Major anthropogenic sources of these gases:

Carbon dioxide

combustion of fossil fuels, deforestation

Methane

livestock, padi fields, landfill sites (due to anaerobic bacteria), produced by forming of fossil fuels and released ventilation of coalmines, leaks from natural gas fills and oil pipelines

oxides of nitrogen

reaction of oxygen and nitrogen at high temperatures in vehicle engines and power stations

CFCs

aerosols, fire extinguishers, refrigerants, solvents, expanded foam plastics

Tropospheric ozone

Produced during the photochemical breakdown of NO2 and the subsequent reaction the oxygen

Gas Approximate relative effect per molecule

Carbon dioxide 1

Methane 30

Tropospheric ozone 2000

Nitrous oxide 160

CFCs 25 000

likely consequences of global climate change

sea level rise:

increased temperature cause water to expand
increased temperature cause land ice to melt , flow into the sea and increase the volume of the sea

Climate in change,

Most climate systems are driven by energy from the sun. Retention of more energy in the atmosphere my change these systems :

wind patterns - changes in velocity, frequency and direct
precipitation - higher temperatures increase evaporation rates which will increase precipitation rates. Water vapour will be transported by wind and result in precipitation when the air cools sufficiently. Changes in wind patterns may result in areas getting more or less rain.

Ocean current changes

El nino changes in the Peruvian current may become more frequent. Increased amounts of cold freshwater from melting glaciers may cause the gulf stream to slow and have less of a warming effect on North West Europe.

ecological changes

Temperature increase may cause growth rates of plants to increase

precipitation changes may cause wetlands to enlarge or shrink

oak trees have deeper roots than beech trees and can survive droughts better

Dormouse hibernation maybe disturbed by warmer winters and cause them to use stored fat and give them less chance of survival

Timing of ecological events; flowering, nesting and migration may change. Survival of interdependent species may be reduced e.g; if pollinating insects aren't present when flowers are produced

Consequential changes in species distribution and extinction of species that cannot colonise suitable new habitats

	Creado por spoopy Gonzalez hace casi 9 años

rewriting the teachers notes

Teachers Notes