Coastal Development

Coastal Development refers to the development and evolution of coastal areas. Historically, coastal areas are popular locations for residence and economic development; mostly because they are are some of the most productive and biologically diverse on the planet and are good locations for trade. Since the 1950's, coastal populations on every continent have grown very rapidly as a result of global trade flourishing in coastal areas.¹ Currently, more than fifty percent of the world's population lives within forty miles of a coast, and demographic trends suggest that coastal populations are rapidly increasingly. ²By the year 2025, coastal populations are expected to account for 75% of the total world population. Some 53% of the total US population lives on the 17% of land in the coastal zone, and these areas become more crowded every year.³ ⁴

There are more than 3,000 cities in the low elevation coastal zones around the world. Of these cities, almost 65 percent are in developing regions. Asia alone accounts for more than half of the most vulnerable cities, followed by Latin America and the Caribbean (27 per cent) and Africa (15 per cent). In the developed world (including Japan), 35 of the 40 largest cities are either coastal or situated along a river bank. Almost one-fifth of all cities in North America are in low elevation coastal zones.⁵Many experts argue that cities will have to cope with almost all of the population growth to come in the next two decades, and much of this increase will occur in coastal urban centers.⁶

Coastal zones are highly vulnerable to climate change. Rising sea levels and the potential for stronger maritime storms pose an increasing threat to coastal cities and communities, and infrastructure. Key concerns are flooding, land loss, and implications for water resources.

Sea level rise and coastal storms

The expected continuation of rapid population growth in coastal areas will increase the impact of coastal climate change. Recent climatic trends, which are only a fraction of the magnitude of predicted changes in the coming centuries, have already triggered signiﬁcant responses in the Earth’s biological systems. As these changes continue, the risks of serious degradation of marine ecosystems increase, with far-reaching consequences for human health and welfare.⁷

Climate change is leading to higher sea levels. In the 20th century, sea levels rose by an estimated 17 centimetres, and global mean projections for sea level rise between 1990 and 2080 range from 22 centimetres to 34 centimetres.⁸ Rising sea levels are already submerging low-lying islands, eroding beaches, converting wetlands to open water, exacerbating coastal flooding, and increasing the salinity of estuaries and freshwater aquifers.⁹ The projected sea level rises could displace tens of millions of people in low-lying areas, such as the Ganges and the Nile deltas, and could threaten the very existence of small island states. Cities like Mumbai, Shanghai, Miami, New York City, Alexandria, and New Orleans are very likely be most exposed to surge-induced flooding.¹⁰

Climate change is also causing an increase in hurricane wind speeds, storm surge levels and more extreme wave heights, both inside and outside of the tropics. The power and frequency of Atlantic hurricanes, for example, have increased substantially in recent decades.¹¹ The storms and hurricanes occur as a result of the rise of sea surface temperatures in hurricane formation regions. They often cause high rates of death and injuries, as well as severe property, infrastructure and agricultural damage. ¹²

Coasts are also under under increasing threat of erosion from climate change and sea level rise, an effect which will be exacerbated by ever increasing human-induced pressures, like removal of coastal vegetation, agricultural development and other human activities.¹³

Impacts on coastal development

The impact of climate change on coastal areas will have consequences for water security, agriculture, fisheries, health, and tourism. The growing population density and related development activities in coastal areas already pressure the fragile balance of natural processes and human activies, and increase vulnerability to water-related impacts of climate change.¹⁴

Infrastructure damage

Industries and settlements located in coastal areas are very vulnerable to extreme weather events. An increase of such events as a result of climate change, is like to cause significant damage related costs, mainly since commercial development is increasing rapidly in coastal zones around the world. In the US in recent years, 40 percent of new commercial development and 46 percent of new residential development happened near the coast.¹⁵ In some areas, damage costs due to an increase in sea level have been estimated. For example, in Poland, estimated damage costs due to a possible rise in sea level of 1 meter by 2100 are US$30 billion, due to impacts on urban areas, sewers, ports and other infrastructure.¹⁶

Water quality

In many cases, water quality is likely to degrade, either as a result of the increased influx of sediments and pollutants with higher runoff, or because of decreased flushing and higher salinity levels with reduced stream flows. Increased salinity can threaten water quality for residential users and may also affect crops which are sensitive to increased salinity.¹⁷

Coastal agriculture

In addition to ncreased salinity, coastal agriculture is likely to be affected increasingly by storm damages and floodings. The coastal lowlands potentially affected by climate change include about one third of the world croplands; and many coastal lowlands, especially in the developing world, have limited or no human-built protection against impacts from sea level rise or storms. Brackish-water agriculture, including fish and shrimp ponds excavated in former mangrove agreas, are especially sensitive.¹⁸

Fisheries

The impact of climate change on fisheries are likely to vary in different locations. In many coastal areas, fish stocks have already decreased as a result of factors such as intensive fishing, coral bleaching, and acquatic pollution. Degradation of wetlands, which are spawning grounds for many commercially important fisheries, has also had a negative impact.¹⁹ Climate change effects impacting fish stocks include higher water temperatures and increased low-oxigent conditions. These factors can cause a change in types and size of species, species shift to cooler waters, and decline or increase of total amount of fish in an area. Fisheries communities are likely to feel impacts of climate change through changes in capture, production and marketing costs, changes in sales prices, and possible increases in risks of damage or loss of infrastructure, fishing tools and housing. Fishery-dependent communities may also face increased vulnerability in terms of less stable livelihoods, decreases in availability or quality of fish for food, and safety risks due to fishing in harsher weather conditions and further from their landing sites.²⁰

Coastal tourism

Coastal communities whose economies are closely linked to water-related tourism are especially vulnerable to the water resource impacts of climate change. Some areas are likely to become less attractive due to phenomena such as coral bleaching and weather changes.²¹ In the Maldives, for example, tourism currently is the backbone of the economy. The islands’ attractions include white sandy beaches and multi-coloured coral formations spread amongst a total of 74 island resorts. Around 40% of all tourists to the Maldives come for diving. A relatively small temperature increase could cause coral bleaching, as well as increase the threat of subsequent flooding, which would most likely end the popularity of the country for tourists. http://www.wwf.org.uk/filelibrary/pd...nd_cc_full.pdf On top of this, 80% of all tourism takes place in coastal areas, with beaches and coral reefs amongst the most popular destinations.²²

Adaptation

The impacts of climatic events on coastal development depend on both changes in climate, and adaptation responses of societal systems. "An example of an adaptation strategy to prevent damage from climate change is shore protection (e.g., dikes, bulkheads, beach nourishment), which can prevent sea level rise from inundating low-lying coastal property, eroding beaches, or worsen flooding. If the costs or environmental impacts of shore protection are high compared with the property being protected, an alternative adaptation strategy would be a planned retreat, in which structures are relocated inland as shores retreat." ²³

In the US, most coastal states are taking climate change adaptation measures. They are placing sand onto their beaches to offset shore erosion; and have adopted policies to ensure that beaches, dunes, or wetlands are able to migrate inland as sea level rises. Some states prohibit new houses in areas likely to be eroded in the next 30-60 years.²⁴

Governments in many developing countries lack the means and capacity to create and implement adequate adaptation strategies for coastal effects of climate change. The lack of access by governments to sufficient budget, capacity, and scientific data, in combination with the often large scale migration to the coastal areas, increases the vulnerability of coastal populations in these countries.²⁵In a recent report, the United Nations Convention on Climate Change (UNFCCC) highlighted the need for the international community to assist developing countries in their adaptation efforts: "Because of the speed at which change is happening due to global temperature rise, it is urgent that the vulnerability of developing countries to climate change is reduced and their capacity to adapt is increased and national adaptation plans are implemented. "²⁶