FACULTY OF ENGINEERING AND BUILT ENVIRONMENT DEPARTMENT OF CIVIL ENGINEERING AND STRUCTURE
KKKH4284 SUSTAINABLE URBAN DEVELOPMENT
TASK 6: GLOBAL WARMING
STUDENT’S NAME: MUHAMMAD IMRAN BIN MOHD JUNAIDI MATRIC NO.: A133239 LECTURER’S NAME: Prof. Ir. Dr. RIZA ATIQ ABDULLAH BIN O.K. RAHMAT
Climate change refers to the variation at a global or regional level over time. It describes the variability or average state of the atmosphere or average weather over time scales ranging from decades to millions of years. These variations may come from processes internal to the Earth, be driven by external forces (e.g. variations in sunlight intensity) or, most recently, be caused by human activities. Just as weather patterns change from day to day, the climate changes too. This occurs naturally, driven by internal and external factors. However not all changes are due to natural processes, as we humans have also exerted our influence, which is called anthropogenic climate change. Through widespread use of land, use of fossil fuels and the building of cities, we have changed our climate. The major technological and socioeconomic shift of the industrial era with reduced reliance on organic fuel, the accelerated uptake of fossil fuels, and broad scale deforestation, means we have contributed to the natural greenhouse effect. The key areas for concern are those related to variability and extremes, not simply changed average conditions. There is an accumulating body of evidence of observed impacts relating to regional changes, and that these are having fearful effects on the world around us. There are already people who have become climate refugees, and millions more are expected in the future. Temperatures across the globe are most certainly rising; the 1990s was the warmest decade in the last thousand years. Sea surface temperatures have increased 0.4-0.8째C (0.7-1.4째F) since the late 19 Century, and over the period 1961 to 2003, global ocean temperature has risen by 0.10째C (0.18째F) from the surface to a depth of 700 m.
SEA LEVEL RISING Although sea levels have been rising since the end of the last glaciation (nearly 11,000 years), the rate of rise has increased over the past 200 years as average global temperatures have increased. The rise is due to two factors, the freshwater being added to the oceans from ice melt in the cryosphere , and the thermal expansion of the oceans due to rises in sea temperature. The contribution from Antarctica melt water is uncertain, and there is a distinct possibility of surprises from this southern region. The floating ice shelves, notably the Wordie and Larsen A and B shelves, broke up very rapidly during the 1990s, after rapid regional warming. Climate, like other complex systems do not always vary in a smooth fashion, and sudden changes can occur over wide areas. Critical levels, or thresholds may be reached in a system whereupon drastic, and perhaps disastrous results occur. Threshold events in this case include the complete or partial shutdown of the ocean thermohaline circulatory system, disintegration and melting of Antarctica and Greenland Ice Sheets (the polar caps) , and major changes in the carbon cycle, due to biospheric effects (see the Snowball Earth scenario). Estimates for the 20th century show that global average sea level rose at a rate of about 1.7 mm per year. Satellite observations available since the early 1990s provide more accurate data with nearly global coverage. This decade-long satellite altimetry data set shows that since 1993, and shows rising at a rate of around 3 mm per year, significantly higher than the average during the previous half century. Global levels are projected to rise during the 21st century at a greater rate than during 1961 to 2003. Thermal expansion is projected to contribute more than half of the average rise, but land ice will lose mass increasingly rapidly as the century progresses. An important uncertainty relates to whether discharge of ice from the ice sheets will continue to increase as a consequence of accelerated ice flow, as has been observed in recent years. In particular, the Arctic is warming at a higher than global average, resulting in increasing surface melt from the Greenland Ice Sheet.
IMPACT OF SEA LEVEL RISE Rapid urbanization in low-lying coastal areas of both the developing and developed world is increasing population densities and the value of human-made assets exposed to coastal climatic extremes such as tropical cyclones. IPCC model based projections of the average annual number of people who would be flooded by coastal storm surges is estimated to increase several fold, creating 200 million climate refugees. This is based on what is called a â€˜mid-range scenarioâ€™ of a 40-cm sea-level rise by 2080, which is pretty conservative. The U.S. Environmental Protection Agency (EPA) notes that the sea level has risen 15 to 20 cm (6 to 8 inches) in the past 100 years, and it is predicted to continue another 50 centimeters (20 inches) over the next century (with some estimates as high as 90 centimeters, or 3 feet). The sea level is definitely rising, and it is jeopardizing rapidly growing coastal communities. Official decisions on evacuation of whole populations from some atolls in the Pacific Ocean have been taken or are being considered. For example, 980 people, the entire population of the Carteret Atoll, will need to be evacuated by 2015, and the island is destined to become history. A similar fate awaits the small nation of Tuvalu and Majuro in the Marshall Islands. The potential of damage to infrastructure in coastal areas from sea-level rise will be tens of billions US$ for individual countries like; Egypt, Poland, and Vietnam.
The first image above on the far left was taken on 12 August 1997 of a house at Floralton Beach, Florida. When Hurricane Frances came through on 8 September 2004 all vegetation and dune lines were wiped out (middle image). As a result, the house was directly exposed and completely destroyed when coastal surges from Hurricane Jeanne hit on 29 September 2004.
It is interesting to note that seventy one percent of annual United States disaster losses are the result of coastal storms. It is estimated that within 60 years, one out of every four of those structures will be destroyed and insurance costs will sky rocket. This is not surprising given that the narrow fringe comprising less than one fifth of the contiguous United States land area, accounts for over one half of the nation’s population and housing supply.
CLIMATE MITIGATION AND ADAPTATION Climate mitigation is any action taken to permanently eliminate or reduce the long-term risk and hazards of climate change to human life, property. The International Panel on Climate Change (IPCC) defines mitigation as: “An anthropogenic intervention to reduce the sources or enhance the sinks of greenhouse gases.” Climate Mitigation and Adaptation Climate adaptation refers to the ability of a system to adjust to climate change (including climate variability and extremes) to moderate potential damage, to take advantage of opportunities, or to cope with the consequences. The IPCC defines adaptation as the, “adjustment in natural or human systems to a new or changing environment. Adaptation to climate change refers to adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities. Various types of adaptation can be distinguished, including anticipatory and reactive adaptation, private and public adaptation, and autonomous and planned adaptation.” The terms “adaptation” and “mitigation” are two important terms that are fundamental in the climate change debate. The IPCC defined adaptation as adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderate harm or exploits beneficial opportunities. Similarly, Mitchell and Tanner (2006) defined adaptation as an understanding of how individuals, groups and natural systems can prepare for and respond to changes in climate or their environment. According to them, it is crucial to reducing vulnerability to climate change. While mitigation tackles the causes of climate change, adaptation tackles the effects of the phenomenon. The potential to adjust in order to minimize negative impact and maximize any benefits from changes in climate is known as adaptive capacity. A successful adaptation can reduce vulnerability by building on and strengthening existing coping strategies.
In general the more mitigation there is, the less will be the impacts to which we will have to adjust, and the less the risks for which we will have to try and prepare. Conversely, the greater the degree of preparatory adaptation, the less may be the impacts associated with any given degree of climate change. For people today, already feeling the impacts of past inaction in reducing greenhouse gas emissions, adaptation is not altogether passive, rather it is an active adjustment in response to new stimuli. However, our present age has proactive options (mitigation), and must also plan to live with the consequences (adaptation) of global warming. The idea that less mitigation means greater climatic change, and consequently requiring more adaptation is the basis for the urgency surrounding reductions in greenhouse gases. Climate mitigation and adaptation should not be seen as alternatives to each other, as they are not discrete activities but rather a combined set of actions in an overall strategy to reduce greenhouse gas emissions.
MITIGATION AND ADAPTATION STRATEGIES A suite of adaptation actions are identified for each section, ranging from low cost and easy to implement, to larger, more complex projects. Response strategies identified as primary actions represent the key projects that will help the city adapt to climate change. Supporting actions represent application of an adaptation lens to existing actions or generally lower cost/smaller scope activities. Where there are no primary actions to address a climate change, only a suite of supporting actions are introduced. No-regret actions are the focus â€“ those that build on existing plans and actions and provide community benefits regardless of the extent of climate change experienced. Each objective is achieved through a combination of different actions which act together. These portfolios of actions generally include measures from the following four categories: â€˘
modifying policies, plans, procedures, standards (e.g. by-laws, development plans, operating practices, codes);
building new or upgrading infrastructure;
improving community awareness and education; and
varying/diversifying existing actions (e.g. diversifying energy supplies, diversifying plantings).
The actions in the Strategy largely focus on areas where the City can take independent action. To this end we completed an early scan of suggested adaptation actions to ascertain whether they fell within the City’s jurisdiction/responsibility or not. Some actions signal necessary collaboration with the regional and provincial governments, and it is recognized that local adaptation is reliant on close ties and joint actions with other levels of government, neighbours, the private sector and community groups. Staff will continue to collaborate on projects and push for regional coordination on adaptation issues. Increase The Resilience Of The City Infrastructure And Assets To Coastal Flooding And Erosion Sea level rise adaptation options include protecting our coastlines with defenses, accommodating higher water levels by elevating infrastructure, avoiding flood prone areas by focusing development elsewhere, and retreating via land acquisition etc. Choosing among options is a complex task that starts with a clear risk assessment detailing the magnitude and frequency of coastal flooding, identifying vulnerabilities and quantifying potential damages and losses. The City endeavors to find solutions that minimize the financial, social and environmental impacts of future flooding while ensuring near-shore amenities, access, views and other benefits are maintained. A city-wide sea level adaptation response will provide high-level direction to navigate through the complex issues and make civic investments without creating undue hardships in the short term. While the risk assessment is being completed, the City’s interim flood construction levels need to be revised, and associated Flood-proofing policies amended to provide certainty. Policies will be revisited and updated upon completion of the City-wide sea level rise response strategy. Primary Action: Complete A Coastal Flood Risk Assessment And Develop A City-Wide Sea Level Rise Adaptation Response
Strategic planning for sea level rise is complex given the uncertainty associated with the rate of water level rise and changes in storm frequency, the environmental and financial implications of engineering solutions, and the long timeline for fundraising and implementing such unique capital projects. It took 30 years for the United Kingdom and the Netherlands to add new storm protection after a disastrous coastal storm in 1953. While we are not expecting observable impacts from sea level rise for some time, we need to start thinking about options now. A comprehensive risk assessment is a recognized best practice and first step toward planning actions to mitigate the risks posed by sea level rise. Continuing to coordinate with other municipalities regionally, with other levels of Government, and with partners will be integral to maintaining the economic vibrancy of the region. The flood risk assessment will include the following general phases of work: •
Phase 1: Flood hazard mapping/modeling
Phase 2: Vulnerability Assessment
Phase 3: Consequence Analysis
Phase 4: Risk Management Options/Trade-off Analysis Risk assessment outputs will support development of a city-wide sea level rise adaptation
response that will address new infrastructure needs, erosion protection considerations, land use regulation changes and plans for amenities such as beaches and the seawall.
Primary Ac tion: Update City Flood-proofing policies including Flood Construction Levels While numerous municipalities in the lower mainland maintain many kilometers of dikes, the City has relied on other tools such as flood construction levels (FCLs) and setbacks. City flood-
proofing policies establish these elevations and setbacks by flood prone area. The last amendment to the policies in 2007 flagged the need for future updates to incorporate new sea level rise information. The City encouraged an interim increase of 1m to existing FCLs while undertaking a study to apply guideline methodology to specific coastline types. Amending the flood-proofing policies will increase the flood resilience of new development and maintain the potential for a range of adaptation solutions in the future. Increasing the awareness of builders and developers with respect to flood-proofing methods and considerations will be an important complement to policy amendment. Supporting Actions: •
Continue to coordinate with other regional municipalities and other levels of government to ensure a regional approach to coastal flood management.
Leverage opportunities to evaluate strategic near-shore open space planning for inundation and containment areas and saltwater resilient plantings.
Initiate a flood-proofing awareness campaign among builders and developers.
Monitor low-lying storm sewer capacity and functionality and continue to add back-up power and storage tanks to existing stormwater pumps.
Monitor groundwater for increasing levels. Consider associated impacts in coastal development design.