Dangerous
Climate Change
Sea
Level Rise
Below:
Satellite radar altimetry indicates an average rate of sea level rise globally
of about 3 millimeters per year over the last two decades
Cost
of sea level rise:
•
Loss of land through inundation and
erosion
•
Displacement of people
•
Salt intrusion into freshwater resources
•
Increased flooding due to storm surges
•
Cost of holding back the sea (where
possible)
Summary
1)
Sea level is
rising at an average rate of 3mm/year, with half due to thermal expansion, and
half due to contributions from melting ice
2)
The sea level
rise attributed to melting ice comes from mountain glaciers, the Greenland ice
sheet, and West Antarctic ice sheet
3)
Sea level rise
of an additional meter (3 feet) by the end of the century would directly impact
low lying coastal areas around the world
4)
Estimates of SL
rise must account for changing rates of ocean warming and melting of land ice,
which depend on complicated feedbacks in the climate system
The
Earth Climate System
“95%
certainty that human activities are responsible for most of the warming over
the last half century, largely from greenhouse gas emissions” IPCC, 2013
Below:
Dangerous Climate Change
•
Probability and magnitude of serious
climate impacts increases with increasing CO2 in the atmosphere
•
~550 ppm CO2 scales out to an
additional global surface temperature increase of >3°C by 2100
Above: Sources of United States power
generation (electricity) since 1950
Above:
Worldwide in 2010 about 9 Giga-tons of Carbon (GtC)
were emitted from burning fossil fuels as 33 Giga-tons of CO2 gas.
Source: NOAA
Climate
impacts
Climate
impacts will vary greatly as a result of a region’s
•
Sensitivity:
degree to which a system is affected, either adversely or beneficially
•
Adaptive
capacity: ability of a system to adapt to climate change to moderate
potential damage
•
Vulnerability:
degree to which a system is susceptible to adverse effects of climate change
Above: Monthly global
surface air temperature anomalies in degrees Celsius (relative to long term
average measured from 1978 to 2013 = 0)
Summary