Climate Change - Causes and impacts

Climate and weather

Weather-the daily changes in pressure, temp and precipitation at a local level

Climate-‘average’ weather over the long term (e.g. years) often at a regional level

Both are affected by - Ocean and atmospheric circulation systems,GHGs,Volcanic activity,Feedback cycles

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Climate change

LONG TERM CHANGE IN THE CLIMATE

Fluctuations in solar insolation( amount of solar radiation reaching) Affecting temperature

Changing proportions of gases in the atmosphere

Ocean and atmospheric circulatory systems-Energy from the equator is transferred toward the poles through atmospheric and ocean circulation systems.
Ocean circulation systems are caused by winds and difference in water temperature and salinity.


Wind occurs as a result of differences in air pressure.movement of air from high to low pressure (replacing rising air) creates wind.


MENTION EL NINO effects.

GHGs trap heat and increase the temperature. Anthropogenic activity increases GHGs in the atmosphere. Global Warming Potential(GWP) - It is a relative measure of how much heat a known mass of GHG traps over a number of years compared to same mass of carbon dioxide.GWP of CO2 is 1 and methane 21.READ abut methane in Oxford-page 326

Volcanic activity- short term effect ,Emissions from volcanic activity include ash and gases such as sulphur dioxide. The latter reacts in the atmosphere forming a sulphate aerosol that reflects solar radiation back into space and causes global cooling.Evidence- Ash from Mt. Pinatubo, in the Philippines on 15 June 1991 led to a cooling of the earth for about three years.

FEEDBACKS

Positive - WATER VAPOUR .MORE TEMP,MORE WATER VAPOUR ,MORE TEMP..CYCLE CONTINUES. ALSO ICE ALBEDO(REFLECTION by ICE),PERMAFROST MELTING produces methane.IT is a GHG

NEGATIVE-Plant photosynthesis
If temperatures increase, levels of plant photosynthesis can rise and more carbon dioxide is absorbed. This reduction in overall atmospheric levels of carbon dioxide results in a reduction in global temperature

IMPACTS OF CLIMATE CHANGE

ENVIRONMENTAL

ON SOCIETY

ON BIOSPHERE and ECOSYSTEMS

ON LAND

ON SEA LEVEL

HEALTH

ECONOMY

Impact on Agriculture and fisheries

ON GLOBAL TEMPERATURE

Water resources

ENVIRONMENTAL REFUGEES

COASTAL CITIES