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1500F: Lecture 17: November 14th: Climate Change
o Share recent updates on climate change science
o Challenge common ‘conspiracy theories’
o Identify key challenges and achievements in the governance of climate
o Discuss differentiated impacts of climate change around the world –
including conflict over water resources
Where can we look for climate change science?
Intergovernmental panel on climate change
Hundreds of experts from around the world
Synthesizes recent publications on climate change
Only includes peer-reviewed science – and IPCC reports themselves are
extensively peer reviewed
The summary for policy makers is negotiated and approved line-by-line by
IPCC Assessment Reports
I: the physical science basis
II: impacts, adaptation and vulnerability
III: Mitigation of climate change
What can cause climate change?
1. Change in amount of solar radiation reaching Earth
2. Change in amount of solar radiation reflected
3. Change in amount of radiation re-emitted to space
1. change in incoming solar radiation
a. change in Earth’s orbit or the Sun itself
b. past ice ages linked to changes in orbit
c. less summer sunshine in north means snow accumulates
d. next drop n northern summer sunshine: 30, 000 years
2. change in amount of solar radiation reflected
a. albedo: the proportion of solar energy a surface reflects
b. light surfaces reflect more; dark ones reflect less
c. what surfaces on the Earth have a high albedo?
iii. Open water
v. Ash fault
vi. Ploughed land with no vegetation growing yet
3. Change in radiation emitted to space
a. Changes can have spill over effects. How?
b. If greenhouse gas concentrations increase…
c. If volcanic activity creates an ash cloud….