Download 11.2 Human Activity and Climate Change (change in long term

11.2 Human Activity and Climate
Change (change in long term
weather patterns)
Global Warming
An increase in global average temperature
The average global temp has risen 0.74ºC from 1906-2005
Predictions say an increase of 1-2.5ºC in 50 years and 6ºC in
next 100 years
Enhanced Greenhouse Effect
The increased ability of the atm to absorb and emit
thermal energy (because of greenhouse gases)
GWP- Global Warming Potential- describes the
ability of a substance to warm the atm
Greenhouse Gases GWP
Greenhouse Gas
Carbon dioxide
Atm Lifetime
(years)
Source
Global Warming
Potential (GWP)
Variable
Fossil fuels
Deforestation
1
Methane
12
Fossil Fuels
Livestock
Waste
Rice paddies
25
Nitrous oxide
114
Chemical fertilizers
Burning waste/ fossil fuels
Industry
298
CFCs
45
Liquid coolants
Refrigeration
AC
4750-5310
Global Warming 101
National Geographic
Albedo and Climate
Albedo affects the amount of
solar radiation
sea ice melts = lowers
albedo = more radiation =
higher temp
Reading Check
What is the difference between the natural
Greenhouse effect and the enhanced
greenhouse effect?
What does GWP describe?
List 3 greenhouse gases that are released
when fossil fuels are burned
Name a greenhouse gas that does not occur
naturally
What has a higher albedo: sea ice or soil?
Role of science- Understanding
Climate Change
General Circulation Models
(GCMs) are computer
models designed to study
climate
Provide predictions of future
conditions based on multiple
factors
International Cooperation
Intergovernmental Panel on Climate Change
(IPCC) was formed
Investigate human’s contribution to Global
Warming
Experts from 130 countries
Potential Global Impacts of Climate
Change
Main fisheries affected (trade decrease)
Sea level rise
Deforestation (increase forest fire risk)
Water shortage
Disease risk
Increase severity and frequency of storms
Decreasing crop yields
Change in biomes (Canada’s permafrost)
Uncertainty and Decision
Predictions about climate change cannot be
certain
Two extreme scenarios to consider:
1. Climate change will not greatly affect our lives or
our environment
2. Climate change will cause drastic changes in
weather patterns that will greatly affect our lives
and environment
What would be the consequence of not acting?
Strategies for Addressing Climate
Change