Living with Water Trivia Quiz

Answer: Easier access to harbors

While rising sea levels theoretically might increase the depth of some harbours, allowing easier access for bigger ships, this would not be a devastating effect.

According to conservative estimates, sea levels will rise 0.5-1.0 m (1.5-3 ft) by 2100 because of melting glaciers and warming of the oceans. A growing number of scientists believe the increase will be more than double these figures. The implications are far-reaching, from the disappearance of small island states, permanent flooding of some low-lying coastal areas and increased flooding from storm surges to contamination of freshwater sources and reduced food supplies from loss of farmland.

A 2019 study by researchers at the University of Melbourne showed that both extreme wind levels and wave heights have been increasing significantly since 1985, which will intensify coastal flooding.

A 2018 report, "The Future We Don't Want" by the group C40 Cities, predicts that over 800 million people will be affected by coastal flooding by 2050. Low-lying cities in all parts of the world will be affected, among them Jakarta, Manila, Bangkok, Mumbai, Shanghai, Lagos, and New York to name just a few.

Answer: Pancake method

With more than two thirds of its land below sea level, the Netherlands has been preventing flooding and reclaiming land from the sea for over 2,000 years. In 1997, Amsterdam began reclaiming land from the ocean by creating a new artificial IJburg archipelago. Using a "pancake method", they have poured multiple layers of sand onto weak subsoil, allowing each to harden to sludge, and then covering them with the next "pancake" until the island reached two meters above the water level.

In 2002, residents began moving onto the islands which provide a mixture of low-rise single homes and mid-rise buildings. Also interspersed are "neighbourhoods" of floating houses constructed on buoyant concrete tubs.

The archipelago will house some 45,000 people when the last islands are completed by around 2026.

Answer: Nuclear-driven giant windmills

While giant nuclear-driven windmills are not yet in use, cities in different parts of the world are looking to a wide range of barrier technologies to hold back flooding from increasingly strong storm surges.

The port of Rotterdam in the Netherlands took six years to build a giant floodgate 22 m (72 ft) tall and 210 m (690 ft) long. The system, which became operational in 1997, allows ships to pass through when the gates are open. A supercomputer, which is continuously analysing weather and sea level data, automatically shuts the gates when water levels rise 3 m (close to 10 ft).

Venice, one of the most vulnerable European cities, has opted to go with retractable floodgates that stretch across the three inlets to their lagoon. Most of the time, the gates sit on the bottom of the seabed. When water levels rise to 110 cm (3.6 ft), compressed air is pumped into the gates raising the barriers. There is, however, growing concern that the system could quickly become obsolete as was designed for a sea rise level significantly lower than the worst case scenarios now being projected.

Some cities are introducing modular inflatable barriers to cope with temporary periods of storm surge. Most of these come in some form of relatively lightweight rolls to allow them to be transported and inflated with blowers.

Answer: Room for the River

High barriers alone do not provide a comprehensive response to the water challenges of the future. Instead of focusing exclusively on keeping the water out, The Dutch are now taking a "living with water" approach.

"Room for the River" is a program overseen by the Dutch Ministry for Infrastructure and Environment. Its solution to flood management is to enable rivers to expand more naturally during peak water periods. The agency is helping cities to introduce a wide range of measures to make this happen, such as pushing back dykes and deepening river beds to give rivers more room to expand. Some cities are creating secondary, high water channels to handle overflow; others are removing obstacles to allow water to move faster. Several are creating more open public spaces like outdoor parks where water can filter back into the ground during times of flooding. In some cases, these strategies involve moving houses and farms away from flood plains.

Answer: Settling or sudden sinking of land surface

Subsidence is the settling or sudden sinking of land's surface that occurs when groundwater is removed causing the soil to dry out and the resulting air pockets to compress and collapse. Part of the reason why New Orleans experienced such devastating flooding during Hurricane Katrina in 2005 and why it remains vulnerable to future storm surges is because of subsidence.

Before the arrival of French and Spanish settlers in the early 18th century, almost 100% of the land was above sea level. Over time, because of poorly designed drainage systems and artificial levees, the soil was deprived of groundwater that should have infiltrated and replenished the earth. Consequently, the area began to sink. Today, nearly half of New Orleans is at or below sea level. The article "How Humans Sank New Orleans" by Richard Campanella in "The Atlantic" provides a fascinating overview.

It was only after Hurricane Katrina that the Greater New Orleans Area (GNO) began to question seriously the wisdom of relying primarily on levees and pumping stormwater away from the city for protection. The GNO Urban Water Plan adopted in 2013 called for allowing as much rainwater as possible to flow naturally back into the soil through a wide range of measures, among them the creation of more open park lands, canals, roof gardens and water reservoir systems, and the development of rain gardens.

Answer: Impermeable sidewalks

As sea levels rise, flooding, particularly during storms, is becoming more frequent and reaching further inland. One of the exacerbating factors for many coastal cities is that dense urban development has interrupted the natural water absorption cycle. With so much land covered by buildings and impermeable streets and pavements, only about 20%-30% of storm runoff can flow into the ground or back into natural waterways.

China has started a "sponge cities" initiative to help improve water absorption. The somewhat optimistic goal is to have 80% of urban land able to capture, reuse or absorb 70% of storm runoff. Thirty pilot cities are implementing a range of strategies, such as replacing old impermeable pavements with porous materials and creating artificial wetlands, rain gardens and other features to absorb excess rainfall. They are also installing new drainage and storage systems.

Shanghai, the largest city to take up the challenge, is emphasising the creation of green rooftop gardens and set itself an initial goal of adding 400,000 squares metres or 40 hectares of roof gardens in the first year. New buildings must have a minimum of 50% of the roof covered by gardens.

Answer: Intensifying coastal development

Singapore, like many countries in South-east Asia, is extremely vulnerable to the adverse effects of rising sea levels. It has adopted a wide range of protective measures, from raising roads in low-lying areas and increasing the elevation of planned additions to their airport, to building a large storage tank and diversion canal complex.

Of particular concern is what rising seas will do to Singapore's water supply. The Marina Barrage, completed in 2008, serves both to relieve flooding in low-lying areas and forms Singapore's 15th reservoir for stocking fresh water. It has a catchment area of 10,000 acres. A new desalination plant scheduled for completion in 2020 will have the capacity to treat water both from the ocean and the Marina Reservoir.

Answer: Increasing salinity of the soil

Rising sea levels and flooding impact agriculture in several ways, from the loss of growing crops to the erosion of arable land and increased salinity of the soil. The latter is one of the most destructive.

Freshwater typically has a salinity level of 0.5 grams per thousand. Researchers studying the effects of 2016 and 2018 hurricanes on farmland in North Carolina in the USA have found levels of 2 to 3 grams per 1000 in surface ditches and up to 9 grams per 1000 in below ground samples.

Traditional staple crops like rice and sugar cane do not grow well in high saline conditions. Even moderate increases in salinity can result in a reduction of up to 20% in crop production. Delta countries like Bangladesh, Egypt, and Vietnam are among the countries most affected. Although some farmers are transitioning to aquaculture which can support increased salinity, this is not an option for more impoverished farmers, many of whom are migrating inland. Although researchers are working to produce more-salt-friendly varieties of rice, these are not available at the time of writing.

In 2014, the UNU Institute for Water, Environment and Health estimated that 62 million hectares were affected by salt intrusion, roughly 20% of the total irrigated land worldwide. The problem is not limited to the immediate coastal and delta areas. The transition zone, the zone where saltwater intrudes into freshwater in underground aquifers, appears to be moving further inland.

Answer: 2030

Low-lying island states, such as Kiribati, the Maldives, and the Marshall Islands would be among the hardest hit by rising sea levels. Some, like Kiribati with its average elevation of 1.8 m (6 ft) above sea level, could be submerged within the next century; however, many may be uninhabitable long before. A 2018 study on the Marshall Islands conducted by the US military predicts that the islands could be uninhabitable as early as 2030. With the increased frequency of flooding associated with rising sea levels, there may no longer be enough time between episodes for recovery from damage to infrastructure and contamination of freshwater resources.

Displacement is a looming problem for many of the islands. Kiribati has already reported that residents closest to the ocean are moving into the interior, putting a severe strain on local resources. Forced migration to other countries is a real possibility. The Kiribati government has adopted a "Migration with Dignity" policy to create opportunities for islanders to migrate and establish expatriate communities in countries like Fiji, New Zealand and Australia. It also provides training to raise educational and skills levels to make it easier for migrants to integrate into their new home countries.

The Maldives is taking a very different approach. The government there is working to relocate people from the smaller to the larger islands and building up artificial islands on some of the coral reefs. The first new island city, the City of Hope, is expected to be ready by 2023 and will have a 3 m (9.8 ft) wall surrounding it.

Answer: No

No, recent studies suggest that reaction time for sea level rise is much slower than for global temperatures. A 2018 paper published by climate scientists at Oregon State University in the USA predicts that the sea levels will continue to rise for up to a thousand years even if all carbon emissions halt entirely, mainly because carbon dioxide emissions will remain in the atmosphere for years to come. The primary author, Peter Clark, has suggested that we need to be planning far beyond 2100.

While we cannot stop the rising sea level, scientists believe we can change the rate of the increase. Scientists are showing there is a definite link between global warming and the rising sea levels. The Intergovernmental Project on Climate Change has suggested that sea levels will rise about 2.3 m (7.5 ft) for every degree increase in the global temperature. If humans manage to reduce carbon dioxide emissions, we may be able to slow the rate at which the sea level rises.