Transcript environmental science & services - level 1

Low Carbon Buildings and
Sustainability
By Dr David Johnston – licensed under the Creative Commons Attribution – Non-Commercial –
Share Alike License
http://creativecommons.org/licenses/by-nc-sa/2.5/
ENVIRONMENTAL SCIENCE & SERVICES LEVEL 1
Introduction
Dr. David Johnston
Module aim
The aim of this module is to:

Develop an understanding of the scientific principles involved in the
environmental design of buildings, together with the provision of building
services systems.
Learning outcomes and competencies
On completion of this module, students should be able to:

Define and use appropriate technical and scientific terminology.

Identify the basic principles of environmental design.

Apply these basic principles to the design of simple elements to meet
environmental requirements within the current statutory framework.
 Describe different types of building services installations applied to a
range of building types and the principles involved in their design.
Module content
The module content will encompass the following subjects:

Global Environmental Issues

The Impact of Buildings on the Environment

Thermal Comfort
 Heat Loss and Thermal Performance of Buildings

Thermal Modelling of Buildings

Condensation

Acoustics

Energy Resources and Supply

CHP and District Heating Systems

Space Heating Systems

Hot Water Supply Systems

Active and Passive Solar Systems

Natural and Mechanical Ventilation

Air Conditioning

Natural and Artificial Lighting
Key skills
In addition to developing subject specific knowledge and understanding, the module
will also help you to develop a number of generic key skills.
Specific key skills which this module will help to develop are outlined below.
●
Technical Skills (developed throughout module and assessed in end
examination).
●
Theory and principles (developed throughout module and assessed in
phase examination and end examination).
●
Analysis and Reflection (developed throughout module and assessed in
end examination).
●
Application and Reflection (developed throughout module and assessed in
end examination).
ENVIRONMENTAL SCIENCE & SERVICES LEVEL 1
Impact of buildings on the global climate
Dr. David Johnston
Objectives
By the end of this lecture you should be able to:
 Identify the ways in which the built environment can have an adverse
effect on the natural environment.
 Identify the ways in which the built environment can contribute to global
atmospheric pollution.
 Understand the processes involved in:
 the greenhouse effect.
 the destruction of the ozone layer.
 acid deposition.
 Identify the main contributors to these processes.
Introduction
Introduction
Buildings can have a number of adverse effects on the natural environment. These
include:
 Depletion of natural resources – Over 90% of non-energy minerals (mainly
aggregates) extracted in the UK are supplied as construction materials. The
construction and demolition industry contributes 33% to the volume of the UK’s
waste.
 Changes in land use – Supply of land is limited. Although the emphasis of
current Government policy is to build new housing on brownfield land, in 2005
23% of dwellings were built on undeveloped (green) land. This proportion is
likely to increase as demand for housing grows.
 Destruction of habitats and ecosystems – In the last century, over 100
species have been lost and many more species and habitats are in danger of
disappearing.
 Changes to the global climate – Main changes include:
 Global warming.
 Destruction of the ozone layer.
 Acid deposition.
Global warming
Global climate
The greenhouse effect is a natural phenomenon in which short wave radiation emitted
from the sun penetrates the Earth's atmosphere and warms the Earth's surface.
Infra-red (longwave) radiation is then emitted from the Earth’s surface, some of which is
absorbed by gases in the atmosphere (greenhouse gases). This warms the Earth and the
lower atmosphere.
Short wave
radiation
Natural greenhouse
gases:
Infra-red
radiation
•Water vapour
•CO2
•CH4
The greenhouse effect [Source: Royal Commission on Environmental Pollution, 2000]
The ‘natural’ greenhouse effect keeps the Earth 33OC warmer than it would otherwise be,
at an average of 15OC, allowing life as we know it on Earth to exist. In contrast, the moon
has an average surface temperature of -15OC.
Global climate
Over the last 250 years, various anthropogenic (human generated) activities have
altered the composition of the global atmosphere mainly as a direct result of
industrial activity.
The release of these gases has led to an increase in the concentrations of the
earth’s greenhouse gases. Therefore, more of the infra-red radiation emitted by the
Earth’s surface is being trapped.
Anthropogenic
activities have led
to increased
concentrations of
greenhouse gases.
The greenhouse effect [Source: Royal Commission on Environmental Pollution, 2000]
This change has been commonly referred to as the ‘enhanced’ greenhouse effect.
Anthropogenic greenhouse gases
The balance of current scientific opinion is that changes to the global climate are taking
place, and these changes are taking place primarily due to the increase in the production
of anthropogenic greenhouse gases
As anthropogenic greenhouse gas concentrations in the atmosphere increase, more
heat is trapped in the Earth’s atmosphere resulting in the enhanced greenhouse effect
and global warming.
The IPCC stated in their Fourth Assessment
Report ‘Climate Change 2007’ that:
“Most of the observed increase in global
average temperatures since the mid20th century is very likely due to the
observed increase in anthropogenic
greenhouse gas concentrations”
(IPCC, 2007 p.10).
Comparison of observed continental- and globalscale changes in surface temperature
[Source: IPCC, 2007]
Greenhouse gases
Greenhouse gases are gases that have a large influence on the greenhouse
effect.
The most important greenhouse gases are : Water vapour – causes about 36-70% of the greenhouse effect.
 Carbon dioxide (CO2) – causes about 9-26% of the greenhouse effect.
 Methane (CH4) – causes about 4-9% of the greenhouse effect.
 Ozone – causes about 3-7% of the greenhouse effect.
Other powerful greenhouse gases include:
 Nitrous oxide (N2O).
 Sulphur hexafluoride (SF6).
 Chlorofluorocarbons (CFCs).
 Hydrofluorocarbons (HFCs).
 Hydrochlorofluorocarbons (HCFCs).
 Perfluorocarbons (PFCs).
 Related bromide compounds.
 Many Volatile Organic Compounds (VOCs).
Some of these gases occur naturally, some occur only as a result of human
activity, and others occur both naturally and as a result of human activity.
Greenhouse gases
The ability of each greenhouse gas to contribute to global warming varies
considerably and is dependent upon:

Atmospheric lifetime – how many years the gas remains in the atmosphere.

Global Warming Potential (GWP) – a relative measure of how effective the gas
is at preventing the passage of infra-red radiation.

Atmospheric concentration – usually measured in parts per million (ppm).
The GWPs1 for some of the most important greenhouse gases are as follows:
Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (N2O)
CFC-12
HCFC-22
1
Time Horizon
20 years
100 years
1
1
62
23
275
296
7900
8500
4300
1700
500 years
1
7
156
4200
520
GWP is the ratio of global warming from one unit mass of a greenhouse gas to that of one unit
mass of CO2 over a set time period.
Greenhouse gases
Water vapour is the most important greenhouse gas, although its concentration in
the atmosphere is not directly influenced by human activity. However, its
concentration is influenced indirectly as any increase in global temperatures will
increase concentrations, as warmer air can hold more water.
Although CO2 is not the most potent greenhouse gas, it is causing the greatest
concern, due to:

Its vast concentration in the atmosphere – Concentration has increased
sharply due to human activities.

Its long atmospheric lifetime – CO2 remains in the atmosphere for 50-200
years.
95% of CO2 emissions come from the combustion of fossil fuels.
The combustion of fossil fuels releases CO2 into the atmosphere which had been
previously been fixed by the biosphere over many millions of years, and thus
increases the concentration of CO2 in the atmosphere..
CO2 emissions contribute around 70% of the potential global warming effect of
anthropogenic emissions of greenhouse gases.
UK greenhouse gas emissions
In 2006, UK emissions of the basket of six greenhouse gases covered by the
Kyoto Protocol were estimated to be equivalent to 653 million tonnes of carbon
dioxide.
UK total greenhouse gas emissions [Source: DEFRA, 2009]


Emissions have reduced by 15% over the period 1990 to 2006.
Emissions in 2006 were 0.5% less than they were in 2005.
In the UK, CO2 is the main greenhouse gas, accounting for around 85% of total
greenhouse gas emissions in 2006.
UK greenhouse gas emissions
CO2 emissions by source: 1990-2006
[Source: DEFRA, 2009]
NO2 emissions by source: 1990-2006
[Source: DEFRA, 2009]
Methane emissions by source: 1990-2006
[Source: DEFRA, 2009]
UK CO2 emissions
One of the sectors which contributes substantially to CO2 emissions is the built
environment. In the UK, as in most industrialised countries, the domestic sector
contributes substantially to national CO2 emissions.
There are over 24 million dwellings in the UK, and in 2006 they were responsible
for 27% of the UK’s total CO2 emissions by end user (DEFRA, 2009).
Increased by
12% over period
Reduced by 4%
over period
CO2 emissions by end use: 1990-2004 [Source: DEFRA, 2009]
Important to realise that the UK housing stock is also characterised by long physical
lifetimes and slow stock turnover.
Global carbon cycle
The concentration of CO2 within the atmosphere is the outcome of a natural cycle.
CO2 is continuously released into the atmosphere and re-absorbed by rocks, organic
material and the oceans.
The global carbon cycle [Source: Royal Commission on Environmental Pollution, 2000]
Over the last 250 years:
Mining and burning of fossil fuels
Oceans have absorbed about
Forest clearance, changes in land use
Net increase is
+260GtC
-140GtC
+50GtC
+170GtC
Global carbon cycle
Over the last 400,000 years, natural variations have occurred in the carbon cycle. The
figure below shows how natural variations In CO2 concentration relate to changes in
temperature.
Changes in CO2
Changes in
temperature
CO2 concentration and temperature evidence from ice cores
[Source: Royal Commission on Environmental Pollution, 2000]

All the significant changes that have occurred in the CO2 concentration have
been associated with a significant change in temperature.
Global carbon cycle
Monthly mean atmospheric CO2 concentration at Mauna Loa Observatory, Hawaii.
[Source: Earth System research Laboratory, 2009]


The present concentration of CO2 in the atmosphere is around 380ppmv, which is
much greater than anything that has been recorded over the last half million
years.
Pre-industrial concentration was around 280ppmv in 1750.
Global warming
The precise effect of the increase in CO2 concentration on the global climate cannot
be predicted with certainty. However, most analyses indicate that it has probably lead
to global warming.
Combined global land and marine surface temperature record from 1856-2007 [Source: Climatic Research Unit, 2009]



2007 was the eighth warmest year on record, exceeded by 1998, 2005, 2003,
2002, 2004, 2006 and 2001.
The 1990s were the warmest complete decade in the series.
Twelve of the thirteen warmest years in the series have occurred in the past
thirteen years (1995 – 2007).
Global warming
Model simulations also suggest that the observed increase in the CO2 concentration
has probably contributed to most of the observed warming over the last 50 years.
Temperature change model simulations using the latest Met Office Hadley Centre model
[Source: Met Office, 2009a]
Global warming myths
Two main global warming myths:

Global warming is caused by changes in the Sun’s energy.

The intensity of cosmic rays changes the climate by altering cloud cover.
Solar activity 1850-2007 [Source: Met Office, 2009a]


Changes in solar activity do affect global temperatures, but recent changes in
global temperatures cannot be linked to solar activity alone.
No evidence that cosmic rays have decreased over the last 30 years resulting
in less cloud cover.
Effects of global warming
We are already experiencing some of the effects of global warming:

The number of Category 4 and 5 hurricanes has almost doubled in the last
30 years.

Malaria has spread to higher altitudes in places like the Columbian Andes,
7000 feet above sea level.

The flow of ice from glaciers in Greenland has more than doubled over the
last decade.

At least 279 species of plants and animals are already responding to
global warming, moving closer to the poles.
(An Inconvenient Truth, 2006)
Effects of global warming
IPCC projections indicate that by the end of the 21st century, global warming is
likely to result in:

An increase in the globally averaged surface temperature of 1.8 to 4ºC.

An increase in global mean sea level of 18 to 59cm.

A decrease in snow cover and shrinkage in sea-ice extent in both the Artic
and Antarctic.

It is likely that future tropical cyclones (typhoons and hurricanes) will
become more intense.

It is very likely that there will be an increase in the amount of precipitation
in high latitudes and likely that precipitation will decrease in most
subtropical land regions (by as much as 20% by 2100).

Both past and future anthropogenic CO2 emissions will contribute to
global warming and sea level rise for more than a millennium, due to the
timescales involved.
(IPCC, 2007)
Predicted temperature rise and sea ice coverage [Source: Met Office, 2009b]
Effects of global warming
The UK is unlikely to experience some
of the more severe effects associated
with climate change.
Nevertheless, significant changes are
still expected to occur:

A 2 to 3.5ºC increase in average
annual temperature by the 2080s.

An increase in the temperature of
UK coastal waters.

An increase in the frequency of
high summer temperatures.

An increase in winter rainfall.

A rise in the relative sea level
around most the UK’s shoreline.

An increase in the frequency of
extreme sea levels.

A weakening of the Gulf Stream.
(Hulme, Jenkins, Lu, Turnpenny, Mitchell, Jones, Lowe,
Murphy, Hassell, Boorman, McDonald & Hill, 2002)
Response to global warming
Various attempts have been made to estimate the scale of the reductions that will be
required to stabilise atmospheric CO2 concentrations over various time-scales.
The estimates vary from approximately a 60% to a 90% reduction in current CO2
emissions by the year 2050.
Fossil carbon emissions (GtC/year)
7
Industrialised Countries
6
Developing Countries
World
5
4
3
2
1
0
1980
1990
2000
2010
2020
2030
2040
2050
2060
2070
2080
2090
2100
Year
Carbon emission rates for the 300GtC global fossil carbon budget [Source: Krause, Bach & Koomey, 1990]


Suggest that target should be achieved by dividing the reductions between the
industrialised and developing countries.
Intended to address the highly asymmetrical distribution of emissions per capita
(~11:1).
Response to global warming
The IPCC have also defined a number of CO2 emission profiles that will result in
stabilisation of the atmospheric CO2 concentration.
1100
CO2 concentration (ppm)
1000
900
800
Only emission
profile to result in
CO2 stabilisation
by the end of the
21st century.
700
600
500
400
450 ppm scenario
550 ppm scenario
650 ppm scenario
750 ppm scenario
1000 ppm scenario
300
200
100
0
2000
2050
2100
2150
2200
2250
2300
Year
IPCC atmospheric CO2 emission stabilisation scenario [Adapted from: IPCC, 2001]



Only the 450ppm/650GtC profile will result in the stabilisation of the atmospheric
concentration by the end of the 21st century.
Assuming that the reductions are equally divided between the industrialised and
the developing countries, CO2 emission reductions of approximately 60% will be
required in the industrialised countries by the year 2050.
These sorts of reductions have been proposed by the Royal Commission on
Environmental Pollution (Royal Commission on Environmental Pollution, 2000).
UK’s response to global warming
In 1997, the Kyoto Protocol was ratified, committing the UK to a legally binding
target of reducing emissions of the six main greenhouse gases by 12.5%, based
on 1990 levels, between 2008 and 2012.
Following the Kyoto Protocol, the UK Government set a more ambitious target of
seeking national reductions in CO2 emissions of 20% by the year 2010.
In 2000, the Royal Commission on Environmental Pollution (RCEP) proposed
that the UK should reduce its CO2 emissions by 60% by 2050. This was accepted
by the UK Government and was used for policy making.
The Climate Change Bill was introduced into Parliament in November 2007 and
became law (the Climate Change Act) on the 26th November 2008. The Act sets a
series of clear targets for reducing UK CO2 emissions.
The target for 2050 is at least an 80% reduction in CO2 emissions, based on 1990
levels. Also a reduction in CO2 emissions of at least 34% by 2020.
In May 2009, carbon budgets were set for 3 separate time periods:
% reduction on 1990 levels
2008-12
22
2013-17
28
2018-22
34
Destruction of the ozone layer
The ozone layer
Ozone (O3) occurs naturally throughout the atmosphere.
The majority of ozone (about 90%) is found in the stratosphere, a region that
begins about 10km above the Earth’s surface and extends up to about 50km. Most
ozone resides in the stratosphere in what is commonly known as the ozone layer.
The remaining ozone, about 10%, is found in the troposphere, the lowest region of
the atmosphere.
90% of ozone
found in this zone.
The Earth’s atmosphere [Source: Centre for Atmospheric Science, 2006]
The ozone layer in the stratosphere is thinnest in the tropics (around the equator)
and denser towards the poles.
The ozone layer
Ozone helps to protect human beings, other biological systems and man-made
materials from the harmful effects of certain wavelengths of sunlight.
The ozone layer in the stratosphere helps to absorbs potentially harmful UV-B
radiation (280-315 nm wavelength) coming from the Sun, allowing only
reduced amounts to penetrate to the Earth’s surface. UV-A (315-400 nm
wavelength) and other solar radiation are not strongly absorbed by the ozone
layer.
UV protection by the ozone layer [Source: Fahey, 2002]
Without the ozone layer, life on Earth would not be possible.
The ozone layer
The ozone in the stratosphere is created when ultraviolet radiation (sunlight)
strikes the stratosphere, dissociating (or splitting) oxygen molecules (O2) to form
atomic oxygen (O). The atomic oxygen quickly combines with further oxygen
molecules to form ozone (O3):
Stratospheric Ozone Production [Source: Fahey, 2002]
The amount of ozone above a particular point on the Earth’s surface is measured
using Dobson units (DU).
Ozone is typically around 260 DU near the tropics and higher elsewhere, although
there are seasonal fluctuations.
Destruction of the ozone layer
Recent evidence indicates that the ozone layer is
thinning in certain areas, and ozone ‘holes’ have
developed.
It is the ozone in the stratosphere over Antarctica
that is giving the greatest cause for concern – owing
to climatic conditions, the ozone over the Antarctic is
particularly susceptible to ozone depletion at certain
times of the year.
Ozone depletion is most marked in the Antarctic
Spring, around October.
There is also evidence that the ozone layer is
thinning, albeit less extensively, throughout the
world.
Total Ozone above Halley Bay Station, Antarctica
[Source: Centre for Atmospheric Science, 2006]
Destruction of the ozone layer
TOMS (Total Ozone Mapping Spectrometer) satellite measurements of ozone
levels over Antarctica.
Changes in Antarctic Ozone Levels
[Source: Centre for Atmospheric Science, 2006]
Destruction of the ozone layer
The amount of ozone depleted and the dates when the ozone depletion starts and
finishes varies from year to year and is dependent upon the meteorology of the
atmosphere.
Monthly averages in Antarctic ozone for October
[Source: Centre for Atmospheric Science, 2006]
Destruction of the ozone layer
Size and depth of this years ozone hole [Source: NASA, 2007]
Destruction of the ozone layer
The ozone in the stratosphere is continually being created and destroyed by
natural chemical reactions and processes that involve sunlight (photochemical).
Until recently, this process has been in equilibrium:
the amount of ozone created ≈ amount of ozone destroyed
However, recent anthropogenically produced catalysts and trace gases have
been accumulating in the atmosphere, and are thought to be altering and
destroying the ozone layer without any compensating increase in the rate at which
it is produced.
Gases of particular concern include a group of synthetically produced chlorine
containing chemical substances known as CFCs and HCFCs. These have been
used for:

Refrigeration systems.

Air conditioning systems.

Aerosol propellants.

Solvents.

Blowing agents for foams

Cleaning of metals and electronic components.
Other compounds containing bromide, other related halogen compounds and also
nitrogen oxides (NOx) also contribute to ozone depletion.
Destruction of the ozone layer
CFCs and HCFCs have been used due to a number of important properties:

Their chemical stability - they are non-inflammable, non-toxic, non-poisonous.

Cost-effective.

Non-corrosive.
However, CFCs and HCFCs have such long residence times in the atmosphere that
only a fraction of the amount released each year is broken down and taken out of
circulation by natural processes.
Atmospheric lifetimes, emissions and ozone depletion
potentials of halogen gas sources [Source: Fahey, 2002]
Destruction of the ozone layer
Schematic illustrating the lifecycle of CFCs [Source: Centre for Atmospheric Science, 2006]
Destruction of the ozone layer
When the CFCs and HCFCs are broken down in the stratosphere by sunlight, various
products are produced. The most important of these are a number of long-lived
inorganic carriers of chlorine; hydrochloric acid (HCl) and chlorine nitrate
(ClONO2).
Evolution of ClONO2 over North Pole during winter 1994
[Source: Centre for Atmospheric Science, 2006]
Destruction of the ozone layer
Depletion of stratospheric ozone can lead to damaging effects on human health and the
environment:

Directly - increased penetration of UV-B radiation.

Indirectly - changes in the distribution of stratospheric ozone and water vapour that
contribute to global warming effects and altered climatic conditions.
The effects of an increase in the amount of UV-B radiation reaching the Earth’s surface
are serious:

Human health:
- Greatest threat is an increase in skin cancer. Each 1% loss of total ozone leads to a 3
to 5% increase in skin cancer cases.
- Eye disease, such as cataracts and temporary disorders such as ‘snow blindness’.
- UV-B suppresses the immune system.

Marine environment:
- Likely to be a reduction in the numbers of photoplankton and photosynthesising
organisms in the sea.
- UV-B causes direct damage to young fish, shrimp and crab larvae, and other small
animals. Results in a reduction in food stocks further up the food chain.

Agriculture and plant life:
- High concentrations of UV radiation can stunt the growth and leaf development of
most plant varieties.
- UV sensitive plants would be more susceptible to pests and disease.

Material degradation:
- Useful life of plastics can be reduced when exposed to UV radiation.
Destruction of the ozone layer
UV radiation at the Earth’s surface that causes sunburn has increased over the
globe between 1979 and 1992.
Changes in surface UV radiation [Source: Fahey, 2002]
Destruction of the ozone layer
In response to fears about damage to the ozone
layer, the production of ozone depleting gases is
regulated under a 1987 international agreement
known as the ‘Montreal Protocol on Substances
that Deplete the Ozone Layer’ and its subsequent
Amendments.
The Protocol, now ratified by over 180 nations,
establishes legally binding controls on the national
production and consumption of ozone depleting
gases.
Production and consumption of all principal
halogen containing gases by developed and
developing nations will be significantly phased out
before the middle of the 21st century.
Effect of the Montreal Protocol
[Source: Fahey, 2002]
Destruction of the ozone layer
Past and future abundance of atmospheric halogen source gases [Source: Fahey, 2002]
Acid deposition
Acid deposition
This is a term used to refer to the various processes by which acidic gases and
particles are deposited on land and water.
The acidic pollutants reach the earth’s surface via two pathways:

Dry deposition – the acidic pollutants are deposited on plants, trees, soils and
water surfaces via gases or dust. Combines with fog and dust to produce smog.
About half of the acidity in the atmosphere falls back to earth through dry
deposition.

Wet deposition - when the pollutants fall to the ground through incorporation in
rain drops, snow, sleet, mist or fog.
Dry and wet deposition [Source: US Environmental Protection Agency, 2006]
During the 1980’s, acid rain was a major environmental issue.
Acid deposition
Acid deposition occurs both naturally and as a result of human activities.
Natural

Absorption of CO2 by water leading to the formation of mild carbonic acid.

Thunderstorms which provide the energy to generate NOX from Nitrogen
and Oxygen.

Volcanic activity and fires which produce SO2.
Anthropogenic

The burning of coal and oil for heating, electrical energy generation and
transport.

Smelting processes.

Industrial activities.
Main contributors are SOX and NOX from fossil fuel combustion and road
transport.
Acid deposition
Since the emission of pollutants is heavily concentrated in the northern
hemisphere, particularly Europe and North America, precipitation is generally
acidic in these countries.
The distances that the acidic pollutants can travel means that acid deposition
is a transboundary problem. For instance, industrial pollution from the UK is
blown across the sea and falls as acid rain in Norway and Sweden.
Acid deposition can lead to the following consequences:

it can damage or kill trees.

it can inhibit plant growth and reduce crop yields.

freshwater can be made toxic.

it can cause disruption to the food chain.

it can damage buildings by eroding away limestone and marble and
corroding steel reinforcement within concrete structures.
In Sweden, over 18,000 lakes have become so acidic due to acid rain that all the
fish have died.
In parts of Germany, more than 70,000 square kilometres of forests have died
because of acid rain.
Acid deposition
Materials such as limestone, marble and sandstone are particularly vulnerable to
acid deposition.
The effects of acid deposition are therefore greater on
ancient monuments, rather than on modern buildings.
York Minster and Westminster Abbey have been
severely eroded in recent years.
Other buildings, such as the Taj Mahal in India, the
Statue of Liberty in New York and the Colosseum in
Rome, have also suffered deterioration due to acid
deposition.
Masonry dissolved by acid rain.
Acid deposition
In recent years, the UK and other Governments have taken steps to reduce acid gas
emissions.
Steps have included:

Fitting desulphurisation plant to many power stations.

Catalytic converters on new motor vehicles.
Unfortunately, both of these measures result in a reduction in fuel efficiency, resulting in
higher CO2 emissions for a given energy output.
Reductions in emissions have also been achieved by switching to ‘cleaner’ fuels, such as
natural gas. Although this reduces SO2 emissions, it does not reduce NOx emissions.
Examples of dwellings that minimise their impact on the
global environment
Examples
The Hockerton Housing Project, Southwell, Nottinghamshire









The UK’s first earth-sheltered, self-sufficient ecological housing development.
A terrace of five single storey earth-sheltered dwellings (four 3 bedroom with internal floor area
of 122m2 and one 4 bedroom with an internal floor area of 140m2).
Superinsulated and airtight construction incorporating passive solar design.
Environmentally friendly materials used throughout.
Rainwater is filtered and collected for drinking.
Sewage is treated in a reed bed.
Wind turbine.
Areas for crop cultivation and rearing of animals.
Only one fossil-fuelled car permitted per household.
Examples
The Autonomous Urban House, Southwell, Nottinghamshire

The UK’s first ‘autonomous’ house.
2½ storey, four bedroom detached house with an internal floor area of 169m2 (excluding the
unheated basement).
Superinsulated and airtight construction incorporating passive solar design.
Environmentally friendly materials used throughout.
Recycled materials used during the construction.
Rainwater is collected from the roof and is stored in the basement.
Clivius Multrum composting toilet. Produces an odourless fertilizer which is used in the garden.

2.2kW grid-connected PV system.






Examples
The Beddington Zero Energy Development (BedZed), Sutton, London [Source: BedZed, 2002]







Design objective is to achieve zero net CO2 emissions by avoiding the use of fossil fuels.
A mixed development containing 82 dwellings which will be a mixture of flats, maisonettes and
town houses and approximately 2500m2 of workspace/office and community accommodation.
Superinsulated and airtight construction.
Wood fuelled CHP plant.
Rainwater collected, stored and recycled.
Large areas of PV’s installed on buildings.
Where possible, materials and equipment sourced from within a 35 mile radius.
References
AN INCONVENIRENT TRUTH (2006) What is Global Warming? Available from
<http://wwww.aninconvenienttruth.co.uk [Accessed 29th September 2006].
BEDZED (2002) Beddington Zero Energy Development. Available from:http://www.bedzed.org.uk [Accessed 3rd
October, 2002].
CENTRE FOR ATMOSPHERIC SCIENCE (2006) The Ozone Hole Tour Part III: The Science of the Ozone
Hole.
Available from: <http://www.atm.ch.cam.ac.uk/tour/part3.html> [Accessed October 5 th, 2006].
CLIMATIC RESEARCH UNIT (2009) Global Temperature Record. Available from:
<http://www.cru.uea.ac.uk/cru/info/warming/> [Accessed January 13 tht, 2009].
DEFRA (2009) e-Digest Statistics about: Climate Change. [Internet]. Available from:
<http://www.defra.gov.uk/environment/statistics/globatmos/index.htm> [Accessed January 13 th, 2009].
EARTH SYSTEM RESEARCH LABORATORY (2007) Atmospheric Carbon Dioxide – Mauna Loa. [Internet],
Washington DC, USA, National Oceanic and Atmospheric Administration. Available from:
<http://www.esrl.noaa.gov/gmd/ccgg/trends/co2_data_mlo.html> [Accessed January 13 th, 2009].
FAHEY, D. W. (2002) Twenty Questions and Answers About the Ozone Layer. US Environmental protection
Agency.
HOUGHTON, J. T. JENKINS, G. J. and EPHRAUMS, J. J. (eds.) (1990) Climate Change: The IPCC Scientific
Assessment. Cambridge, Cambridge University Press.
HULME, M. JENKINS, G. J. LU, X. TURNPENNY, J. R. MITCHELL, T. D. JONES, R. G. LOWE, J. MURPHY, J.
M. HASSELL, D. BOORMAN, P. McDONALD, R. and HILL, S. (2002) Climate Change Scenarios for the United
Kingdom: The UKCIP02 Scientific Report. Tyndall Centre for Climate Change Research, School of
Environmental Sciences, Norwich, UK, University of East Anglia.
References (continued)
IPCC (2001) Climate Change 2001: The Scientific Basis. Technical Summary. Geneva, Intergovernmental Panel
on Climate Change.
IPCC (2007) Summary for Policy Makers. In: Climate Change 2007: The Physical Science Basis. Contribution of
Working Group 1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.
[Solomon, S. QUIN, D. MANNING, M. CHEN, Z. MARQUIS, M. AVERYT, K. B. TIGNOR, T.MILLER, H. S.
(eds.). Cambridge, United Kingdom, Cambridge University Press.
KRAUSE, F. BACH, W. and KOOMEY, J. (1990) Energy Policy in the Greenhouse: From Warming Fate to
Warming Limit. London, Earthscan Publications.
MET OFFICE (2009a) Clearer: Make a Difference About the Facts of Climate Change. [Internet] Available from:
<http://www.metoffice.gov.uk/corporate/pressoffice/myths/bigpicture.pdf> [Accessed January 13 th, 2009].
MET OFFICE (2009b) Climate Change Projections. [Internet] Available from:
<http://www.metoffice.gov.uk/climatechange/science/projections/> [Accessed January 13th, 2009].
NASA (2007) Ozone Hole Monitoring. [Internet] Available from:
<http://jwocky.gsfc.nasa.gov/eptoms/dataqual/ozone.html> [Accessed November 2nd, 2007].
ROYAL COMMISSION ON ENVIRONMENTAL POLLUTION (2000) Twenty Second Report. Energy - The
Changing Climate. Royal Commission on Environmental Pollution. London, HMSO.
US ENVIRONMENTAL PROTECTION AGENCY (2006) What is Acid Rain? [Internet] Available from:
<http://www.epa.gov/airmarkt/acidrain/what/index.html> [Accessed October 13th, 2006].