of seawater

  -sea water expands with heat, causing the sea level to rise

  -although it takes a long time for oceans to heat

  Melting land ice

  -more water flows into the sea
• Changes in ocean currents


  Ocean currents distribute heat around the world

  Can have a big effect on the climate on land as water warms or cools the coastal land areas and the atmosphere
• Impacts of climate change on humans


  Health

  -heatwaves cause health problems

  -food poisoning may become more common as pathogens can grow more rapidly

  Water supply

  -changes in evaporation, precipitation and rice flow may create water problems

  Food supply

  -changes in temperature and water availability will limit what can be grown

  Impacts on infrastructure

  -tar roads may melt

  -rail track can expand and buck (27 degrees)

  Landslides, drainage problems and bridge damage
• Difficulties of monitoring and predicting climate change


  • limited historical data used to reconstruct past climate conditions (ice cores, tree rings, historical accounts)

  • future climate predictions are made using computer climate models which use different variables

  • climate feedback mechanisms are not fully understood

  • time delay between cause and effect

  • uncertainty over the use of some data in drawing conclusions has resulted in differences in scientific and political opinion
• Data Collection Methods


  Historical data, proxy data, ice core data, satellite, computer models
• negative feedback system


  A reaction that causes a decrease in function in response to some kind of stimulus
• Positive feedback system


  a process that results in a response that enhances the original stimulus
• example of negative feedback


  Increase in photosynthesis- high temperature increases rate of photosynthesis which removed CO2 from atmosphere

  Increased low-level cloud- high temperature increases evaporation, which leads to increase condensation and produces more clouds
• examples of positive feedback


  -warming increases rate of decomposition, causing more CO2 to be released and therefore more warming

  -it has a high albino effect, so incoming sunlight is reflected and not absorbed, therefore increasing the temperature of the atmosphere
• Tipping points


  the minimum amount of change within a system that will destabilize it and cause it to reach a new equilibrium or stable state.

  
  

  Characteristics

  -positive feedback

  -changes are long lasting

  -changes are hard to reverse
• Control of global climate change


  Carbon sequestration- planting more trees

  Carbon capture and storage- a developed technology that may remove carbon dioxide produced by industrial processes and stored in depleted oilfields and aquifers

  Geo engineering- technology that could control natural processes to reduce anthropogenic greenhouse effect

  -painting houses white, increase albedo

  -putting solar shades in orbit to reduce sunlight reaching the earth

  -adding nutrients into sea to stimulate plankton growth
• Anthropogenic


  Human-induced changes on the natural environment
• Carbon dioxide- how to emit less


  -reduce use of fossil fuels

  -use renewable energy

  -carbon sequestration, planting more trees
• Methane- how to emit less


  -reduce livestock production

  -amount of rubbish in landfill

  -improved recovery of gas from coal mines
• Oxides of nitrogen- how to emit less


  -use of catalytic converters in vehicles

  -increase use of public transport
• Chlorofluorocarbons- how to emit less


  -use alternative materials which replace CFCs, such as butane, propane, alcohol
• Troposphere ozone- how to emit less


  -controls and processes that reduce emissions of Nox

  -reduce the formation of ozone in the troposphere
• Adapting to climate change


  Flood control- building riverbanks or coastal defences

  Managed retreat- leaving areas to take natural course as managing it is too expensive

  Urban drainage control- permeable urban surfaces

  river flow management

  raised buildings

  floating houses
• Kyoto Protocol (1997)


  An agreement legally binding signed-up countries to meet emissions regulation targets if all greenhouse gases by 2012 relative to 1990 levels
• El Niño


  Winds that blow opposite to normal trade winds- sending warmer waters to South America causing rainfall and colder waters to Australia/Asia causing drought

  This changing current stops the nutrient boom vital for large food webs to replenish and source food
• La Niña


  Trade winds that blow strongly in the Normal direction- sending warm waters to Australia/Asia causing rainfall and cold currents to America causing droughts
• Ozone Depletion


  thinning of Earth's ozone layer caused by CFC's leaking into the air and reacting chemically with the ozone, breaking the ozone molocules apart
• Chlorofluorocarbons (CFCs)


  Greenhouse gas that absorbs infrared effectively heating the earths surface
• How do chlorofluorocarbons affect the ozone layer?


  -in the atmosphere they decompose to give chlorine atoms

  -chlorine reacts with O3 creating O2 and ClO, causing a hole in the earth's ozone layer
• Ozone Layer


  -in stratosphere

  -10 to 50 kilometres above earths surface

  -absorbs UV
• Evidence of ozone depletion


  -measuring ozone using the Dobson unit

  -ground based data collection at the Antarctica, Halley Station

  -satellite surveys

  -air samples from the stratosphere, collected by the helium balloons

  -ozone depletion over Antarctica, polar vortex
• Montreal Protocol (1987)


  International agreement to phase out the manufacturing and use of CFCs and other ozone depletion substances
• Disposal of waste CFCs


  -> drained and

  -> broken down to Co2 and acidic gases

  -> acidic gases neutralise with crushed line
• Alternative materials for CFCs


  -HFA (hydrofluoroalkanes) replacing CFCs in asthma inhalers

  -propane and butane replacing CFCs in aerosol propellants

  -CFC solvents- replaced by alcohol and HCFC
• HCFCs replacing CFCs


  -less chemically active

  -do not reach the stratosphere, breakdown in troposphere
• HFCs replacing HCFCs


  -do not contain chlorine

  -expensive and done work as well as CFC

  -contributes to global warming