By: Ella L.
New York, Shanghai, Hong Kong, Lagos— all of these cities lie on geographical structures called river deltas. A delta is an area of land where a river flows into a lake or ocean. Cities spring up around these river deltas because of their easy access to bodies of water for travel and trade. However, these delta cities typically have a low altitude, making them extremely susceptible to rising sea levels. These hubs are typically massive urban areas, meaning they have high and dense populations. It is estimated that they are home to approximately 339 million people worldwide, or about 10 million people more than the population of the entire United States. The Yangtze Delta area in China is one of the largest megalopolises; it is the home of 115 million people. All of these citizens are at risk of serious harm or displacement because of rising sea levels, therefore solutions must be explored immediately.
There are many reasons why these areas are especially affected by rising water, in addition to their low elevation. Cities use up a lot of energy and fossil fuels for cars, heat, etc, which leads to rising temperatures over time. These increasingly high temperatures can help cause extreme weather events, such as hurricanes and tropical storms, which then damage flooding infrastructure. In a study conducted on the Pearl River Delta (PRD), which includes cities such as Hong Kong and Guangzhou, scientists discovered temperatures in the PRD province have been rising by .3 degree celsius on average over periods of 10 years. They also discovered this province has been increasingly damaged by typhoons and other storms, causing the deaths of 73 people and the loss of 15.43 billion yuan (2.4 billion USD) in 2008 alone.
The best solutions for the dangers delta cities face (flooding, storms, etc) include preventative strategies. For example, stricter regulations of fossil fuels and major corporations can help reduce the amount of greenhouse gas emissions that we are releasing into the atmosphere, therefore curbing the acceleration of global warming and rising seas. Coping solutions are also effective, such as carbon sequestration, a process of capturing and storing carbon dioxide to reduce atmospheric levels of CO2. This process is included in the Paris agreement, which outlines a goal of 10 billion tons a year removed by 2050. Wetland restoration could also be beneficial to delta cities. Wetlands and swamps exist closer to the shores of a delta, and they act as a buffer to absorb precipitation and storm surges. Restoring these lands could act as a natural prevention tool for flooding. However, coping solutions will only do so much on their own. Coping solutions aim to eradicate the symptoms of climate change, not the root problem. For example, carbon sequestration stores carbon dioxide already in the atmosphere, but it does not prevent future carbon emissions. If we want to end the climate crisis, we need to use strategies that both alleviate negative impacts of climate change and stop it at its root.
Ameliorated urban planning can also help reduce the environmental dangers delta cities face. Poor infrastructure and storm management greatly contributes to rising water levels, so investing city funds into flood prevention infrastructure is imperative to reducing property damage and deaths during extreme weather events. Specific infrastructure improvements include building stormwater pumps and upgrading sewage systems, or using beaches as a natural barrier for rising water. Chicago has its own elected Water Reclamation Board, and you can help influence Chicago water infrastructure policy by voting for candidates willing to push for more aggressive green policies (next election in 2022). Urban gardens and agriculture can also help reduce rising greenhouse gas emissions , especially CO2, within cities. Urban horticulture and agriculture can alleviate the environmental stress on delta cities by mitigating the possibility of water-raising storms. Research has shown that these gardens can also promote urban food security and stress on rural farmland. Examples of urban agriculture include green roofs, home gardens, urban forests and parks, and more. Individuals can take action to protect delta cities by lowering their carbon footprint, voting for candidates with climate action plans, and learning about their city’s flood risk and how to prepare for flooding. The threat of rising sea levels puts the livelihoods of millions of delta city residents at risk, which is why world governments must take swift and decisive action now.
Discussion Questions:
What measures should world governments take to help delta megacities, and how can they coordinate their efforts to be more efficient?
Should local governments take the lead in alleviating these issues, or should national/federal governments take charge?