Download Why Zero Carbon? - Stephen Stretton

Why “Zero Carbon”?
Climate Change and Global Energy Demand
Stephen Stretton
Cambridge Zero Carbon Society
http://camsoc.zerocarbonnow.org
Contents
•
Introduction,
•
Climate Change
•
Global Energy Demand
•
Energy-Emissions model
•
Converting our economy
•
UK Energy Policy 2006
•
What will it take to save the
planet?
•
Next Steps
Introduction: Greenhouse Effect
•
Gases such as Carbon Dioxide (CO2) and Methane absorb reradiated heat in the ‘Greenhouse Effect’.
•
The combustion of fossil fuels such as coal, oil and natural
gas, releases CO2 into the atmosphere, increasing this effect.
Global Concentrations of
Carbon Dioxide
ppmv
400
380
360
340
320
300
280
1959 1969 1979 1989 1999
Sources: CO2 graph shows trend shown without seasonal fluctuation. Data from Mauna Loa Observatory, Hawaii;
Cover Photo © Nasa; Temperature graph from http://www.globalwarmingart.com/
CO2 concentration & temperature
Data from Antarctic ice cores
• CO2 concentration (global) in black
• Reconstructed local temperature in red
• Positive Feedback?
• How much will global temperatures increase for x2 CO2?
Current CO2 Concentration
Pre-industrial CO2 Concentration
Ice Core Data. From Vostok, Antarctica; Main Source: Petit J.R., et al. (1999); c.f. EPICA (2004); Graph: www.globalwarmingart.com
Effects of Climate Change (1)
(Present Day) – Some effects already seen
Oceans damaged
Greenland ice melts (raising sea levels eventually by 7m)
Increases in
Amazon rainforest collapses, releasing CO2
extreme
weather (e.g.
Agricultural yields fall
CO2
hurricanes)
released
Tropical diseases spread
from forests
Methane
World ecosystems cannot adapt
and Soils
released from
peat bogs &
Hundreds of millions at risk from
Global heat
oceans?
hunger & drought
circulation
system
Desertification of large parts of Earth’s surface
collapses?
Positive Feedback: Warming causes further release of greenhouse gases
Source: Adapted from Warren, R (2006)
Effects of Climate Change (2)
• Wholesale
desertification of
Earth possible
within 100 years.
• Large population
centres (China
and India) at risk
Source: Lovelock, J (2006)
How Sensitive Is the Climate?
•
•
•
What is the committed
temperature rise for a
certain level of CO2
concentration?
Climate models suggest
increase in temperature of
1.5-4.5°C associated with
anthropogenic doubling of
CO2
With positive feedback the
range is 1.6-6.0°C
We assume that a doubling of
preindustrial levels causes an
increase in temperature of
4°C
How much would the Earth eventually warm up with a
doubling of preindustrial CO2 concentrations?
Increase in Temperature (degrees
Celsius)
•
7
6
5
4
3
2
1
0
Without Postive Feedback
With Positive Feedback
Energy demand is rising rapidly
Energy Demand (GW)
45,000
40,000
Reference Scenario
35,000
Fast Economic Growth - A1T
30,000
25,000
20,000
15,000
10,000
5,000
1990
2000
2010
2020
2030
2040
2050
Year
Notes
•
All energy (not just electricity) is expressed in terms of GigaWatts (GW)*.
•
1 Gigawatt = 0.75 Million Tonnes of Oil Equivalent per year = 8.8 Terawatt-Hours per Year
•
1 Gigawatt is the usual size of a nuclear power station or large coal power plant
* In agreement with the recommendations from the Royal Academy of Engineers
Sources: Reference Scenario, IEA (2004) World Energy Outlook; A1T Scenario IEA (2003) Energy to 2050
“Business as usual” would lead to
disaster within a few decades
(2100 CO2
concentration
920ppm)
"Fast Economic Growth" (A1) Business as Usual Scenario
Low Emissions Energy
Temperature
30,000
4
3
(CO2 Now:
380ppm)
20,000
2
10,000
1
-
1990
2000
2010
2020
2030
2040
2050
Rise
Dangerous
Threshold
Passed
Fossil Fuel Energy
Committed (CO2-induced) Temperature
Energy Consumption (GW)
40,000
(550ppm)
•
Model committed temperature (the temperature rise expected as a result of emissions up to that point).
•
Note that temperature rises do not include the effect of other greenhouse gases such as methane.
•
For spreadsheet model and discussion of assumptions see website: www.zerocarbon2030.org.
Sources: Sceffer, M et Al. (2006), Defra (2006).
A expansion in low-carbon energy can
stabilise emissions…
…But temperatures may still pass “dangerous” threshold
"Fast Economic Growth" Scenario converting to Low Emissions Energy
40,000
Energy Consumption (GW)
Low Emissions Energy
Dangerous
Threshold
Passed
Fossil Fuel Energy
30,000
Temperature
4
3
20,000
2
10,000
1
-
1990
2000
2010
2020
2030
2040
(Stabilisation
@ 500ppm)
Committed (CO2-induced)
Temperature Rise
(460ppm)
2050
Source: IEA (2003)…
Conversion to a zero carbon economy
+ less total energy used…
Sustainable development (lower growth) with complete conversion to lowemissions energy plus additional reductions in consumption
Danger
Avoided!
Reduction In Use
Low Emissions Energy
30,000
Fossil Fuel Energy
Temperature
4
3
(Stabilisation
@ 400ppm)
20,000
2
10,000
1
-
1990
2000
2010
2020
2030
2040
Committed (CO2-induced)
Temperature Rise
Energy Consumption (GW)
40,000
2050
Source: IEA (2003) Sustainable Development (SD) scenario with additional reductions.
All countries convert (but some delay)
4
Low -emissions Energy
Fossil Fuels
30,000
(450ppm)
3
Temperature
20,000
2
10,000
1
-
1990
2000
2010
2020
2030
2040
Temperature Rise
40,000
Committed (CO 2 -induced)
Energy Consumption (GW)
'Sustainable' development (lower growth) with Large Exansion in Low-emissions
Energy
2050
Some danger: but most severe impacts avoided.
Source: IEA (2003) Sustainable Development (SD) Scenario.
CO2 Emissions by Geographical Region
Source: IEA (2003) - Energy Related emissions only
How can we save the planet
• International Agreement on climate is difficult
(‘tragedy of the commons’).
• Massive cuts in emissions (80-90%) are
required (Kyoto not sufficient).
• Need a country or countries to take the lead
in converting to a zero carbon economy.
• Other countries may in fact act
simultaneously.
A 90% Reduction in
CO2 emissions by 2030 –
What will it take?
1. Immediate Reductions in Energy
Consumption
2. Large Increase in Sustainable Energy
Supply
3. Conversion of economy to use low
emissions electricity or hydrogen
Now
2030
Trains
Total Energy 230GW
Other
3%
Electricity
17%
Gas
Residen
tial-20%
Plus:
Oil for
Road
Transport
24%
Gas Other
13%
Oil:
Industry/
Other 15%
Electric Cars
Oil for
Aviation
8%
Low-Emissions
UK CO2 Emissions162 Million Tonnes pa
Other
8%
Residen
tial-15%
Electricity
Generation
29%
Sufficient
Energy!!
Heat Pumps
Other
industries
17%
Refining
Aviation
etc
5%
6%
Road
transport
20%
Total energy = ‘Final Energy’ net of refinery and generation losses
2030: Total energy does not include other uses for nuclear heat.
How do we convert our economy to use
low emissions electricity?
Stephen Stretton
Cambridge Zero Carbon Society
http://camsoc.zerocarbonnow.org
The Potential Solutions
Energy Source
•
Energy crops
•
Fossil fuels with CO2 Sequestration
•
Nuclear
•
Renewables
•Wind
•Solar
•Hydro
•Tidal
•Wave
•Waste
Main Energy Vector
Liquid Fuels or Electricity
Electricity
Energy Crops: Not Enough Cropland
Theoretically, how much land would be needed to power the world?
Proportion of total world cropland
800%
700%
2000
2020
600%
2050
500%
400%
300%
200%
100%
0%
Energy Crops
Wind
Solar (PV)
Nuclear
• Available cropland will diminish with global warming and population
growth.
• Fertile land is needed for climate regulation and growing food.
• Energy Crops are NOT green!!!
Source: Estimated from Socolow (2006) and IEA (2003)
Comparing Emissions
Fossil Fuel Energy
Low Emissions Energy
•
Also: Energy Crops, Waste Incineration, Tidal & Wave
•
Fossil Fuels with CO2 sequestration.
Problem: Electricity is not always suitable
for transport, heating & industry
Energy Source
•
Energy Crops
•
Renewables (12%)
•
Fossil fuels with CO2
Sequestration
•
Nuclear
Can Only
Generate
Electricity
UK CO2 Emissions160m Tonnes pa
Other
8%
What about
transport,
heating and
industry?
Residen
tial-15%
Electricity
Generation
29%
Other
industries
17%
Refining
Aviation
etc
5%
6%
Road
transport
20%
Heating, Transport and Industry
Domestic heating
(currently mostly gas)
Transport
(currently oil)
Industry
(coal, oil & gas)
How do we
convert to low
emissions
electricity?
Converting Domestic Heating
Heat pumps
• Move heat from a low temperature heat
source (such as the ground outside) and
transfer it to a high temperature heat sink.
• Powered by electricity (from nuclear or
renewables).
• Uses up to 80% less energy.
• Using pump to heat a domestic water tank
can smooth demand & store energy.
A heat pump uses electricity
to move heat from outside to
inside a home. It works on
the same principle as a
refrigerator reversed.
Heat pumps use 50-80% less
energy than gas boilers.
Heat pumps can be installed in both new and existing houses
Image: Heat Pump theory From Wikimedia
Converting Domestic Heating (2)
The Zero-Emissions House
Ground source heat pumps
+ Better house insulation
+ Underground air circulation
+ In/Out heat exchanger
= 90% reduction in energy consumption
Combining a heat pump with a well insulated hot water tank allows
energy to be consumed overnight
when prices are low.
If we use non-emitting electricity (e.g. nuclear or microgeneration), CO2 emissions from domestic heating could be
reduced by 99%.
Building regulations must ensure that
all new houses have low emissions.
Converting Transport: Short distance
Electric Cars
•
Technologies developing quickly,
following success of Toyota Prius
•
Full conversion possible by 2030
Reductions in car use
•
Charge for road congestion
•
Health benefits of walking and
cycling, especially for children
•
Better urban planning & public
transport
Electric cars store energy in batteries
when recharged overnight (when
electricity prices are low).
Hydrogen fuel cell technology developing
and may be in use by 2030. Hydrogen
can be produced using next-generation
nuclear power stations.
Image: Toyota Prius From Wikimedia Commons
Converting Transport: Long Distance
Rail
•
Improve network
•
Build new freight lines
•
Upgrade urban transit systems
(Crossrail)
•
Reduce ticket prices
Aviation
•
Tax aviation more heavily
(noise, CO2, congestion)
•
Ban night flights
Travelling by rail uses much less energy
than travelling by car or by plane.
Image: Eurostar
British Energy Policy 2006
• Background: DTI Energy Review
• Main Goals:
– CO2 Reduction
– Security of Supply
– Economic Efficiency
• Planning?
• Economic Instruments
– Carbon Taxes
– Price Guarantees
Energy Supply Vision 2030
Energy
Emissions
Intensity*
Total Emissions
(GW)
(t C/ GW)
(Mt CO2 / year)
2005
230
162
2030: Reductions in Use
70
Renewables & Nuclear**
125
0.04
4.84
Coal-Gas with (partial) Sequestration#
20
0.13
2.63
Oil ##
15
0.55
8.21
Total
160
0.26
15.7
Reduction in CO2 Emissions:
*Does not include excess heat used in industry and homes or desalination
# Using gas turbines with CO2 Sequestration (85% reduction in CO2 eliminated relative to gas alone).
## For Aviation, Heavy Industry, Road Freight etc Also includes other unavoidable CO 2 emissions
90%
Objectives
1. “We must immediately make substantial lifestyle changes and efficiency
improvements aimed at using less energy, particularly in regard to road
and air travel. “
2. “We must construct sufficient low-emissions generation (renewable/
nuclear electricity) for all our energy needs. We must also significantly
increase research into renewable energy and energy efficiency.”
3. “We must get ready to transform domestic heating, transport and industry
to use and store clean, low-cost electricity instead of burning fossil fuels
(e.g. with electric cars). Any new homes must be constructed on an
ecologically sound, zero-emissions basis (including heat pumps for
domestic hot-water tanks).”
References
Budyko, M. I. (1982), The Earth’s Climate: Past and Future, Elsevier, New York
Defra, (2006) Avoiding Dangerous Climate Change, Cambridge University Press, Cambridge / www.defra.gov.uk
DTI (2006) 'Our Energy Challenge', Energy Review Consultation Document / www.dti.gov.uk
EPICA (2004) Eight glacial cycles from an Antarctic ice core Nature 429, 623-628
IAEA (2000) Annual Report
IEA (2003) Energy to 2050 Scenarios for a Sustainable Future
IEA (2004) World Energy Outlook
IEA (2005) Key World Energy Statistics
Harte, J and Torn M. (2006) Missing feedbacks, asymmetric uncertainties and the underestimation of future warming
Geophysical Research Letters, Vol 33, L10703, 26th May 2006 http://www.agu.org/journals/gl/gl0610/2005GL025540/
Hoyle, F (2006) The Last Generation, Eden Project Books
Lovelock, J (2006) The Revenge of Gaia, Penguin, London
Nuttall, W. J. (2005), Nuclear Renaissance, IOP Publishing
Petit J.R., et al. (1999). Climate and Atmospheric History of the Past 420,000 years from the Vostok Ice Core, Antarctica. Nature
399: 429-436
Royal Academy of Engineering (2004): The Cost of Generating Electricity
Royal Commission on Environmental Pollution (2000) Energy - The Changing Climate
Sceffer, M et Al. (2006) Positive Feedback between global warming and atmospheric CO2 concentration inferred from past
climate change Geophysical Research Letters, Vol 33, L10702, 26th May http://www.agu.org/journals/gl/gl0610/2005GL025044/
Socolow, R. (2006) et al.: Stabilization Wedges: An elaboration of the concept in Defra (2006)
Warren, R (2006): Impacts of Global Climate Change at different Annual Mean Global Temperature Increases in Defra (2006)
Wikipedia – www.wikipedia.org and Wikimedia - commons.wikimedia.org
Wikisource Images use http://en.wikipedia.org/wiki/GNU_Free_Documentation_License
World Energy Council (2000) Energy For Tomorrow's World