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 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

ppm

vSources: 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

Current CO2 Concentration

Pre-industrial CO2 Concentration

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?

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)

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 CO2

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 SoilsMethane released from peat bogs &

oceans?

Desertification of large parts of Earth’s surface

World ecosystems cannot adapt

Positive Feedback: Warming causes further release of greenhouse gases

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?

0

1

2

3

4

5

6

7

Without Postive Feedback With Positive FeedbackIncr

ea

se in

Te

mp

era

ture

(d

eg

ree

s C

els

ius)

Energy demand is rising rapidly

* In agreement with the recommendations from the Royal Academy of EngineersSources: Reference Scenario, IEA (2004) World Energy Outlook; A1T Scenario IEA (2003) Energy to 2050

-

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

Year

En

erg

y D

eman

d (

GW

) Reference Scenario

Fast Economic Growth - A1T

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

"Fast Economic Growth" (A1) Business as Usual Scenario

-

10,000

20,000

30,000

40,000

1990 2000 2010 2020 2030 2040 2050

Ene

rgy

Con

sum

ptio

n (G

W)

-

1

2

3

4

Com

mitt

ed (

CO

2-in

duce

d) T

empe

ratu

re

Ris

e

Low Emissions Energy

Fossil Fuel Energy

Temperature

Dangerous Threshold

Passed

(550ppm)

(2100 CO2 concentration

920ppm)

(CO2 Now: 380ppm)

•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).

“Business as usual” would lead to disaster within a few decades

A expansion in low-carbon energy can stabilise emissions…

…But temperatures may still pass “dangerous” threshold

Source: IEA (2003)…

"Fast Economic Growth" Scenario converting to Low Emissions Energy

-

10,000

20,000

30,000

40,000

1990 2000 2010 2020 2030 2040 2050

Ene

rgy

Con

sum

ptio

n (G

W)

-

1

2

3

4

Com

mitt

ed (

CO

2-in

duce

d)

Tem

pera

ture

Ris

e

Low Emissions Energy

Fossil Fuel Energy

Temperature

Dangerous Threshold Passed

(460ppm)(Stabilisation@ 500ppm)

Sustainable development (lower growth) with complete conversion to low- emissions energy plus additional reductions in consumption

-

10,000

20,000

30,000

40,000

1990 2000 2010 2020 2030 2040 2050

Ene

rgy

Con

sum

ptio

n (G

W)

-

1

2

3

4

Com

mitt

ed (

CO

2-in

duce

d)

Tem

pera

ture

Ris

e

Reduction In Use

Low Emissions Energy

Fossil Fuel Energy

Temperature

Conversion to a zero carbon economy + less total energy used…

Source: IEA (2003) Sustainable Development (SD) scenario with additional reductions.

Danger Avoided!

(Stabilisation @ 400ppm)

'Sustainable' development (lower growth) with Large Exansion in Low-emissions Energy

-

10,000

20,000

30,000

40,000

1990 2000 2010 2020 2030 2040 2050

Ene

rgy

Con

sum

ptio

n (G

W)

-

1

2

3

4

Com

mitt

ed (

CO

2-in

duce

d)

Tem

pera

ture

Ris

e

Low -emissions Energy

Fossil Fuels

Temperature

All countries convert (but some delay)

Source: IEA (2003) Sustainable Development (SD) Scenario.

(450ppm)

Some danger: but most severe impacts avoided.

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

Trains

Electric Cars

Heat Pumps

2030Now

UK CO2 Emissions- 162 Million Tonnes pa

Road transport

20%

Refining etc6%

Other industries

17%

Aviation 5%

Electricity Gene-ration29%

Residen tial-15%

Other8%

Total Energy - 230GW

Electricity17%

Oil for Road

Transport24%

Oil for Aviation

8%

Oil: Industry/

Other 15%

Other3%

Gas Residen tial-20%

Gas Other13%

Total energy = ‘Final Energy’ net of refinery and generation losses2030: Total energy does not include other uses for nuclear heat.

Plus:

Sufficient

Low-Emissions

Energy!!

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 crops

• Fossil fuels with CO2 Sequestration

• Nuclear

• Renewables•Wind•Solar•Hydro•Tidal•Wave•Waste

Electricity

Liquid Fuels or Electricity

Energy Source Main Energy Vector

Energy Crops: Not Enough Cropland

• 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)

Theoretically, how much land would be needed to power the world?

0%

100%

200%

300%

400%

500%

600%

700%

800%

Energy Crops Wind Solar (PV) Nuclear

Pro

po

rtio

n o

f to

tal

wo

rld

cro

pla

nd

2000

2020

2050

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 Crops

• Renewables (12%)

• Fossil fuels with CO2 Sequestration

• Nuclear

Energy Source

Can Only Generate Electricity UK CO2 Emissions-

160m Tonnes pa

Road transport

20%

Refining etc6%

Other industries

17%

Aviation 5%

Electricity Gene-ration29%

Residen tial-15%

Other8%

What about transport,

heating and industry?

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 can be installed in both new and existing houses

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.

Image: Heat Pump theory From Wikimedia Commons

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.

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

If we use non-emitting electricity (e.g. nuclear or micro-generation), CO2 emissions from domestic heating could be reduced by 99%.

Building regulations must ensure that

all new houses have low emissions.

Combining a heat pump with a well -insulated hot water tank allows

energy to be consumed overnight when prices are low.

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

Image: Toyota Prius From Wikimedia Commons

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.

Converting Transport: Long DistanceRail

• 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

Image: Eurostar

Travelling by rail uses much less energy than travelling by car or by plane.

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

EnergyEmissionsIntensity* 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: 90%

*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 CO2 emissions

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).”

ReferencesBudyko, M. I. (1982), The Earth’s Climate: Past and Future, Elsevier, New YorkDefra, (2006) Avoiding Dangerous Climate Change, Cambridge University Press, Cambridge / www.defra.gov.ukDTI (2006) 'Our Energy Challenge', Energy Review Consultation Document / www.dti.gov.ukEPICA (2004) Eight glacial cycles from an Antarctic ice core Nature 429, 623-628IAEA (2000) Annual ReportIEA (2003) Energy to 2050 Scenarios for a Sustainable FutureIEA (2004) World Energy OutlookIEA (2005) Key World Energy StatisticsHarte, 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 BooksLovelock, J (2006) The Revenge of Gaia, Penguin, LondonNuttall, W. J. (2005), Nuclear Renaissance, IOP PublishingPetit J.R., et al. (1999). Climate and Atmospheric History of the Past 420,000 years from the Vostok Ice Core, Antarctica . Nature 399: 429-436Royal Academy of Engineering (2004): The Cost of Generating ElectricityRoyal 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.orgWikisource Images use http://en.wikipedia.org/wiki/GNU_Free_Documentation_LicenseWorld Energy Council (2000) Energy For Tomorrow's World