1. Natural and Unnatural Greenhouse Effect
SNC2D1
Mr. Findlay

2. Did You Know? With dry ice and a plane, you can create a rainstorm.
Here’s how cloud seeding, or making rain artificially works:
A plane drops crushed dry ice into a cloud;
The dry ice attracts water droplets and ice crystals;
These crystals get bigger and heavier until they fall to Earth as rain.
Not everyone agrees on how useful and fair it is to use this process.

3. Natural Greenhouse Effect
Earth depends on energy coming from the Sun.
About half of the energy received is absorbed and re-radiated as infrared heat.
90% is then absorbed by Greenhouse Gases and radiated out in all directions.
The surface maintains an average temperature of 15oC due to this effect.
Without these gases, the Earth would be 33o cooler with an average temperature of -18oC.

4. Natural Greenhouse Effect

5. Why are they called greenhouse gases?
Act like the glass of a greenhouse.
Visible light passes by but infrared light is reflected.

6. What are the greenhouse gases?
Most abundant
Traps heat and radiates some of it back to Earth
Water Vapour (H2O)
Minor component of the atmosphere but very important
Humans have increased the concentration by 33% since the Industrial Revolution
Carbon Dioxide (CO2)
Powerful greenhouse gas produced by agriculture
Sources: fertilizers, fossil fuel combustion, nitric acid production, and biomass burning.
Nitrous Oxides (N2O)

7. What are the greenhouse gases?
Hydrocarbon produced through natural processes and human activities
Cows are a major producer of methane through the release of gas and wastes
Methane (CH4)
Major concern in the troposphere
Acts as a ceiling, blocking or trapping heat closer to the Earth
Ozone (O3)
Synthetic compounds developed for industrial purposes
Contribute to the destruction of the ozone layer in the stratosphere
Chlorofluorocarbons (CFC)

8. Unnatural Greenhouse Effect
Discovery of petroleum based fuels on Earth and the knowledge to burn them has contributed to massive amounts of carbon dioxide being released into the atmosphere.
Increasing greenhouse gases through human activities is called the anthropogenic greenhouse effect.

9. Anthropogenic Greenhouse Effect

10. Greenhouse Gas Production
Rank
Country
Annual CO2 Emissions (thousands)
Percentage of total emissions
Country’s Population (thousands)
Emissions per Capita (tonnes) 1
China
21.5%
4.58 2
United States
20.2%
18.70 3
Russia
5.5%
11.03 4
India
5.3%
1.29 5
Japan
4.6%
10.14 6
Germany
2.8%
82 002
9.82 7
United Kingdom
2.0%
61 634
9.22 8
Canada
1.9%
33 806
16.11 9
South Korea
1.7%
48 333
9.83 10
Italy
1.6%
60 114
7.89

11. Evidence of Climate Change