what will it take to prevent dangerous climate change? an investigation of low- carbon energy...
TRANSCRIPT
What will it take to prevent dangerous climate change?
An Investigation of Low-Carbon Energy Sources including Nuclear Energy
Stephen Stretton
Gonville and Caius College,Cambridge15th June
Contents
• Introduction: Climate change and world energy consumption
• Potential zero carbon energy sources
• Using electricity for heating and transport
• Energy and Climate Scenarios
• UK Energy Policy
• Conclusion
*Very low CO2 emissions (less than 10% of fossil fuel equivalent)Cover Photo: NASA
Introduction: Greenhouse Effect• Gases such as Carbon Dioxide (CO2)
and methane absorb re-radiated 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
280
300
320
340
360
380
400
1959 1969 1979 1989 1999
ppmv
Strong correlation between carbon dioxide concentration and temperature
Current CO2 Concentration
Pre-industrial CO2 Concentration
• Data from Antarctic ice coresCO2 concentration in blackReconstructed temperature in red
Effects of Climate Change
Source: Adapted from Warren, R (2006)
(Present Day) – Some effects already seen
Oceans damaged
Greenland ice melts (raising sea levels eventually by 7m)
Amazon rainforest collapses, releasing carbon dioxide
Increases in extreme
weather (e.g. hurricanes)
Agricultural yields fall
Tropical diseases spread
Global heat circulation
system collapses?
Hundreds of millions at risk from hunger & drought
CO2 released
from forests and
Soils
Methane released from peat
bogs
Desertification of large parts of Earth’s surface
World ecosystems cannot adapt
Positive Feedback: Warming causes further release of greenhouse gases
Forest Fire: Both Causes AND Results from Global Warming?
Forest Fire in Australia
Effects of Climate Change
• Wholesale desertification of Earth possible within 100 years.
• Large population centres (China and India) at risk
• Water Wars?
Source: Lovelock, J (2006)
How Can We Save Planet Earth?• International Agreement on
climate is difficult
• Climate change demands huge cuts in emissions (Kyoto not sufficient)
• Politically difficulties?
• At present the required cuts in emissions seem like an almost impossible task – but nobody has tried!
• We need a country or countries to take the lead.
‘Environmental Relativism’ Misses the Bigger Picture
Energy• Our use of energy generates almost all
our greenhouse gas emissions
• Energy is used in the whole economy.
• Stop using energy and you do not have an economy
• But to generate that energy takes only a small part of our efforts.
• We can redirect these efforts
• Investment in zero emissions generation can be economically and strategically beneficial.
Energy demand is rising rapidly
Source: Reference Scenario, IEA World Energy Outlook (2004)“Sustainable Level” purely illustrative (depends on assumptions on emissions intensity and climate change)
-
5,000
10,000
15,000
20,000
25,000
1990 2000 2010 2020 2030
Year
Energy Demand (GW)Sustainable
Level?
Energy consumption per person
Source: IEA (2003)Sustainable Level Purely Illustrative
Energy Use and CO2 Emission Per Person
-
5
10
15
20
25
Canada Russia Europe Japan US WORLD Brazil China India Australia
PrimaryEnergy (kW)per person
CO2Emissions(tonnes/year)per person
Sustainable
Level?
Energy & Climate Scenarios
• Assume 1 Gt of CO2 increases atmospheric concentrations by 0.08ppm.
• Assume IEA future energy demand scenarios A1T and ‘SD’.
• Model committed temperature (the inevitable warming due to CO2 already emitted), rather than actual temperature at a certain date (note difference with IPCC).
• IPCC simulations do not account for positive feedback – problem is more serious than we thought.
• In these models we assume a climate sensitivity parameter of 4. A doubling of pre-industrial CO2 concentrations would lead to a final rise in temperature of 4˚C. This is close to the median of recent estimates of this parameter.
• Assume dangerous climate change (collapse of ecosystems, carbon sinks become sources) begins at 2˚C.
“Business as usual” would lead to disaster within a few decades
Source: IEA (2003), augmented with this author’s calculations
"Fast Economic Growth" (A1) Scenario
-
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
1990 2000 2010 2020 2030 2040 2050
Energy Consumption (GW)
-
0.50
1.00
1.50
2.00
2.50
3.00
3.50
Committed Temperature Rise
Low Emissions Energy
Fossil Fuel Energy
Temperature
Dangerous Threshold
Passed
A expansion in low-carbon energy can stabilise emissions…
…But still temperatures may still pass “dangerous” threshold
Source: IEA (2003), augmented with this author’s scenario and calculations
"Fast Economic Growth" Scenario converting to Nuclear Energy
-
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
1990 2000 2010 2020 2030 2040 2050
Energy Consumption (GW)
-
0.50
1.00
1.50
2.00
2.50
3.00
3.50
Committed Temperature Rise
Low Emissions Energy
Fossil Fuel Energy
Temperature
Dangerous Threshold Passed
A large expansion in low-emissions capacity + less total energy used…
Source: IEA (2003), augmented with this author’s scenario and calculations
'Sustainable' Development (lower growth) with Nuclear Energy plus additional reductions in consumption
-
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
45,000
1990 2000 2010 2020 2030 2040 2050
Energy Consumption (GW)
-
0.50
1.00
1.50
2.00
2.50
3.00
3.50
Committed Temperature Rise
Reduction In Use
Low Emissions Energy
Fossil Fuel Energy
Temperature
Danger Avoided!
But can it be done??
Major Low-Emissions Energy Sources
• Biomass (energy crops)
• Fossil fuels with CO2 Sequestration
• Wind
• Solar
• Tidal
• Wave
• Nuclear
Electricity
Liquid Fuels or Electricity
Energy Source Main Energy Vector
Biomass: Land Area Issue?
• Available cropland will diminish with global warming and population growth.
Source: Estimated from Socolow (2006) and IEA (2003)
Theoretically, how much land would be needed to power the world?
0%
100%
200%
300%
400%
500%
600%
700%
800%
Biomass* Wind Solar (PV) Nuclear
Proportion of total world cropland
2000
2020
2050
Fossil fuels with CO2 Sequestration
• Fossil fuels burnt and CO2 then buried in underground rock formation
• Potential solution for areas with large amounts of oil & natural gas (Middle East?)
Image Courtesy of the Energy Council of the Netherlands
Solar energy
• Photovoltaic Cells
• Appropriate for equatorial regions
• Good for those regions without a centralised grid
WindGovernment target: wind to generate 20% of UK electricity by 2020
= Approximately 5% of total UK energy
Source: Defra/DTI
• Because of intermittency, for any higher proportion, we need storage technologies.
• However, storage technologies are only environmentally friendly when most of electricity is zero-carbon emitting… (catch-22?)
Nuclear
Image of AP 1000 Reactor © Westinghouse
Modern Nuclear Reactors*
• ‘Passive’ safety
• Quick construction
• Compact
• Constructors take price risk
• Inexpensive decommissioning
• Reduced fuel consumption
• Much less waste
• Price competitive with gas
*(e.g. Westinghouse AP1000European PWR, Canadian ACR)
Cost of Generating Electricity
Source: Royal Academy of Engineering (2004)
Emissions from Electricity Generation
Major Low-Emissions Energy Sources
• Biomass (energy crops)
• Fossil fuels with CO2 Sequestration
• Wind
• Solar
• Tidal
• Wave
• Nuclear
Generate ElectricityIntermittency & Inflexibility?
Liquid Fuels or Electricity
Energy Source Main Energy Vector
(Land Area)
BUT electricity is only a part of total energy use (at present)
Source: DTI
Electricity generates only one third of CO2 emissions
Source: Defra
Can other sectors be converted to use carbon-free electricity?
Domestic heating (currently gas)
Transport (currently oil)
Industry (oil and gas)
Use (and Store?) Carbon-Free Electricity?
Domestic HeatingFor New Homes:
• Better house insulation
• Heat Pumps
• Underground air circulation
• Air-out / Air-in heat exchanger
• = Huge (~97%*) reduction in Energy Use
*Estimate for Illustrative Purposes
• If we use non-emitting energy, CO2 emissions from heating would be virtually zero
• Existing homes can also be converted: savings would still be very substantial
Industry
• Industry requires a secure, reliable and cheap energy source.
• Nuclear electricity is low cost (especially at night) and provides a convenient alternative to gas, hedging the price risk of energy.
• Presently, gas prices and electricity are highly correlated.
Transport: Short distance
• Electric cars can be plugged in overnight, using spare capacity. Battery technologies are developing rapidly and range is increasing.
• ‘Plug-in hybrid’ are also promising. Electricity used for short distances, advanced bio fuels(?) for longer distances.
• Long waiting lists for hybrid cars e.g. Toyota Prius.
• Car companies currently developing further models.
Transport: Long Distance• Build a high speed rail network!
• Build new freight rail lines.
• Upgrade urban transit systems (Crossrail).
• THEN reduce prices!
• Tax Aviation more heavily (noise, CO2, congestion)
• Encourage British tourism!
Electricity for
Industry
Aviation (??)
Electricity for Road Transport
Electricity for
Domestic Heating
Heavy Industry / Construc-
tionRoad Freight
Other Sectors
Electricity - Other
What would a zero-carbon economy look like?
High emissions regions already have a nuclear industry
Source: IEA (2005)
A Solution For Britain
• Build 100-200GW of nuclear capacity over the next 20 years.
• Aim to generate 90% of total energy requirements in 2030 through nuclear power.
• Use American AP 1000, European EPR or Canadian CANDU reactor, or all three.
The French Experience• France in 1970s – 1990s converted 80% of electricity to Nuclear.
• Realised economies of scale by using one design.
• Used a single type of reactor, often with duplicate units on same site.
• France now has the lowest electricity prices in Europe.
• Electricity is a major export good.
• Britain needs a similar building program – but even more ambitious (3x bigger).
• We should convert all energy to nuclear (including using electricity in heating and road transport).
Constraints on a Nuclear Expansion?• Uranium Reserves? - Sufficient for an expansion in the nuclear
industry. Fuel costs are only a small part of cost of nuclear – rises in Uranium price will lead to more reserves becoming economic. Fast breeder reactors can take over if Uranium becomes scarce.
• Public acceptability of nuclear will increase if it is seen as a solution to the problem of climate change.
• Some nuclear reactors (first few) can be based at existing sites. New reactors (e.g. AP1000) much smaller and more than one reactor can be built in each place.
• However, there must be a ‘bank’ developed of about 50 suitable nuclear sites (with planning permission) across the UK (not threatened by flooding or coastal erosion due to sea-level rises).
• Only constraint for the UK is SKILLS. We need a massive program to train at least 50,000 (and probably more) new nuclear engineers over the next few years.
Summary• To prevent ‘dangerous’ climate change we need to act
rapidly.
• We must invest in all low-emissions technologies.
• Nuclear is large to generate a large part of our total energy (not just the small part that is currently electricity).
• Cars and domestic heating can be converted to run off electricity. More freight can be transported by rail.
• Cuts in consumption (e.g. aviation, long distance car use) are also necessary.
• “Electricity is the nervous system of civilisation” (Lovelock).
ReferencesComby, B. (2006), Environmentalists for Nuclear Energy, Canadian Edition
Defra, (2006) Avoiding Dangerous Climate Change, Cambridge University Press, Cambridge and www.defra.gov.uk
DTI (2006) 'Our Energy Challenge', Energy Review Consultation Document and www.dti.gov.uk
IAEA (2000) Annual Report
IEA (2003) ENERGY TO 2050 Scenarios for a Sustainable Future
IEA (2005) Key World Energy Statistics
Lovelock, J (2006) The Revenge of Gaia, Penguin, London
Mackay, D. (2006,Unpublished) Online notes on energy at http://www.inference.phy.cam.ac.uk/mackay
Nuttall, W. J. (2005), Nuclear Renaissance, IOP Publishing
Royal Academy of Engineering (2004): The Cost of Generating Electricity
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)
World Energy Council (2000) Energy For Tomorrow's World
Nuclear Energy: for the Future of Earth
Comments to:
Stephen Stretton
www.zerocarbonnow.org