7.10 Global warming

Protective layer of gases around Earth called the atmosphere

• essential for life - acts as insulating blanket

• Sun’s heat energy (light rays) passes through atmosphere & hits earths surface

  • some energy absorbed & heats ground

  • Most energy is re-emitted or reflected back into the atmosphere

    • the radiation hits particles of gas in atmosphere & the energy is absorbed

    • The particles re-emit the energy in random directions

• This process keeps Earth at warm & stable temperature

• The gas particles include: carbon dioxide, methane, & water

  • greenhouse gases

  • Essential for life, but responsible for global warming

Global warming

• as greenhouse gases accumulate in atmosphere & greenhouse effect strengthens, earth warms up (global warming)

Climate change

• effects of global warming

• Climate means long term weather patterns

Consequences

• Rare weather events (droughts, hurricanes, floods) will become more common & more severe

• Sea level rise

  • ice melts

  • Water in oceans expand as it warms up (volume increases)

• Rise in sea levels will cause seasonal flooding & submersion if entire islands & coastal towns

  General impacts:

• Organisms adapted to environment may not survive due to changes in environment

• Some species are gradually moving to the poles where it’s cooler

• Biodiversity likely to fall dramatically in next few decades