Construction_Impact_and_Sustainability_p.pptx

Presented By
Arikewushola M. O. (Mrs.)

Presentation Overview
 Global Environmental Issues
 Climate Change Science
 Impact of Construction on the Environment
 Sustainable Development
 Measuring Sustainability
1

Global environmental issues
Environmental concern and international co-operation
is required to address the major issues.
 Carbon Reduction
 Climate change
 Sustainable construction
 Biodiversity
 Deforestation
 Acid rain
 Alternative Energy
2

Climate Change Science
 Climate Change Science is the study of the significant
and long term changes to the Earth’s climate
generated by both natural cycles and the impacts of
human activity’ (Houghton, 2001)
However there is variation in the definition and in some
parts of the world the term ‘Global Warming’ is
synonymous with climate change (even though the term
specifically relates to the greenhouse effect.
 GHGs include: Carbon Dioxide CO2, Methane CH4,
Nitrous Oxide N20, Hydrofluorocarbons HFCs,
Perfluorocarbons PFCs, Sulphur Hexafluoride SF6.
 Global Warming Potential is a relative measure of how
much heat a gas traps in the atmosphere. GWP is the factor
used in carbon accounting to calculate the impact of one
unit of each gas compared to one unit of CO2, typically
averaged over a 100year period.
3

Climate Change Science
 It should be noted that whilst being the most prevalent (at
around 73%), CO2 is not the most potent GHG:
 However focusing on carbon emissions, we risk losing sight
of other important environmental impacts. These include
waste, water use, material resource depletion, and effects
on health and on biodiversity.
Greenhouse Gas Chemical Symbol Global warming
Potential
Carbon Dioxide CO2 1
Methane CH4 23
Nitrous Oxide N20 310
Hydrofluorocarbons HFCs 140-11,700
Perfluorocarbons PFCs 6,500-9,200
Sulphur Hexafluoride SF6 23,900
Source: Intergovernmental Panel on Climate Change, IPCC 2007
4

Ways in which the construction process impacts
upon the environment ;
 Extraction of raw materials
 Manufacture of materials and components
 Noise, dust, dirt and disturbance from construction
sites and their resultant health risks
 Increased pressure on existing services and
infrastructure
 Increased consumption of energy, increased
production of greenhouse gases
Impact of Construction on the Environment
5

 Construction is one of the largest industries in the world,
contributing around 10% to global GDP (Pearce, A 2012).
 The built environment makes a significant contribution to
environmental degradation. Buildings including
construction, operations and deconstruction impacts, use
approximately:
 15% of the world’s fresh water resources;
 40% of the world's energy;
 and produce approximately 23-40% of the world's
greenhouse gas emissions.
 If a reduction in carbon emissions is required to mitigate
climate change then it follows that the construction
industry must change the way buildings and infrastructure
are designed, constructed, operated and demolished.
6

It should be noted that around 17% of a building’s
carbon emissions are emitted during the
construction phase - the remaining 83% are
emitted during the building’s operation.
Source: ICE 2014
7

 Construction and development can have both negative
and positive impacts on the environment. Typically it
can affect some or all of the following:
Land Use
Hydrology and Water Resources
Vegetation and Forest Cover
Nature Conservation
Microclimate
Soil Erosion, Salinization and Fertility
Rangeland/Grazing Degradation
Human Settlement and Population
8

 The following are Change
Indicators relating to construction
with regard to Land Use:
 Loss of actual or potential
cultivated land.
 Loss of areas providing functions of
direct value to society i.e.
watershed protection, wetlands
and recreation, cultural or historic
sites.
 Changes to land tenure and
value.
 Land uses displaced or severed,
including resettlement.
 Improved access and settlement
 Changes to livelihoods based on
land resource exploitation.
 Changes to landscape diversity
and aesthetic quality of natural
or man-made scenery.
9

 The following are Change Indicators
relating to construction with regard to
Hydrology and Water Resources:
 Deterioration in surface and
groundwater quality i.e. direct and
indirect pollution.
 Changes to Hydrologic Flow Regimes i.e.
interruption of drainage, higher flooding
incidence, reduced flow or periodic
drying up of perennial rivers, siltation,
turbidity and sedimentation.
 Depletion of surface and ground
water resources i.e. falling water
tables, drying up of boreholes,
shrinking lakes.
 Increased epidemiological and public
health risks from water pollution.
 Improvement to the quality of water
and wastewater at constructed or
semi-natural facilities.
10

Indicators relating to
construction with regard to
Vegetation and Forest Cover:
 Reduction in vegetation and
forest cover area (absolute and
relative).
 Degradation of vegetation and
forest cover.
 Fragmentation of former
forest cover.
 Absence of natural re-growth.
 Loss of biodiversity.
 Improvements to local eco-
systems and growth patterns
due to project related planting
and ecological management.
11

Indicators relating to
construction with regard to
Nature Conservation:
 Changes to protected areas.
 Increased access to and reduction
in wilderness areas.
 Reduction in biodiversity and
critical habitats.
 Decrease in wildlife or changes to
behaviour patterns.
 Changes to special ecological and
conservation areas.
12

with regard to Microclimate:
 Change in air quality related to
changed land use i.e. emissions
from buildings/vehicles.
 Localised changes to weather i.e. at
very large reservoirs.
 Changes to local ground and air
temperature regimes.
 Changes to local wind patterns
 Changes in natural light levels due
to overshadowing, shading etc.
13

Soil Erosion:
 Extent and severity of surface erosion
i.e. gullies, rills and slips.
 Reduction in erosion due to structural
measures.
 Rate and loss of soil nutrients and
organic matter.
 Evidence of slope instability and mass
erosion.
 Improved slope stability due to
structures.
 River, lake and reservoir sediment loads.
 Rate of soil loss (tonnes per hectare per
year).
14

relating to construction with regard
to Soil Salinization:
 Extent of incidence of soil
salinization measured through
monitoring.
 Increasing salt content of soils
evident through monitoring.
 Irrigated crop failure and yield
reduction through salinization.
 Increasing salinity levels in ground
water tables.
 Soil reclamation due to water
management and drainage
improvements.
15

Agriculture and the Decline of Soil
Fertility:
 Ratio between actual and potential crop
yields under given inputs, management
practices and unchanging weather
conditions.
 Divergence between change in fertilizer
use and change in crop yields.
 Changes in soil properties over time
measured through monitoring.
 Occurrence of specific micronutrient
and soil deficiencies.
 Presence of indicator plants for soil
degradation.
16

with regard to Rangeland
Degradation:
 Off-take of livestock products
monitored over time.
 Reduction in plant cover measured
through direct/remote
monitoring.
 Adverse changes in plant species
composition.
 Extent of areas of trampled,
eroded or gullied land.
 Increased human access and risk
of fire.
17

relating to construction with regard
to Settlement and Population:
 Extent and nature of settlement
pattern changes.
 Increases in unit area population
density.
 Changes in urban land use i.e.
residential to commercial.
 Changes to built environment i.e.
low-rise to high-rise.
 Access to amenities, transport and
communications.
18

The construction industry’s role
If climate change and its impacts are to be tackled
effectively, the construction industry must take a
direct role at 3 levels:-
 Mitigation
 Adaptation
 Secondary Effects
19

Mitigation
 Reducing the impact of energy generation,
transport, construction and operation of
buildings and infrastructure
20

Adaptation
 Engineering the built environment to cope
with the direct impacts of climate change
including extremes of temperature, higher sea
levels and more frequent fluvial, pluvial and
coastal flooding.
21

Secondary impacts
 Understanding and dealing with the downstream
impacts of climate change.
For example the impact of
mass migration and
changing demands for
water and sanitation on
infrastructure networks,
Social and economic
aspects must also be
considered.
22

 The professional institutions believe that the role
of the engineer in combating the damaging impact
of the construction industry on the environment
must be promoted strongly .
 The scientific evidence that climate change is a
reality is overwhelming and our understanding of
the potentially catastrophic nature of its effects is
increasingly clear.
 Governments should look for solutions turning to
engineers to provide them.
The Role of the Engineer
23

Sustainable Development
What is Sustainable Development?
 World Commission on Environment Development, (WCED
1987) defines sustainable development as ‘development that
meets the needs of the present without compromising the
ability of future generations to meet their own needs’.
 Foster & Partners have said that ‘Sustainable design creates
buildings which are energy efficient, healthy, comfortable,
flexible in use and designed for long life’.
 The UK Government has gone further and has stated that
‘Sustainable development means a better quality of life now
and for generations to come ...’ with the aim to ‘avoid using
resources faster than the planet can replenish them …’ and to
join up ‘economic, social and environmental goals’.
24

Sustainable construction should include the following features:
 Use only of those raw materials of which there are ample reserves, in
the ground or recycled from previous use, obtaining and processing
them without excessive environmental impact.
 Economical use of energy in the process of construction – only use
what you need to use.
 Durability or versatility in structures so that they can serve their
purpose effectively for 100 years or more, or where their life is
necessarily shorter, as an element within a long-term land use plan.
 Adaptability, so that elements of the structure can be converted or
extended to accommodate future changes in use and technology.
 Ease of demolition, when the structure finally becomes redundant, in a
manner in which materials can be recycled and the site re-used or
returned to a semi-natural state. Where massive construction occurs
which cannot be demolished i.e. dams or break waters, its ultimate
existence as a stable landform should be anticipated.
25

 Sustainable Development is founded upon the concept of the 3 Pillars
of Sustainability - a truly sustainable development addresses each of
these areas and seeks to reconcile their differing priorities and
concerns:
To what extent these 3 pillars are truly reconcilable? Are we fooling
ourselves into thinking that ‘development’ can ever be sustainable?
26

Measuring Sustainability
 How do we know when we are operating in a sustainable
manner? How do we know if a construction project is sustainable
or not?
 By the 1980’s it was recognised by some that nationally (or even
internationally) agreed measurement systems and benchmarks
were required to enable the sustainability of development to be
undertaken.
 These measures would need to be holistic in their approach.
They would need to consider all relevant Environmental, Social
and Economic aspects of construction.
 This lead to the development of a number of Environmental
Assessment Methods including BREEAM, CEEQUAL, LEED,
GreenStar etc.
27

Measuring Sustainability
 However in large parts of the world, construction
and development still occurs without any reference
to wider sustainability issues and with little regard
for the effect it may have on the local environment.
 The challenge you face as civil engineers is to
‘direct the great sources of power in Nature for the
use and convenience of man, whilst making best
use of scarce resources in care for the environment
and in the interests of public health and safety’
(I.C.E. Members Guide).
28

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Construction_Impact_and_Sustainability_p.pptx

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