The melting of glaciers and land-based ice caps and the expansion of the oceans as a result of rising temperatures is one of the most severe consequences of human climate change. Since this effect has been observed, it is unlike other projected impacts of climate change.
Sea levels are rising, and data suggests that the pace of rising has accelerated recently and will continue to accelerate in the future. As seen in Figure 1, the average increase in sea level between 1993 and 2013 is shown.
An Increasing Concern
According to research just released by a team of experts, the rate of sea-level increase in the 20th century was more significant than it has been in 2,800 years. Globally, sea levels have risen by over 3 inches in the last two decades, and they are rising at a rate of around 1/8 inch each year.
Rather than saltwater thermal expansion, Melting land ice is to blame for a more significant portion of the recent sea-level increase. The ice melt problem is compounded by the fact that it can be accelerated by positive feedback.
Since snow-covered ice has a high albedo (the measure of how much light is reflected from an object), less heat is absorbed, and more is reflected.
In the United States, Coastal Resilience
Several coastal cities in the United States have initiated preparations to lessen the impact of rising sea levels. The “100-year flood zone” and the “500-year flood zone” of New York City, with annual flooding chances of 1 percent and 0.2 percent, respectively, are predicted to grow.
A map of New York City shows predicted flood zones based on a worldwide sea-level rise prediction of 2.5 feet by 2050, shown in Figure 2. The city established a thorough resilience strategy in response to the flood analysis and Sandy’s devastation.
Coastal Resilience in the World
The threat of rising sea levels is becoming a concern for cities worldwide. As in the United States, coastal cities in Australia confront the threat of tidal flooding, non-tropical storm flooding, and tropical cyclone storm surges.
Compared to the United States, Australian states and municipalities enjoy much control over their policies. Australia’s states and local governments have been given guidelines under a climate resilience and adaptation strategy developed by the country’s federal government.
Increasing Sea Levels and Coastal Flooding
Sea levels might rise more than half a meter by 2050 in 800 million people’s cities. Many coastal areas worldwide already face the threat of sea-level rise and coastal flooding, which may engulf entire neighborhoods, put people at risk, and wreak havoc on economies.
Many of the world’s cities will suffer an enormous threat from rising seas and coastal flooding by mid-century if the world does not adhere to the Paris Agreement’s aim of cutting carbon emissions and limiting global average temperature rise to 1.5oC.
Flooding and Storm Surges Threaten Cities
Climate risk in a city is exacerbated by socioeconomic and built environment factors, even if its topography places it at a greater danger of sea-level rise and coastal flooding, such as low-lying delta communities in typhoon and hurricane zones.
According to the New York Times, real estate in New York City’s floodplains, which includes some of the world’s most valuable homes, is estimated to be worth $129 billion.
Holding Back the Tides
It’s possible that the worst-case climate scenarios won’t materialize if emissions are reduced following the Paris Agreement. Still, sea-level rise and coastal flooding will only worsen anyway.
Despite the devastation caused by Hurricane Sandy, the natural disaster acted as a sobering reminder of New York City’s fragility and the need to keep the city secure for its economy.
“As a result of Hurricane Irma, city officials enlisted the help of climate change specialists from the academic community, private industry, and regional government agencies to improve city policies and strategies to decrease urban climate risk.