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 harvey@geog.utoronto.ca - PowerPoint PPT Presentation

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Title: 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 harvey@geog.utoronto.ca


1
Energy and the New Reality, Volume 1Energy
Efficiency and the Demand for Energy Services
Chapter 1 Prospective Climatic Change, Impacts
and Constraints L. D. Danny Harveyharvey_at_geog.u
toronto.ca
Publisher Earthscan, UKHomepage
www.earthscan.co.uk/?tabid101807
  • This material is intended for use in lectures,
    presentations and as handouts to students, and is
    provided in Powerpoint format so as to allow
    customization for the individual needs of course
    instructors. Permission of the author and
    publisher is required for any other usage. Please
    see www.earthscan.co.uk for contact details.

2
Controls over the Earths Climate
  • The Earths 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 Earths surface and atmosphere will
    naturally adjust to bring solar absorption and
    infrared emission back into balance

3
The greenhouse effect
  • Refers to the partial absorption by certain gases
    in the atmosphere of infrared radiation emitted
    by the Earths 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
    naturally-occurring greenhouse effect)
  • The key GHGs are water vapour, CO2, ozone (O3),
    methane (CH4) and nitrous oxide (N2O)

4
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

5
Figure 1.1 Variation in CO2 and CH4 Concentration
6
Figure 1.2 Variation in global average surface
temperature, 1856-2010
7
Figure 1.3 Reconstructed and directly observed
(Instrumental) variation in NH surface
temperature
8
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
9
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
10
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

11
  • 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)

12
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)
13
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
14
Figure 1.5 Business as usual change in global
mean temperature in the context of observed or
inferred past variations
15
Supplemental Discussion What has been observed
so far?
16
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
17
Sea ice extent, Sept 2007
Source NSIDC, http//nsidc.org/news
18
Sea ice extent, Sept 2009
Source NSIDC, http//nsidc.org/news
19
Source NSIDC, http//nsidc.org/news
20
Summer Melting of Greenland Ice Cap
Source Konrad Steffen (cires.colorado.edu/steffen
/greenland/melt2005)
21
Source Fettweis et al (2007), Geophysical.
Research Letters 34, L05502
22
Sea level rise 20 cm since 1880
Source IPCC 2007, AR4, WG1
23
Major Impacts of Concern
  • Sea level rise of 6-12 m over several centuries
    to a 1000 years or more
  • Increased occurrence of drought
  • Increased water stress in vulnerable regions
  • Species extinction (1/3 to ½ this century)
  • Acidification of the oceans

24
(No Transcript)
25
Source Nature 438, 303-309 (2005)
26
Areas of the world dependent on winter snowfall
for summer moisture Shown is the ratio of annual
snowfall to annual runoff. The red line outlines
the areas where runoff is predominantly from
snowmelt and there is not adequate storage to
buffer seasonal variations.
Source Barnett et al (2005, Nature 438, 303-309)
27
Source Nature 447, 145-147 (2004)
28
Source Nature 439, 143-144 (2006)
29
Source Nature 442, 978-980 (2006)
30
Dissolution effects on coccoliths
Source Ruttimann (Nature 442, 978-980, 2006)
31
Figure 1.7 Variation in CaCO3 concentration
Source Orr et al (2005, Nature 437, 681686)
32
Coral Reef Ecosystems
33
Staghorn Acropora coral before and after
bleaching, south Great Barrier Reef
Source Ray Berkelmans, Australian Institute of
Marine Sciences (www.aims.gov.au)
34
Methane release from melting yedoma soils in
Siberia below an early fall snowfall
Source Walker (2007, Nature 446, 718-721)
35
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)

36
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 (2010) at about 385 ppmv.

37
Decomposition of past and future fossil fuel CO2
emissions
  • Emission
  • Population x GDP/P x Activity per GDP x
    Energy Intensity (MJ per unit activity) x
  • C Intensity (kgC emission per MJ of energy),
    or
  • E P x (/P) x (A/) (MJ/A) x (kgC/MJ)

38
For buildings, the measure of energy intensity
iskWh per m2 floor area per year of energy use
(kWh/m2/yr)while the measure of activity is
the floor area. Thus(kWh/m2/yr) x (m2/P) x
Population gives total energy use, kWh, per
yearwhere 1 kWh is the energy entailed in 1 kW
of power (1000 W or 1000 J/s) over a period of
one hour (3600 seconds)1 kWh 1000 J/s x 3600
s 3.6 million J (3.6 MJ (megajoules))
39
Energy and the New Reality, Volume 1Energy
Efficiency and the Demand for Energy Services
Chapter 2 Energy Basics L. D. Danny
Harveyharvey_at_geog.utoronto.ca
Publisher Earthscan, UKHomepage
www.earthscan.co.uk/?tabid101807
  • This material is intended for use in lectures,
    presentations and as handouts to students, and is
    provided in Powerpoint format so as to allow
    customization for the individual needs of course
    instructors. Permission of the author and
    publisher is required for any other usage. Please
    see www.earthscan.co.uk for contact details.

40
Forms of energy
  • Primary energy as it is found in nature (coal,
    oil, natural gas in the ground)
  • Secondary energy energy that has been converted
    from primary energy to another form (electricity,
    refined petroleum products, processed natural
    gas)
  • Tertiary energy one more step in the chain
    end-use energy (what we actually want light,
    heat, cooling and mechanical power)

41
Conversions
  • Secondary energy
  • primary energy x conversion efficiency
  • So, given an amount of secondary energy, divide
    by the conversion efficiency to get the amount of
    primary energy required to produce that amount of
    secondary energy

42
Figure 2.1 Primary to Secondary to End-Use Energy
43
Primary Energy Equivalent of Electricity from
Hydropower or Nuclear Power
  • Electricity from hydro and nuclear could instead
    be produced by burning fossil fuels to generate
    electricity
  • So, divide the amount of hydro or nuclear
    electricity by the efficiency in generating
    electricity from fossil fuels to get the primary
    energy equivalent of the hydro or nuclear
    electricity
  • I use a standardized efficiency of 40
  • Thus, 1 MJ of hydro or nuclear (or wind or solar)
    electricity is treated here as the equivalent of
    2.5 MJ of primary energy

44
Energy and Power
  • Energy (the ability to do work) has units of
    joules (J)
  • Power is the rate of supplying energy, and has
    units of watts (W), where 1 W 1 J/s
  • Thus, to convert power to energy used, we
    multiply by the length of time in seconds over
    which the power is supplied, whereas to convert
    the amount of energy used over a given time to
    the average power, we divide energy by time in
    seconds

45
Big Numbers
  • It is convenient to represent global and regional
    annual energy use in units of exajoules, where 1
    EJ 1018 joules, and to represent world power
    demand in gigawatts or terawatts, where 1 GW
    109 watts and 1 TW 1012 watts,
  • so 1 TW1000 GW
  • Primary power (W) demand is given by annual
    energy use (J) divided by the number of seconds
    in one year
  • Thus, total world primary energy use in 2005 of
    483 EJ corresponds to an average rate of supply
    of primary energy (primary power) of 15.3 TW

46
Electrical Energy
  • When it comes to the energy supplied by an
    electrical power plant, it is common to multiply
    the power times the number of hours in the time
    period during which the power is supplied
  • Thus,
  • from kW (kilowatts) we get kWh
    (kilowatt-hours)
  • from GW (gigwatts) we get GWh
    (gigawatt-hours)
  • from TW (terawatts) we get TWh
    (terawatt-hours)
  • To convert energy in units of kWh, GWh or TWh
    into energy in units involving joules, multiply
    by the number of seconds in an hour (and divide
    by the appropriate factor of 10, depending on the
    desired final units)

47
Figure 2.2a Growth in the Use of Primary Energy
48
Figure 2.2b Growth in the use of primary energy
49
Figure 2.3 Variation in the price of crude oil,
1860-2008
50
Figure 2.4 Price of Oil, Natural Gas and Coal
51
Figure 2.5b Growth in Electricity Supply by
Energy Source
52
Figure 2.8 Direct Primary Energy Use in 2005
53
Figure 2.9 Electricity Use By Sector in 2005
54
Figure 2.10 Primary Energy Use by Sector in 2005
(after allocation of energy used to generate
electricity to the sectors that use the
electricity)
55
Energy and the New Reality, Volume 1Energy
Efficiency and the Demand for Energy Services
Chapter 4 Energy Use in Buildings L. D. Danny
Harveyharvey_at_geog.utoronto.ca
Publisher Earthscan, UKHomepage
www.earthscan.co.uk/?tabid101807
  • This material is intended for use in lectures,
    presentations and as handouts to students, and is
    provided in Powerpoint format so as to allow
    customization for the individual needs of course
    instructors. Permission of the author and
    publisher is required for any other usage. Please
    see www.earthscan.co.uk for contact details.

56
OVERVIEW OF ENERGY USE IN BUILDINGS
57
Figure 4.1a Residential Energy Use in the US in
2001
58
Figure 4.1b Residential Energy Use in the EU-15
in 1998
59
Figure 4.1c Residential Energy Use in China in
2005
60
Figure 4.2a Commercial Building Energy Use in
the US in 2003
61
Figure 4.2b Commercial Building Energy Use in the
EU-15 in 1998
62
Figure 4.2c Commercial Building Energy Use in
China in 2005
63
Supplemental figure Average energy intensity of
commercial buildings in different countries in
1990
Source Harvey (2006, A Handbook on Low-energy
Buildings and District-Energy Systems,
Earthscan, London)
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