Rising Threat: 200 Million at Risk From Faster Climate Impacts

Sea levels around the African coast have risen 73% between 2009 and 2024, largely due to the 2023-24 El Niño event, putting more than 200 million coastal residents at risk.

Sea Level Rise Accelerated by El Niño

From 2009 to 2024, the sea level around the African continent rose significantly, with the 2023-24 El Niño playing a major role. The warming trend accounted for 2.3 centimeters (0.9 inch) of global sea level rise in that two-year span, representing 19% of the total increase observed over the 32-year satellite record since 1993.

The largest impact was observed around Africa, specifically in the western Indian Ocean and eastern central Atlantic Ocean. Researchers analyzed sea level rise using satellite data, computer models, and statistical methods, finding that over 70% of the increase resulted from stored ocean heat – almost four times greater than usual during the El Niño.

Rising Rates and Historical Shifts

While sea levels have been rising for decades globally due to rising global temperatures, the rate of increase is accelerating. The rate of 0.06 inches per year during much of the 20th century more than doubled to 0.14 inches per year from 2006 to 2015.

A marked shift in African sea levels occurred in 2009, with the rate of rise increasing from 2.7 millimeters (0.11 inches) per year to 4.7 mm (0.18 in) per year. The 2023-24 El Niño contributed to 27 mm (1.06 in) of rise, 41% greater than the previous El Niño event in 1997-98, which saw a rise of 19.2 mm (0.76 in). A typical rise is between 10 to 20 mm (0.39 to 0.79 in).

Impact on Coastal Communities

Africa’s extensive coastline, stretching approximately 18,950 miles (30,500 km), is particularly vulnerable. The oceans surrounding the continent are warming and rising faster than the global average, threatening over 200 million coastal residents and critical infrastructure in cities like Lagos and Dar es Salaam.

These Nigerian and Tanzanian metropolises are the largest population centers in West and East Africa, respectively. The study highlighted the danger to monitoring and adaptation measures, especially considering the 38 coastal countries on the continent rely on the ocean for food and economic security.

Researchers are working to differentiate between long-term warming trends driven by the burning of fossil fuels and short-term weather patterns like El Niño. They found that Africa’s low-lying deltas and small island states are most at risk due to the combined effects of flooding, subsidence, and declining ocean productivity.

Mitigation and Adaptation Strategies

Scientific studies on climate change can inform mitigation planning. While sea walls and other barriers may offer protection, managed retreat from coastal areas is also being considered.

Even eliminating pollution today may not halt rising waters, as heat already trapped within the ocean is a primary driver of sea level rise in Greenland and Antarctica. At least another 8 to 20 inches of sea level rise is expected by 2100 due to existing heat-trapping pollution in the atmosphere.

Addressing this issue requires decisive action, including supporting politicians who push for climate action and choosing to buy from companies that prioritize environmentally conscious decisions, such as embracing the circular economy and using sustainable packaging.