Transcript Powerpoint file for Chapter 1 (Introduction)

Energy and the New Reality, Volume 1:
Energy Efficiency and the
Demand for Energy Services
Chapter 1: Prospective Climatic Change,
Impacts and Constraints
L. D. Danny Harvey
[email protected]
Publisher: Earthscan, UK
Homepage: www.earthscan.co.uk/?tabid=101807
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Two strong reasons for becoming
more efficient in the use of energy:
• Global Warming (discussed this hour)
• Peak oil (dealt with in transportation PS)
Heating trapping (“forcing”) due to variations in greenhouse gas (GHG)
concentrations over the past 45 million years (Ma), as inferred from
various lines of geological evidence, compared with the range of GHG
forcing projected by 2100 under business as usual scenarios. The last
time the forcing or heat trapping was a high as is projected for 2100,
there was no ice anywhere on this planet.
Controls over the Earth’s Climate
• The Earth’s climate is governed by the balance
between absorption of solar radiation and
emission of infrared radiation
• Any imposed alteration in either term is called a
radiative forcing
• Following a radiative forcing, the temperatures
of the Earth’s surface and atmosphere will
naturally adjust to bring solar absorption and
infrared emission back into balance
The “greenhouse” effect
• Refers to the partial absorption by certain gases
in the atmosphere of infrared radiation emitted
by the Earth’s surface
• Because absorption of any radiation (whether
solar or infrared) has a warming effect, this
makes the climate warmer than it would be
otherwise (by about 33ºC for the naturallyoccurring greenhouse effect)
• The key GHGs are: water vapour, CO2, ozone
(O3), methane (CH4) and nitrous oxide (N2O)
Human Impacts on Climate
• Humans have directly emitted and increased the
concentrations of CO2, CH4, N2O and various
artificial GHGs (CFCs, HCFCs, HFCs, SF6), and
pollutant emissions (NOx, CO and hydrocarbons)
have lead to an increase in ground-level ozone
• This in turn has caused a radiative forcing so far
of about 2.5-3.5 W/m2
• If CO2 alone were to double, the radiative forcing
would be about 3.75 W/m2
• Thus, the GHG increases so far are already
equivalent to a 70-90% increase in CO2
400
5000
X
Present
4500
350
300
4000
CO2
3500
250
3000
200
2500
2000
150
100
Present X
CH4
1000
50
0
400000
1500
500
0
300000
200000
100000
Years Before Present
0
Methane Concentration (ppbv)
Carbon Dioxide Concentration (ppmv)
Figure 1.1 Variation in CO2 and CH4 Concentration
The trapping of radiation initiates a series of
feedbacks that ultimately determine how
much warming we will eventually get. Some
of the key feedbacks are:
• Warming leading to more water vapour (which is
a GHG) in the atmosphere, causing further
warming
• Warming lead to melting back of ice and snow
(which otherwise reflect solar radiation), leading
to more absorption of solar radiation at the
surface and more warming
The key parameter in the whole global warming
issue is called the climate sensitivity.
The is defined as the eventual (i.e., after the
climate system has had enough time to adjust)
global average warming for a fixed doubling of the
atmospheric CO2 concentration
Four independent lines of evidence are in
broad agreement in indicating that the
climate sensitivity is highly likely
(say, 90% probability) to lie between 1.5ºC
and 4.5ºC.
That is, we expect each CO2 doubling (or its
radiative equivalent) to eventually warm the
climate by 1.5-4.5 C in the global mean.
The four lines of evidence are:
• Simulations of individual feedback processes
with 3-D coupled atmosphere-ocean climate
models
• Comparison of observed global average
warming over the past century (0.6-0.8ºC) and
the gradual increase in estimated net radiative
forcing (as GHGs have increased in
concentration) over this time period
• Comparison of estimated global mean
temperature changes and radiative forcings at
various times during the geological past
• Comparison of inferred and simulated natural
variations in the atmospheric CO2 concentration
during the last few 100 million years with
different assumed values for the climate
sensitivity (which plays a critical role in initiating
processes that eventually limit the magnitude of
slow, natural fluctuations in CO2 concentration)
Thus, by the time we get the radiative equivalent of
4 x pre-industrial CO2 concentration (the end of
this century under business-as-usual scenarios),
we can expect an eventual global mean warming
of 3.0-9.0ºC (2 doublings at 1.5-4.5ºC each,
assuming a linear response)
Figure 1.4 Global mean temperature change for business-as-usual and
aggressive (near zero emissions before 2100) emission-reduction
scenarios in which the CO2 concentration is stabilized at 450 ppmv
o
Temperature Change ( C)
7
6
BAU, DT2x=4oC
5
Stabilization, DT2x=4oC
4
BAU, DT2x=2oC
3
2
Observed
1
0
-1
1850
Stabilization, DT2x=2oC
1900
1950
2000
Year
2050
2100
Supplemental Discussion: What
has been observed so far?
Figure 1.2 Variation in global average surface temperature,
1856-2009
0.6
o
Temperature Change ( C)
0.4
0.2
0.0
-0.2
-0.4
-0.6
1856
1881
1906
1931
Year
1956
1981
2006
Figure 1.3 Reconstructed and directly observed (‘Instrumental’)
variation in NH surface temperature
0.8
Esper 2002
Temperature Change (o C)
0.6
Huang 2004
Rutherford 2005
Moberg 2005
0.4
Mann et al 2008
Instrumental
0.2
0.0
-0.2
-0.4
-0.6
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100
Year
Figure 1.5 Business as usual change in global mean temperature in the
context of observed or inferred past variations
5
Pessimistic Projection
Optimistic Projection
o
Temperature Change ( C)
4
3
2
1
Various Inferred
Variations
Observed
0
-1
1000
1200
1400
1600
Year
1800
2000
2200
Sea ice extent, Sept 2005 (white) and
average extent during the 1980s (pink line)
Source: National Snow and Ice Data Center (NSIDC), USA, http://nsidc.org/news
Sea ice extent, Sept 2007
Source: NSIDC, http://nsidc.org/news
Sea ice extent, Sept 2009
Source: NSIDC, http://nsidc.org/news
September 2010
September 2012
Exhibit 1-40: Minimum annual extent of Arctic sea
ice (occurring in Sept of each year)
Source of data: National Snow and Ice Data Center, Boulder, Colorado
Summer Melting of Greenland Ice Cap
Source: Konrad Steffen (cires.colorado.edu/steffen/greenland/melt2005)
Source: Fettweis et al (2007),
Geophysical. Research
Letters 34, L05502
Sea level rise – 20 cm since 1880
Source: IPCC 2007, AR4, WG1
Major Impacts of Concern
• Sea level rise of 6-12 m over several
centuries to a 1000 years or more
• Increased occurrence of drought, with
major (20-30% and more) reductions in
food production in many regions
• Increased water stress in vulnerable
regions
• Species extinction (1/3 to ½ this century)
• Acidification of the oceans
Source: Nature 447, 145-147 (2004)
Source: Nature 439, 143-144 (2006)
Source: Nature 442, 978-980 (2006)
Dissolution effects on coccoliths
Source: Ruttimann (Nature 442, 978-980, 2006)
What are the solutions?
• More efficient use of energy
• Moderation in our material demands
• Massive deployment of renewable energy
United Nations Framework
Convention on Climate Change (1992)
• Ratified (and therefore accepted) by almost
every country in the world
• Declares as its goal the “stabilization of
greenhouse gas concentrations in the
atmosphere at a level that prevent dangerous
anthropogenic interference in the climate
system”
• To be “safe” in choosing allowed concentrations,
we have to assume that the climate sensitivity is
near the high end of the uncertainty range (i.e.,
around 4.5ºC)
UNFCC (continued)
• Any given real CO2 concentration corresponds
to a higher effective concentration when we add
in the heating effect of other GHGs
• Thus, 450 ppm CO2 corresponds to at least 560
ppmv (a doubling of the pre-industrial
concentration of 280 ppmv)
• As a doubling could warm the climate by 4.5ºC,
and if this is unacceptable, then we need to keep
the real CO2 concentration to below 450 ppmv if
we are to play it safe (as required by the
UNFCCC).
• We are currently (2012) at about 390 ppmv.
Cancun Accord, Article 4
“The Conference of Parties … recognizes that deep
cuts in global greenhouse gas emissions are required
according to science … with a view to [holding] the
increase in global average temperature below 2oC
above preindustrial levels, and that the Parties should
take urgent action to meet this goal … also
recognizes the need to consider … strengthening the
long-term goal to a global temperature rise of
1.5oC.”
Source: United Nations, Framework Convention on Climate Change, The Cancun Agreements: Outcome of
the work of the Ad Hoc Working Group on Long-term Cooperative Action under the Convention,
FCCC/CP/2010/7/Add.1 (15 March 2011), online: <http://unfccc.int/resource/docs/2010/cop16/eng/07a01.pdf>
Business-as-usual scenario: 3-6oC
global mean warming by 2100
Source: IPCC AR5, WG1, SPM Fig. 7a
Table 1 of WG2 SPM summarizes the risks of 2oC
and 4oC global mean warming in such areas as:
•
•
•
•
•
•
•
Wildfires
Drought
Food production
Forest health
Human health are mortality
Sea level rise
Ocean acidification (caused by the CO2
increase associated with various amounts of
warming)
AR5 WG2 finds that
• “Very High” risks are expected in almost all
impact areas with 4ºC warming and current
levels of adaptation. These risks can be reduced
to “medium” in some sectors with high levels of
adaptation
• “Medium” to “Very High” risks are expected even
for a 2ºC warming with current levels of
adaptation. These risks can be reduced to
“Medium” for all sectors with strong adaptation.
Total allowed cumulative emissions vs allowed
global mean warming
Source: IPCC AR5, WG1, SPM Fig 10
Where is Canada heading?
Canadian conventional and tar sands oil
production, historical and industry hoped-for
•7.0
•Source: CAPP (2013)
•Source: CAPP (2013)
All proposed pipelines and more are needed to
meet tar sands expansion plans
•Source:
•CAPP (2013)
900
862
850
Greenhouse Gases (MT CO2eq)
without measures
Reductions from
"without measures”
scenario = 128 Mt
800
750
734
historical emissions
700
Additional reductions
required = 122 Mt
with current measures
650
612
600
Canada’s 2020 target
550
1990
1995
2000
2005
2010
2015
2020
Decomposition of past and future fossil
fuel CO2 emissions according to the Kaya
identity
• Emission =
Population x GDP/P x Energy Intensity x
C Intensity, or
• E = P x ($/P) x (MJ/$) x (kgC/MJ)
Figure 1.6b Global population and global mean GDP/P and energy and
carbon intensities
20
Carbon Intensity
9
18
8
7
16
Energy Intensity
14
6
12
5
10
4
8
3
GDP/P
Population
6
2
4
1
2
0
1965
1975
1985
Year
1995
0
2005
Energy Intensity (MJ/$),
Carbon Intensity (kgC/GJ)
Population (billions), GDP/P (1000$/P)
10
Figure 1.6a Global population, GDP, primary energy
demand and CO2 emission
500
Primary Energy, EJ/yr
Emission, GtC/yr
8
400
Population, billions
6
300
4
200
World GDP, 10s trillions $
2
0
1965
1975
1985
Year
1995
100
0
2005
Primary Energy (EJ/yr)
Emission (GtC/yr),
Population (billions), GWP (10s trillions $/yr)
10
Figure 1.8 Hypothetical variation in atmospheric CO2 concentration
leading to stabilization at the indicated concentrations
700
CO2 Concentration (ppmv)
750 ppmv
650 ppmv
600
550 ppmv
500
450 ppmv
400
350 ppmv
300
2000
2025
2050
Year
2075
2100
Figure 1.9a: C emissions under BAU and as allowed
for stabilization at various CO2 concentrations
Figure 1.9b: Primary power from fossil fuels under BAU and
permitted with stabilization at 450 ppmv CO2
Simplification of Figure 1.9b
C-Free Primary Power (TW)
Figure 1.9c Carbon-free primary power supply required for
stabilization at various CO2 concentrations, given BAU growth in
energy demand
40
35
30
25
2005 world
total primary
power
demand
350
450
550
20
650
750
15
10
5
0
2000
BAU
2020
2040
2060
Year
2080
2100
The preceding projection of energy demand,
and the required C-free power supply for
stabilization of CO2 at 450 ppmv, assumes
that energy intensity (MJ/$) decreases by
only 1%/yr. If it decreased at a fast rate, the
growth in total energy demand would be
smaller, so – for a given allowed (and
declining) fossil fuel supply, the require Cfree power supply would be smaller.
Required Carbon-Free Power (TW)
Figure 1.10: Trade-off between the rate of decrease in energy
intensity and the amount of C-free power required in 2025, 2050,
2075, and 2100 for stabilization of atmospheric CO2 at 450 ppmv
40
Total Primary Power in 2005
2100
30
2075
C-free Primary Power in 2005
20
2050
10
2025
0
1.0
1.5
2.0
2.5
Rate of Energy Intensity Decline (%/yr)
3.0
Recall: Decomposition of past and future
fossil fuel CO2 emissions according to
the Kaya identity
• Emission =
Population x GDP/P x Energy Intensity x
C Intensity, or
• E = P x ($/P) x (MJ/$) x (kgC/MJ)
Thus:
• To stabilize atmospheric CO2 at no more than 450 ppmv
(and possibly declining thereafter) requires (for the
baseline population and GDP/P assumptions) either 21
TW of C-free power by 2050 (almost 1.5 times current
total world primary power demand) and continuation of
the recent rate of improvement of global mean energy
intensity by 1%/yr, or
• Accelerating the rate of improvement of energy intensity
to an average of 3.0%/yr between 2005-2050 and
increasing the current C-free primary power supply by
about 50%, or
• Some combination involving partial achievement of both
the energy efficiency and C-free power supply
requirements given above.
Figure 1.11 Tranches of carbon-free power required with
progressively smaller rates of decrease in energy intensity
Extra for 1.0%/yr vs 1.5%/yr
Extra for 1.5%/yr vs 2.0%/yr
Extra for 2.0%/yr vs 2.5%/yr
Extra for 2.5%/yr vs 3.0%/yr
For 3.0%/yr
35
30
25
20
15
10
5
00
21
90
20
80
20
70
20
60
20
50
20
40
20
30
20
20
20
10
20
00
0
20
Primary Power (TW)
40
Figure 1.12 Factor by which energy intensity decreases for
various annual rates of decrease
5.0
3.0%/yr
2.5%/yr
Factor
4.0
2.0%/yr
1.5%/yr
3.0
1.0%/yr
2.0
1.0
0.0
2000
2010
2020
2030
Year
2040
2050
Summary on Global Warming
• The world’s climate is warming (almost 1ºC in the global
average since late 1800s), and on this there is near
unanimous scientific agreement
• This warming is largely due to human emissions of
GHGs, and on this there is also almost as unanimous
scientific agreement
• Warming could reach 3-6ºC by the end of this century
under business-as-usual assumptions, and more the
following century, with dire consequences (strong
scientific agreement),
• There is, however, much that we can do to greatly
reduce (but, unfortunately, not eliminate) further warming
– but it will require fundamental changes in our energy
systems and ways of thinking but (I will argue later) with
little real impact on our standard of living