Study Shows That 8% of Earth’s Surface Could Submerge Within 20 Years

RIO DE JANEIRO, BRAZIL – By 2040, at least 8% of the Earth’s surface is expected to be submerged, according to a study published in Science magazine. The study suggests that about 12 million square kilometers of land are under threat, with an over-50% probability of this occurring, which would affect more than 635 million inhabitants.

According to researchers, the problem will be due to a geophysical phenomenon known as subsidence, caused by the sinking of land surface as a result of water, oil and gas extraction from underground. According to the studies, the most affected areas will be close to urban and irrigated sites, with high levels of water stress and high demand for water found underground, such as locations in Asia and North America.

“Subsidence permanently reduces the stock capacity of the aquifer system, causing cracks in the earth, damaging buildings and infrastructure, and increasing the likelihood and risk of flooding,” the researchers explain.

The demand for groundwater has already led to serious consequences for humankind – and should increase in coming decades. The world’s fastest sinking city is located in Iran: each year it sinks 25 centimeters due to irregular pumping. In Europe, the most impacted country is The Netherlands, where subsidence is responsible for placing 25% of the nation below sea level, which raises the risk of flooding.

In other continents, such as Africa, Australia and South America, the risks of subsidence are lower due to the depletion of groundwater.

The highest risks for the population are found in Asia (with 86% of the population potentially exposed to subsidence) and North America and Europe (both continents with 9% exposure). The results, according to researchers, show that 97% of the globally exposed population is concentrated in 30 countries – with India and China leading in terms of extension and exposed population.

This will be caused by climate change, according to researchers. “Throughout this century, global warming will have a serious impact on the world’s water resources, due to rising sea levels, increasingly frequent and severe flooding, as well as droughts and changes in rainfall value (rain versus snow), and an increase in evapotranspiration. Prolonged droughts will reduce groundwater supply and increase its depletion, intensifying subsidence,” the scientists explain.

This is not the first (nor the last) time that science has alerted to the impact of subsidence. In 2018, it was noted that Jakarta, the capital of Indonesia, had sunk 2.5 meters in ten years, and was expected to keep sinking 25 centimeters per year.