Climate change impacts on engineering infrastructure and water resources

Risks of Climate Change

THE RISK OF CLIMATE CHANGE: IMPLICATIONS FOR ARCHITECTS AND ENGINEERS

Climate Change Impacts on Engineering Infrastructure

Key Impacts on Water and Resources

Risk Management Analysis Coping Methods Possibility And Probability

Theories

Recommendations And Guidelines For The Vulnerability Of Climate

Change Impacts Using Risk Management Methods And Analysis

THE RISK OF CLIMATE CHANGE: IMPLICATIONS FOR ARCHITECTS AND ENGINEERS

This work examines climate change in relation to impacts upon infrastructure, utilities, and water in relation to the affects from projected sea level rise, flooding, and other related impacts expected to result from climate change. This work also reviews models used for risk assessment and analysis and examines their usefulness and the associated limitations with these models. Knowledge and expertise is growing in the risk-assessment and analysis field of study and reliable models are being developed although the primary effective and appropriate use for the majority of these models is on regional or local scale.

THE RISK OF CLIMATE CHANGE: IMPLICATIONS FOR ARCHITECTS AND ENGINEERS

OBJECTIVE

The objective of this work is to examine the architectural and engineering identification of the vulnerability of climate change risks in relation to engineering design and infrastructure planning. This work will apply risk management methods in this area.

INTRODUCTION

Adaptation is the word that Australia has applied to the coming problems and complications associated with climate change and building structures in terms of architecture and engineering design in its National Climate Change and Adaptation Framework report. While the debate continues as to whether climate change is in reality occurring, the change in the climate, continues and at a rate much faster than scientists previously believed the change would proceed according to their initial reports. A September 10th report on ABC News website this year related that during the period between September 3 through September 9-69,000 square miles of artic ice disappeared, roughly the size of the Sunshine State..." Or the state of Florida in the Southern United States. The report states that the melting is at an unprecedented rate and that "...ice researchers worry that the Artic is on track to be completely ice-free much earlier than pervious research and climate models have suggested." (Sandell, 2007) Weather patterns, according to Robert Correll, scientist and chair for the Artic Climate Impact Assessment, are shifting and will continue to shift "in ways that we are just beginning to understand." (Sandell, 2007) The risks because of the rising sea levels resulting from melting in the artic are being forecast in many places of the world. According to an ABC News report September 9th of this year, the Jakobshavn glacier and ice fjord at Ilulissat are reported by scientists to be "pouring out some 20 million tons of frozen water into the ocean every day." (Blakemore, 2007) A recent Science and Technology report published by the University of Maryland states that: "A first of its kind study by the University of Maryland, Tufts and Boston Universities demonstrates that in coming decades, sea level rise, changes in rainfall and other effects of climate change will have major, costly impacts on infrastructure systems of cities around the world." (University of Maryland, 2005)

I. CLIMATE CHANGE IMPACTS ON ENGINEERING INFRASTRUCTURE

There will be substantial impact upon structural engineering and architectural designs including homes, businesses, bridges, dam, and other structures worldwide due to climate change. Australia's "National Climate Change Adaptation Framework" states specifically that: "Infrastructure such as buildings, roads, bridges, railways and ports are designed for a life of 20-50 years. Dams can be designed for a 100 years life. Planning decisions for development and the replacement or refurbishment of long-lived infrastructure need to take account of the different climate in the future including higher temperatures and changes to precipitation, water tables and humidity." (nd) The exposure of people and infrastructure to affects of climate change are likely to increase, due to the increase in urbanization in areas along the coast and urban expansion in regional areas. (National Climate Change Adaptation Framework, nd; paraphrased) Variables that have been identified important for consideration in relation to climate change include: (1) extreme maximum temperature and length of hot spells; (2) annual rainfall; (3) extreme daily rainfall, influencing flood levels; (4) available moisture, which is influenced by changes to evaporation rates and levels of rainfall; (5) average relative humidity; (6) variation in wet and dry spells, affecting water tables and surface and subsoil inundation cycles; (7) intensity of extreme winds; (8) fire-weather frequency and intensity; (9) solar radiation levels and exposure; and (10) sea-level rise. (Climate Change and Infrastructure: Planning Ahead, 2005) The following chart lists the infrastructure type and the climate change impacts expected to affect each of the infrastructures listed.

Climate Change Impacts

Source: Climate Change and Infrastructure: Planning Ahead (2005)

Specific high risks associated with the 'high' climate change scenario for the year 2030 include the following risks and to the sectors as listed in the following figure.

Sector and High Risks in Climate Change

Sector

High Risks

Water Storm water drainage and flooding damage

Bushfire damage to catchments and storage

Power Increase in demand-pressure shortages

Substation flooding

Telecommunications Flooding of exchanges, access holes and underground pits

Transport Bridge degradation

Storm impacts on ports and coastal infrastructure

Buildings Degradation and failure of foundations due to changes in soil moisture

Increased storm and flood damage

Coastal storm surges and flooding

Increased bushfire damage

Source: Climate Change and Infrastructure: Planning Ahead (2005)

According to the work entitled: "Climate Change and Infrastructure: Planning Ahead" the following will be the threats to the sectors listed:

Water

Climate change is likely to result in drier conditions for most regions. However, extreme rainfall events are likely to increase in frequency and intensity.

An increasing frequency of extreme daily rainfall events would affect the capacity and maintenance of storm water, drainage and sewer infrastructure. Significant damage costs and environmental spills are likely if these water systems are unable to cope with major downpours.

Increased risk of major bushfires in the catchments of dams and reservoirs will threaten water quality and availability.

Due to drier conditions, increased ground movement and changes in groundwater could accelerate degradation of materials and structural integrity of water supply, sewer and stormwater pipelines.

Lower rainfall is likely to lead to water shortages, exacerbated by higher temperatures and increased demand from a growing population.

Energy

Increased frequency and intensity of extreme storm events may damage electricity transmission infrastructure and service. Increased wind and lightning could also damage transmission lines and structures. Extreme rainfall events could flood power substations. More storm activity would increase the cost of power and infrastructure maintenance and lead to more, and longer, blackouts and disruption of services.

Coastal and offshore gas, oil and electricity infrastructure is at risk of significant damage and increased shut-down periods from increases in storm surge, wind, flooding and wave events. Sea level rise would worsen these impacts.

Increased ground movement and changes in groundwater are likely to accelerate degradation of power generation and refinery plant foundations, as well as of transmission lines, gas and oil pipelines.

Extreme heatwave events are likely to increase in frequency, generating an increase in the peak demand for electricity for air conditioning.

The anticipated decrease in annual rainfall may reduce the power supply capacity of hydroelectric dams and the water supply necessary for cooling of coal-fired power stations for power generation.

Telecommunications

Increased frequency and intensity of extreme wind, lightning and bushfires may cause significant damage to above-ground transmission lines and associated infrastructure.

Downpours will affect access holes, pits and other underground telecommunications facilities.

Increased storm activity may result in a significant rise in the cost of telecommunications supply and infrastructure maintenance associated with increased frequency and length of network outages and disruption of communication services.

Transport

Increased frequency and severity of extreme rainfall events may cause significant flood damage to road, rail, bridge, airport, port and, especially, tunnel infrastructure. Rail, bridges, airports and ports are susceptible to extreme winds. Ports and coastal infrastructure are particularly at risk from storm surges; sea level rise will add to the problem.

A rise in the frequency of lightning strikes would affect rail operations. The projected increase in storm activity may increase the cost of transport infrastructure maintenance and replacement.

Increased ground movement and changes in groundwater would accelerate degradation of materials, structures and foundations of transport infrastructure. The result would be reduction in life expectancy, increased maintenance costs and potential structural failure during extreme events.

Increased temperature and solar radiation could reduce the life of asphalt on road surfaces and airport tarmacs. Higher temperatures may stress steel in bridges and rail tracks through expansion and increased movement.

Sea level rise may affect tunnels close to the coast through increased tidal and salt gradients, ground water pressure and corrosion of materials.

Building

Buildings will be affected by increased frequency and intensity of extreme rainfall, wind and lightning. Coastal buildings and facilities will be particularly at risk from storm surges exacerbated by higher sea levels. The predicted increase in storm activity could raise the cost of public and private building maintenance and replacement.

Increases in bushfire frequency and intensity have the potential to increase rates of damage to buildings and structures, especially those in non-urban areas.

Drier conditions may lead to increased ground movement and changes in groundwater. Higher temperatures and more solar radiation could amplify degradation of materials.

II. KEY IMPACTS ON WATER SUPPLY AND RESOURCES

Key impacts stated for case studies conducted in England list sea flooding of saltwater into aquifers may be a problem in some areas. Stated specifically is: "The expected rise in sea level as a result of climate change will increase the risk of the sea overtopping current defenses or encroaching on undefended land leading to flooding. Coastal flooding is also likely to increase in frequency due to predicted increases in storm frequency and intensity. The Environmental Agency Flood Map provides an indication of areas at risk of flooding from the sea....but this does not include increased risk of from climate change." (Adapting to Climate Change Impacts on Water Management: A Guide for Planners, 2006) Provisionary plans have been made in England to deal with the possible scenarios, which could occur in the future. Stated as the assessment risk checklist for impacts to water are the following: (1) Storm level rise; (2) Storm surges, extreme high water levels and tidal flooding; (3) Flash floods, slow onset flooding and fluvial flooding; (4) Groundwater rise flooding; (5) Land erosion/landslips/subsidence; (6) Storm damage; and (7) Water Shortage. (Adapting to Climate Change Impacts on Water Management: A Guide for Planners, 2006) Specific site development must necessarily answer the questions of "how the suitability of different adaptation responses will vary with: (1) Location - what adaptation measures are necessary or appropriate? (2) Size of development - What opportunities are there for requiring developers to deliver certain features in new developments? (3) Type and use of development - is the adaptation response suitable for residential, commercial, office, retail or industrial development? What level of risk can a development withstand? (4) Design life of the development - How long will the development be operational for?; (5) Type of developer - some developments may be more open to adaptation incorporation measures than others; (6) Potential synergies - response to other climate change related impacts; (7) Potential conflicts - between adaptation and/or mitigation options; and (8) Opportunities for 'no regrets' measures. (Adapting to Climate Change Impacts on Water Management: A Guide for Planners, 2006) The many risks and potentialities to be addressed in terms of water resources are listed in the following table specifically, the risks, adaptation measures and principles in pressure on water resources and addressing flood risks.

Menu of Adaptation Options to Respond to Water-Related Climate Change Impacts

Source: Adapting to Climate Change Impacts on Water Management: A Guide for Planners (2006)

Planning for climate change impacts on water are stated to include the following: (1) Water efficient fixtures and equipment within developments: A possibility exists for creation of a "valid planning condition or obligation to secure the installation of efficient fixtures and equipment within a new building, where a shortage has been identified and water conservations measures are essential for new developments to take place."; (2) Water meters to encourage demand management; (3) Water efficiency in gardens and communal places; and (4) Rainwater use systems and greywater use systems.(Ibid) Other measures include water conservation measures in terms of building regulations. Water reuse systems will be effective in addressing impacts of climate change. The rainwater reuse system will collect rainwater "from where it falls" and then treat, store, and distribute the water for use. Water will be collected within the boundaries of a property, which includes water draining from roofs and other surfaces including hardstanding ground and pervious paving. Correctly collected and stores the rainwater has many uses and has the potential to supply over 50% of domestic water use. Barriers to use include: (1) unproven cost to benefit ratio; (2) difficulties in operation and maintenance; (3) water quality standards and public health; (4) lack of guidance on system; and (5) lack of legislation in support of system. (Ibid) The cost for installation is stated to be "relatively low" but higher costs are associated with "retrofitting systems into buildings." (Ibid) Different buildings types are more suitable to certain methods of water efficiency as shown in the following list:

Method of Water Efficiency Type of Development

Dual and low flush cisterns Residential and commercial

Water efficient white goods;

washing machines and dishwashers Residential and Commercial

Low use showerheads and taps,

Pipe run and lagging Residential and Commercial

Urinal flushing controls Commercial

Rainwater and greywater systems Residential and commercial

III. RISK Management ANALYSIS COPING METHODS POSSIBILITY AND PROBABILITY THEORIES

In order to prepare for and cope with the potential problems that are certain to arise under the present climate change forecasts it has been necessary to create scenarios which are "commonly required in climate change impact, adaptation, and vulnerability assessments to provide alternative views of future conditions considered likely to influence a given system or activity." (Climate Change Risk and Vulnerability: Promoting an Efficient Adaptation Response in Australia, 2005) A scenario is defined as " a coherent, internally consistent, and plausible description of a possible future state of the world." (Climate Change Risk and Vulnerability: Promoting an Efficient Adaptation Response in Australia, 2005) Three types of scenarios exist which are those as follows: (1) Socioeconomic scenarios; (2) Environmental scenarios; and (3) Land-use and land-cover change scenarios; (4) sea-level rise scenarios; and (5) climate scenarios. (Climate Change Risk and Vulnerability: Promoting an Efficient Adaptation Response in Australia, 2005)

The work entitled: "Climate Change 2001: Working Group II: Impacts, Adaptation and Vulnerability" states in 2.2.1 Detection in Natural Systems that: "The cryosphere is very sensitive to climate change because of its proximity to melting. Consequently the size, extent and position of margins of various elements of the cryosphere (sea ice, river, and lake ice, snow cover, glaciers, ice cores and permafrost) are frequently used to indicate past climates and can serve as indicators of current climate change." (2001) However, it is stated that interpretation of climate change "resulting from changes in the cryosphere is seldom simple..." because many factors other than the climate are likely to affect glaciers and glacier dynamics. Land-use and land-cover change scenarios have been designed to estimate climate change and impacts to land. Land-use and land-cover data was evaluated by SAR and conclusions stated were that these data sets are quite often of "dubious quality." (Climate Change 2001: Working Group II) However, even with improvements insofar as internal consistently there are still "large regional differences in quality and coverage" which remain. The high-resolution global database "DISCover" is available and is derived "from satellite data and consists of useful land-cover classes." (Climate Change 2001: Working Group II) Land-use and land -- "cover change (LUC-LCC) involves various processes which are centric to climate change impacts estimation. LUC-LCC is stated to influence "carbon fluxes and GHG emissions [which] directly alters atmospheric composition and radiative forcing properties..." And "...changes land-surface characteristics and, indirectly, climatic processes." (Climate Change 2001: Working Group II) There have been many and various LUC-LCC scenarios developed with the focus generally being on issues that are local or regional with only a minimum of these with a global scope.

According to Climate Change 2001 Working Group I" there is an approach to evaluation that is "two-pronged." The modeling tools available to make provision of climate information is at the regional scale. Coupled AOGCMs are stated to be the fundamental models used for "...simulation of the climatic response in anthropogenic forcings" (Climate Change 2001 Working Group) Simultaneously limitations on resolution "pose severe constraints on the usefulness of AOGCM information, especially in regions characterized by complex physiographic settings." (Climate Change 2001 Working Group) To this end there have been three classes of regionalization techniques developed for enhancing the regional information of coupled AOGCMs, specifically: (1) high resolution; and (2) variable resolution time-slice AGCM experiments; (3) regional climate modeling; and (4) empirical/statistical and statistical/dynamical approaches." (Climate Change 2001 Working Group) Substantial progress has been made in regionalization methods as the techniques are better understood and development of a wide variety of modeling systems and methods has occurred as well as the application of techniques to a broader range of studies and regional settings also due to reduction in modeling biases. (Climate Change 2001 Working Group; paraphrased) It is stated that: "...regionalization techniques enhance some aspects of AOGCM regional information, such as the high resolution spatial detail of precipitation and temperature, and the statistics of daily precipitation events." (Ibid) AOGCM information is the 'starting point' for application of all regionalization techniques, therefore the AOGCM must simulate the circulation features associated with climate change that affect regional climates.

There is an indication of biases in the simulation of AOGCM on the sub-continental scale in simulations of regional and seasonal averaged surface climate variables although this is improved generally as compared to the prior generation models. The implication is stated for "increased confidence in simulated climatic changes." (Climate Change 2001 Working Group) Analysis on a regional scale of the AOGCM transient simulations, which extend to 2100, conducted for various scenarios of GHG increase and sulphate aerosol effects, and with a number of modeling systems have indicated that "the average climatic changes for the late decades of the 21st century compared to present day climate vary substantially across regions and models." (Climate Change 2001 Working Group) Stated to be the main source of uncertainty in the changes that were simulated linked with inter-modal range of changes, with inter-scenario and intra-ensemble range of simulated changes being less pronounced." (Climate Change 2001 Working Group) However, "common patterns of sub-continental scale climatic changes are emerging, and thus providing increased confidence in the simulation of these changes." (Ibid)

In relation to the 'predictability' of the climate system the Climate Change 2001: Working Group I: The Scientific Basis" states that the dynamics of the earth's atmosphere-ocean is "chaotic: its evolution is sensitive to small perturbations in initial conditions." The limitations placed on prediction of detail evolution of weather and attributing to the errors and uncertainties of the beginning conditions of forecasting weather is amplified throughout the entire forecast according to Palmer (2000). (Ibid; paraphrased) Detailed weather prediction is stated to have a limitation of approximately "two weeks." (Ibid) However, the slower variation of components of the climate system the ability to predict climate is not limited to this two-week time-scale. Reliable forecasting in "the presence of both initial condition and model uncertainty" is now possible in a repeating of the prediction "many times from different perturbed initial states and through use of different global models" which are called "multi-model, multi-initial-condition" and are the "optimal basis of probability forecasts." (Ibid) Estimation of anthropogenic climate change "does not depend on the initial state" the problem with prediction of climate change is in making an estimation of changes in the "probability distribution of climatic states as atmospheric composition is altered in some prescribed manner. Like the initial value problems...estimates of such changes to the probability distribution of climate states must be evaluated using ensemble prediction techniques." (Ibid) Some of the models used for climate change prediction impacts risks and assessment are those as follows:

1) Statistical Downscaling: This method is used in obtaining high-resolution climate or climate change information from relatively course-resolution global climate models. This model is appropriate for use when impact models only require small-scale data and to provide suitable observed data for deriving statistical relationships. (UNFCCC, 2005; paraphrased)

2) Dynamical Downscaling: This is a method for obtaining high-resolution climate or climate change information from relatively course-resolution global climate models. This model is appropriate when impact models require small-scale data. (UNFCCC, 2005; paraphrased)

3) Statistical DownScaling Model (SDSM): This is a software designed to implement statistical downscaling methods to produce high-resolution, monthly climate information from course-resolution climate model simulations. These model also uses weather generator methods to produce multiple realizations of synthetic daily weather sequences. SDSM can be used while impact assessments require small-scale climate scenarios, provided quality observational data and daily GCM outputs for large-scale variables are available. (UNFCCC, 2005; paraphrased)

4) MAGICC/SCENGEN: that software takes emissions scenarios for greenhouse gases, reactive gases and sulfur dioxide as input and gives global-mean temperature, sea level rise, and regional climate as output. MAGICC is a coupled gascycle/climate model. It has been used in all IPCC reports to produce projections of future global-mean temperature and sea level change, and the present version reproduces the results given in the IPCC Third Assessment Report (TAR). MAGICC can be used to extend results given in the IPCC TAR to other emissions scenarios. SCENGEN is a regionalization algorithm that uses a scaling method to produce climate and climate change information on a 5° latitude by 5° longitude grid. The regional results are based on results from 17 coupled atmosphere-ocean general circulation models (AOGCMs), which can be used individually or in any user-defined combination. This model can be used when future atmospheric composition, climate or sea level information is needed. (UNFCCC, 2005; paraphrased)

5) COSMIC2 (Country Specific Model for Intertemporal Climate Vers. 2): The COSMIC2 model provides climate-change impact modelers and policy analysts a flexible system that can produce a full range of dynamic country-specific climate-change scenarios. The need for this type of modeling capability was discussed at the IPCC Asia-Pacific Workshop on Integrated Assessment Models held in Tokyo in 1997. That Workshop aimed at improving communication between experts in a variety of disciplines and policy analysts/policy makers. One goal was to expand the use of integrated-assessment modeling for addressing the potential impacts of climate change in a way that better reflected the experiences of researchers from developing countries. These researchers (and others at universities around the world) may not have access to state-of-the-art transient (General Circulation Model) GCM simulations. The expense of running these supercomputer models limits their availability and ease of use. The COSMIC2 model helps remove this limitation. COSMIC2 can provide easy access to credible climate-change scenarios that are consistent with the state-of-the-art, fully coupled, transient ocean-atmosphere GCM simulations. Can be used for making estimations of country level climate change and the climate change scenarios can be used in impact, vulnerability and assessments. (UNFCCC, 2005)

6) PRECIS (Providing Regional Climates for Impact Studies) - The Hadley Centre regional climate modeling system: PRECIS is essentially a regional climate modeling system. It is based on the third generation of the Hadley Centre's regional climate model (HadRM3), together with user-friendly data processing and visualization interface. Its flexible design allows for applications in any region of the world. Like any other regional climate models, PRECIS is driven by boundary conditions simulated by General Circulation Models (GCMs). To facilitate the application, boundary conditions simulated by the Hadley Centre GCM experiments forced by four SRES marker scenarios are supplied with the software. Can be used to generate finer-resolution, physical consistent regional climate projects when General Circulation Model (GCM) outputs are not sufficient to provide regional details as required by V&An assessment. (UNFCCC, 2005)

7) Weather Generators: Weather generators are not, strictly speaking, downscaling techniques, but are often used in conjunction with the techniques outlined in this section. A weather generator is a statistical model used to generate realistic daily sequences of weather variables -- " precipitation, maximum and minimum temperature, humidity, etc. Such data are often referred to as synthetic data. Usually precipitation sequences are generated first, and other data sequences are derived using statistical relationships between these data and precipitation, with different relationships used for wet and dry days. Precipitation is divided into an occurrence process (i.e., whether the day is wet or dry) modeled as a Markov chain, and an amount process (the amount of precipitation on a wet day) sampled randomly from an appropriate distribution, such as a Gamma distribution. By using different random seeds, a large number of sequences can be generated, all of which have the same statistical properties as the original data used to calibrate the statistical model -- " akin to realizations from a set of parallel universes. This is a crucial factor in assessing uncertainties associated with the chaotic nature of daily weather variability. The SDSM software has a weather generator component. Can be used whenever impact models require small-scale data on a daily time scale, provided suitable observed data are available to derive the statistical relationships. (UNFCCC, 2005)

The work entitled: "Climate Change Models Predict the Future" relates that mathematically-based climate models have been developed by scientists and each model "uses different assumptions about the future to predict how atmospheric CO2 levels and temperatures will change." (nd) The variables in each model includes: (1) population growth rate; (2) economic development; (3) energy use; (4) efficiency of energy use; and (5) mix of energy technologies. (Climate Change Models Predict the Future, nd) The following graphic illustrates the results from three of the IPCC climate models in predictions beginning in 1990 and ending in 2100.

IPCC (Three Climate Models) 1990-2100

Source: (Climate Change Models Predict the Future,

The AIB model makes the assumption of "rapid economic growth and increased equity - the reduction of regional differences in per-person income. New and more efficient technologies are introduced in this model without reliance be placed heavily upon any single energy source. The A1F1 model is the same as A1B with the assumption of the continued use of fossil fuel-intensive technologies. The B1 model has the world rapidly moving from producer-consumer economy to a service and information economy. Reduction exists in use of raw materials and the emphasis is one "clean and efficient technologies and improved equity." (Climate Change Models Predict the Future, nd)

IV. RECOMMENDATIONS AND GUIDELINES FOR THE VULNERABILITY OF CLIMATE CHANGE IMPACTS USING RISK Management METHODS AND ANALYSIS

Because assessment of the risk of climate change requires a good knowledge of the possibilities of climate change and consequences resulting from climate change and because the uncertainties are based upon scenarios that may be believable but not viable, it is necessary that models constructed for climate change are conducted on a regional and local basis in order to make proper risk assessment and adaptation plans. Furthermore it is necessary that the models be used that allow for plenty of remodeling with slight changing of variables and conditions of the model because slight differences in data may result in large differences needed for planning adaptations. To this end it is necessary that those in decision-making positions conduct ongoing modeling of the possible impacts of climate change to a specific area or region. The field of probability modeling is gaining more knowledge and expertise however, at this point in time there is no global scale probability modeling that can be applied on a global basis as the impacts from climate change have so many potential variations according to region and location. Recommendations include constant updating of knowledge in this area to keep track of advances in technologies and applications for better prediction of climate change impact.