New York, 28 August 2024
A new UN brief outlines the current scientific understanding of sea-level rise on coastal flooding, with particular attention to major coastal cities in G20 countries and the Pacific Small Island Developing States. The projections underline that climate change threatens the lives and livelihoods especially of coastal communities. The brief was scientifically supported by Anders Levermann, researcher at the Potsdam Institute for Climate Impact Research.
The global sea level is rising at rates unprecedented in the last 3,000 years, according to the UN report that was issued by UN Secretary-General António Guterres. This rise is primarily due to melting land ice and the expansion of seawater as it warms. The publication outlines that in many areas of the western tropical Pacific, sea level has risen approximately 10–15 cm, close to or nearly twice the global rate measured since 1993. In the central tropical Pacific, the sea level has risen approximately 5–10 cm. This is extremely concerning since the average elevation many Pacific islands is only one or two meter above sea level, and a majority of the population lives in areas proximate to the coast.
The report predicts that with an estimated 3°C warming by 2050, many major cities in G20 countries will experience a sea-level rise of at least 15 cm. New Orleans (41 cm), Atlantic City (28 cm), and New York City (26 cm) are among those most affected. This rise poses risks not only to coastal communities but also to livelihoods, settlements, health, food and water security in broader regions.
Pacific Small Island Developing States are on the front lines of sea-level rise and will be impacted much more quickly and severely than other areas. Under the 3°C scenario, a median sea-level rise of 68 cm is projected, with many islands likely experiencing levels 10-30 cm higher than the global average.
Sea-level rise poses an immediate and significant threat to human life and socio-economic stability. Addressing this challenge requires urgent and deep cuts in global greenhouse gas emissions to meet the 1.5°C long-term target, along with a rapid scaling up of coastal adaptation and resilience efforts worldwide, the report states.
Future sea levels will depend on how much temperatures and greenhouse gas emissions stabilize. However, the researchers argue, even if emissions are halted, the heat already stored in the oceans will cause sea levels to continue rising for thousands of years.
Read the full technical brief here:
PDF source: https://www.un.org/sites/un2.un.org/files/slr_technical_brief_26_aug_2024.pdf
Source – PIK