Sea level rise may threaten far more people than originally estimated. It turns out that more people live close to the sea coast than previous studies found, which means that sea level rise is set to drastically impact the lives of far more people than expected.
In this latest study, the researchers used several global gridded datasets. They first created a geographic zoning in relation to the elevation and proximity to the coast. This was then used to study the factors included in the study, which were grouped into five clusters: climate, population, agriculture, economy and impact on the environment. For the factors with temporal extent, the researchers also assessed their development over a time period of 1900 to 2050.
By using increased resolution datasets, the researchers estimated that 1.9 billion inhabitants, or 28 percent of the world's total population, live closer than 100 km from the coast in areas less than 100 meters above the present sea level.
This is particularly important to note. By 2050, the amount of people in that zone is predicted to increase to 2.4 billion, while population living lower than 5 meters will reach 500 million people. Many of these people, therefore, need to adapt their livelihoods to the changing climate.
While population and wealth concentrate by the sea, food must be grown further and further away from where people live. Highlands and mountain areas are increasingly important from a food production point of view but also vulnerable to changes in climate.
In addition to these findings, the researchers also discovered that cropland and pasture areas have grown most in areas outside population hotspots, and decreased in coastal areas. This will most likely continue in the future. They also found that even though people and wealth continue to accumulate in coastal proximity, their growth is even faster in inland and mountainous areas, which contradicts existing studies.
So what does this all mean? As sea levels rise, it will be important to take precautions in order to limit the effects of this rise on coastal population. Because so many people live on the coast, they will have to learn to adapt their lives to these rising sea levels, which may include more flood-resistant infrastructure and evacuations when there's an incoming severe storm.
