climate change: simple, serious, solvable
DESCRIPTION
Climate Change: Simple, Serious, Solvable. Scott Denning Director of Education, CMMAP Atmospheric Science, CSU. Email [email protected] for a copy of this presentation. Common Myths about Climate Be skeptical … be very skeptical !. Climate is complicated … have to ask experts - PowerPoint PPT PresentationTRANSCRIPT
Email [email protected] for a copy of this presentation
Climate Change:Simple, Serious,
Solvable
Scott DenningDirector of Education, CMMAP
Atmospheric Science, CSU
Common Myths about Climate
Be skeptical … be very skeptical !• Climate is complicated … have to ask experts• Concern about global warming is based on
recent temperature trends– “9 of the 10 hottest years on record …”– If somebody could find some other cause for
recent warming, we could quit worrying• Global warming is a theory based on
complicated computer models• If we stop burning coal, we’ll freeze in the
dark!
Weather vs Climate
what’s the difference?• If you don’t like the weather:– Wait five minutes!
• If you don’t like the climate:– Move!
Location! Location! Location!• Depends on where you live:
– Latitude!– Altitude (mountains vs valley)– What’s upwind (ocean vs land)
• Changes very slowly• Very predictable• We can predict that Miami is warmer
than Minneapolis for precisely the same reasons that we can predict a warmer future!
Climate is Place
Ever Wonder Why?
• Day is warmer than night• Summer is warmer than winter• Miami is warmer than Minneapolis
Heat Budgets
Dancing Molecules and Heat Rays!
• Nearly all of the air is made of oxygen (O2) and nitrogen (N2) in which two atoms of the same element share electrons
• Infrared (heat) energy radiated up from the surface can be absorbed by these molecules, but not very well
N N
O O
Diatomic molecules can vibrate back and forth like balls on a spring, but the ends are identical
Dancing Molecules and Heat Rays!
• Carbon dioxide (CO2) and water vapor (H2O) are different!
• They have many more ways to vibrate and rotate, so they are very good at absorbing and emitting infrared (heat) radiation
Molecules that have many ways to wiggle are called “Greenhouse” molecules
O OC
H H
O
Absorption spectrum of CO2 was measured by John Tyndall in 1863
Common Sense• Doubling CO2
would add 4 watts to every square meter of the surface of the Earth, 24/7
• Doing that would make the surface warmer
• This was known before light bulbs were invented!
4 Watts
John Tyndall, January 1863
1 m
1 m
Common Myth #1“People are worried about climate change
because it’s been getting warmer lately”
WRONG! We’re concerned because we know that when we add energy to things, they warm up
• Land vs ocean!• North vs South
• Global mean warming of 2º to 5º C
• North American warming of 3º to 6º C= 5º to 11º F
• Arctic warming of 8º to 14º F
LowEmissions
HighEmissions
ModerateEmissions
Rainfall? Agriculture? Water supply? Ski industry?Mass immigration?
How much warmer?
Where is it 10°F Warmer
Denver Amarillo
Grand Junction Tucson
Illinois MississippiWater? Crops?
Real Estate? Health?
“on average?”
2 2 = 4 billion tons go out
Ocean Land Plants and soils (net)
Fossil FuelBurning
+
8
800billion tons carbon
4billion tons go in
ATMOSPHERE
billion tons added every year
CO2 “Budget” of the World
Extra heat comes from the water, not the faucet!
Shanghai, China 1990
Shanghai, China 2012
• If China and India industrialize with coal, CO2 will rise to 5x preindustrial
• Extra CO2 will last for millennia after coal is gone
The heck with Polar Bears … what would that do to farmers?
CO
2 (pp
m)
GtC
/yr
War
min
g (C
elsi
us)
CO2
warming
year
you arehere
Common Myth #2“When we reduce or stop burning fossil fuel,
CO2 will go away and things will go back to normal”
emissions
A Region On the EdgeMuch of the region already receives only marginal precipitation
Just enough snow to support forests and reservoirs
Just enough irrigation water to support farming
Just enough water to support 5.1 million people
Insect Pests
Western US
Wildfires
Irrigated Agriculture
Real Estate Development
We Know for Sure• CO2 molecules absorb & re-emit
thermal radiation (John Tyndall, 1863)• Each doubling of the number of CO2
molecules would add 4 W m-2 to the Earth 24/7 (Svante Arrhenius, 1896)
• If China and India industrialize with coal, CO2 will approach 400% preindustrial by 2100 (so 8 Watts, not 4, on each sq m)
• Additional CO2 will continue adding heat to Earth for thousands of years
What We’re Not So Sure
About• When and precisely how the
climate will change, especially locally
• The economic, political, and social consequences of these changes
• What to do about all of this
The Worst Myth of All
“The sky is falling!”Be skeptical … be very skeptical !
• Without the subsidy of cheap fossil energy, civilization will crumble
• People will freeze in the dark!• We’ll starve!
Billions of Tons Carbon Emitted per Year
Historical emissions
0
8
16
1950 2000 2050 2100
Historical Emissions
1.6
Interim Goal
Billions of Tons Carbon Emitted per Year
Current p
ath = “r
amp”
Historical emissions Flat path
Stabilization Triangle
0
8
16
1950 2000 2050 2100
The “Stabilization Triangle”
1.6
Billions of Tons Carbon Emitted per Year
Current p
ath = “r
amp”
Historical emissions Flat path
0
8
16
1950 2000 2050 2100
16 GtC/y
Eight “wedges”
Goal: In 50 years, sameglobal emissions as today
“Stabilization Wedges”
http://www.princeton.edu/wedges/
What is a “Wedge”?A “wedge” is a strategy to reduce carbon emissions that grows in 50 years from zero to 1.0 GtC/yr. The strategy has already been commercialized at scale somewhere.
1 GtC/yr
50 years
Total = 25 Gigatons carbon
Cumulatively, a wedge redirects the flow of 25 GtC in its first 50 years. This is 2.5 trillion dollars at $100/tC.
A “solution” to the CO2 problem should provide at least one wedge.
Energy Efficiency & Conservation (4)
CO2 Capture & Storage (3)
Stabilization Triangle
Renewable Fuels& Electricity (4)
Forest and Soil Storage (2)
Fuel Switching(1)
Nuclear Fission (1)
2007 20578 GtC/y
16 GtC/y
TriangleStabilization
Fifteen Wedges in 4 Categories
http://www.princeton.edu/wedges/
Double the fuel efficiency of the world’s cars or halve miles traveled
Produce today’s electric capacity with double today’s efficiency
Use best efficiency practices in all residential and commercial buildings
Replacing all the world’s incandescent bulbs with CFL’s would provide 1/4 of one wedge
Efficiency
There are about 600 million cars today, with 2 billion projected for 2061
Average coal plant efficiency is 32% today
Photos courtesy of Ford Motor Co., DOE, EPA
Substitute 1400 natural gas electric plants for an equal number of coal-fired facilities
A wedge requires an amount of natural gas equal to that used for all purposes today
Fuel Switching
Photo by J.C. Willett (U.S. Geological Survey).
Implement CCS at
• 800 GW coal electric plants or• 1600 GW natural gas electric
plants or• 180 coal synfuels plants or• 10 times today’s capacity of
hydrogen plants
Graphic courtesy of Alberta Geological Survey
Carbon Capture & Storage
There are currently three storage projects that each inject 1 million tons of CO2 per year – by 2061 we’d need 3500.
Wind Electricity
Install 1 million 2 MW windmills to replace coal-based electricity, ORUse 2 million windmills to produce hydrogen fuel
Photo courtesy of DOE
A wedge worth of wind electricity will require increasing current capacity by a factor of 30
Solar Electricity
Photos courtesy of DOE Photovoltaics Program
Install 20,000 square kilometers for dedicated use by 2054
A wedge of solar electricity would mean increasing current capacity 700 times
Solutions• To provide a decent standard of living
for billions of people on Earth• We must be able to generate huge
amounts of energy without releasing CO2
• This is definitely do-able (as an engineering task) …
• but expensive and politically difficult• Can’t do it by “tinkering around the
edges”• Requires profound change to energy
and economics
Imagine it’s 1800, and you’re in charge …
Somebody presents you with a grand idea for transforming the world economy: Dig 8 billion tons of carbon out of the
ground every year Build a system of pipelines, supertankers,
railroads, highways, and trucks to deliver it to every street corner on the planet
Build millions of cars every year, and millions of miles of roads to drive them on
Generate and pipe enough electricity to every house to power lights & stereos & plasma TVs… “and here’s the itemized bill …”
Choose Your Future• Some people think:
– “Our modern lifestyle is only possible because of the subsidy of cheap fossil fuel. When we stop burning coal we’ll freeze in the dark!”
• I prefer:– “Our well-being depends on
creativity and hard work. Before we run out of oil, we’ll invent energy technologies for the 21st Century.
–Our future is bright.”