Why is global warming happening? Human activity is increasing the amounts of the greenhouse gases in the atmosphere, so more heat is trapped. The heating of the earth through human activities is called the ‘Enhanced Greenhouse Effect’ and this is causing the earth to heat up, or global warming. Global warming doesn’t just mean that the earth gets hotter, it means that the whole climate is changing.

Heat radiates from the earth Natural Greenhouse effect Enhanced Greenhouse effect Atmosphere has more greenhouse gases Heat radiates from the earth Less heat escapes to space Some heat escapes to space Atmosphere traps some heat Atmosphere traps more heat Some heat is trapped, some escapes, the earth is warm enough for life. More heat is trapped, less escapes and causes global warming

Which gases in the atmosphere trap heat? Greenhouse Gases trap heat. They make up less than 1% of gasses in the atmosphere Main GHG: Carbon dioxide Methane Nitrous oxide Ozone Water vapour Halocarbons/Flourine Gasses Human activity increases the amount of these gases in the atmosphere

Over 85% of the world energy supply is carbon-based Carbon Emissions by Sector Hydro, Nuclear, Geothermal, Renewables 14% Fossil Fuels Crude Oil and Natural Gas Liquids 38% Natural Gas 24% Coal 24%

How do humans increase carbon dioxide levels in the atmosphere? Burning fossil fuels releases Carbon stored underground into the atmosphere Deforestation releases carbon stored in trees. Less trees = less CO2 removed from the atmosphere.

Correlation between CO2 and temperature

How do humans increase methane levels in the atmosphere? Increased rice growing Methane is also released when fossil fuels are extracted Increased rubbish in landfill The amount of methane in the atmosphere has increased by two and a half times since the Industrial Revolution. Increased livestock farming

Greenhouse Gas Emissions By Sector

Global Warming vs Climate Change

Paleoclimatology The study of climate change taken on the scale of the entire history of the Earth Natural materials such as rock, trees, corals and ice preserve clues to discovering the climate of the past

Clues to Earth’s Past Climate GLACIERS OCEAN SEDIMENTS CORAL REEFS TREE RINGS PALEOCLIMATOLOGY TREE RINGS ROCK LAYERS POLAR ICE CAPS POLLEN

Natural Factors Causing Global Warming -Greenhouse Effect -Variations in Sun’s Energy Reaching Earth -Changes in ALBEDO of Earth’s surfaces -Slow tilting of Earth’s Axis

Anthropogenic (Man-made) Causes of Global Warming -Burning Fossil Fuels -Increased Automobile Use -Respiration -Mining Activities -Rapid Industrialization

Positive & Negative Feedback Loops of Global Warming

Positive Feedback Examples (SPEEDS) CH4

THAWING OF PERMAFROST

Negative Feedback Example (SLOWS)

Effects of Global Warming Rising Seas/Increased Coastal Flooding Heavier Precipitation/Flooding Increased Pressure on Ground Water Supplies Melting Ice Increased Extreme Weather Events More Severe Droughts Longer/More Damaging Wildfire Seasons Effects of Global Warming Widespread Forest Death More Destructive Hurricanes More Frequent/Intense Heat Waves Costly/Growing Health Impact Plant/Animal Habitat Change Melting Permafrost Disruptions to Food Supply Increased Spread of Disease Coral Reef Destruction Ocean Acidification

**CHINA is currently the top GHG producer Kyoto Protocol (Negotiated in1997) (Enforced in 2005) -International agreement linked to the United Nations Framework Convention on Climate Change (UNFCC) -Industrialized countries would be legally obliged to cut their greenhouse gas emissions 5% on 1990 levels by 2008-2012.- -If participant countries continue with emissions above the targets, then they are required to engage in emissions trading; i.e. buying "credits" from other participant countries who are able to exceed their reduction targets in order to offset.  -Developing countries – including China, India, Brazil and South Africa – would face no restriction on their emissions **CHINA is currently the top GHG producer

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