Why are people worried about increasing CO2 in the atmosphere? CO2 is a greenhouse gas Greenhouse gases trap heat in the atmosphere Trapped heat causes climate change Climate change is expected to bring about an increase in extreme weather events such as hurricanes, drought and flooding, as well as a rise in sea levels.
Which picture (A or B) shows the Greenhouse Effect?
Mitigation through increasing Carbon sinks- Afforestation (planting trees) Increase oceanic biomass (controversial) Decreased energy use Renewable energy sources, e.g. solar, wind Sequestration (e.g. injecting Carbon into lithosphere)
Carbon monoxide (CO) A colourless, odourless gas that is very poisonous. Comes from combustion of fossil fuels, e.g. vehicle tailpipes, smoke stacks, gas stoves A precursor to greenhouse gases Carbon monoxide elevates the concentrations of methane (a powerful greenhouse gas) and ozone in the atmosphere. CO eventually oxidises into carbon dioxide.
Nitrogen oxides (NOX) 2 MOLECULES - nitric oxide (NO) and nitrogen dioxide (NO2) NO2 is more toxic than NO Occurs naturally from lightning strikes, bacteria and volcanoes Manmade sources includes fossil fuel combustion (transport & power generation) & agriculture (esp. synthetic fertilisers)
A house painter affected by chronic lead poisoning. Wasted muscles and wrist drop are tell-tale symptoms of lead poisoning. http://www.osh.dol.govt.nz/kidz/gore/lead.shtml
Particles Dust Pollen Sea salt Viruses Bacteria
The smaller the particle, the more easily it can be inhaled into the body and cause problems. Particles with a diameter less than 10µm can be inhaled Particles can carry other pollutants, e.g. SO2 Particles can exacerbate respiratory illnesses such as asthma, hay-fever
Ozone O3 Good ozone (17-50km from ground level) –protects earth from harmful UV rays Bad ozone (below 17km-ground level) –can combine with water vapour to produce smog; causes respiratory problems, skin inflammation and can also decrease plant productivity
CFCs Chlorofluorocarbons Used as coolants, insulation and propellants in aerosols, foam and refrigerants (known a “Freons”) CFCs remain in troposphere for a long time Eventually CFCs find their way to the stratosphere where the UV rays cause the Cl to destroy countless O3 molecules This process has resulted in a huge hole on the ozone layer CFCs can also cause sore eyes, dry skin & irregular heartbeat CFCs are banned in the UAE from January 2010
Methane CH4 Colourless, odourless Methane is over 20 times more effective in trapping heat in the atmosphere than carbon dioxide (CO2)
Where does Methane come from? Anaerobic decomposition of organic matter in soils & landfill Coalmining Agriculture Wastewater treatment Natural gas (methane is the primary constituent)
Indoor air pollution Pollutants can be more concentrated indoors than outdoors. Build up of indoor pollutants can cause “sick building syndrome” Indoor pollutants can come from paints, sprays & solvents, electrical equipment & printers Volatile organic compounds (VOCs) can result in eye, nose, and throat irritation; headaches; loss of coordination; nausea; damage to liver, kidney, and central nervous system; cancer. Good ventilation is essential.