Sea-Level Rise
More greenhouse gases (GHG) in the atmosphere means higher temperatures on Earth. As a result, frozen surfaces melt and bodies of water expand — the main drivers of sea-level rise. In the 20th century alone, it is estimated that seas and oceans have risen by an average of 11-16 cm. How can this phenomenon affect our coastal populations, now and in the coming years?
To answer this question, researchers Scott Kulp and Benjamin Strauss created an algorithm (aka CoastalDEM) which measures land exposure to extreme water levels. Combined with population distribution data, they could estimate the number of humans at flood risk due to sea-level rise, today and by the year 2100 under different GHG emissions scenarios.
Based on their study, I designed the visuals below so we can compare the number of people at coastal flood risk per country today (plain color), in 2100 under a moderate GHG emissions scenario (dots), and in 2100 and a scenario with high emissions resulting in the melting of antarctic ice (white). Note that these numbers are given on a logarithmic scale.
Africa. With over 95% of inhabitants living along the Nile river and areas as low as 133 m below sea level, Egypt is the African country with the highest number of people at risk of coastal flooding, today and tomorrow.
Asia. By far the most heavily impacted region. According to projections, 70% of the people that will be affected by flooding in 2100 are located in eight Asian countries: China, Bangladesh, India, Vietnam, Indonesia, Thailand, the Philippines, and Japan.
Europe. The Netherlands are already largely impacted by rising sea levels. As of 2019, about half (8.5 million) of its population lives in areas below sea level.
North America. Given the size of their populations, the U.S., Canada, and Mexico are expected to see the highest numbers of impacted people. But as a percentage of population, Caribbean countries are more greatly at risk. For instance, the Bahamas island is especially vulnerable to sea level rise and flooding due to its relatively flat land.
Oceania. By 2100, Polynesian countries are projected to see large increases in the number of people at risk of flooding, even with moderate GHG emissions. Tonga islands sit in warm waters that have been rising by 6 mm each year, which is nearly double the average global rate.
South America. As the largest South American population and with massive coastal cities, Brazil is the country most at risk of flooding. Notably, thanks to a lot of mountainous terrain and municipalities situated at high elevation, no country in South America faces a flood risk impacting more than 1 million people.
Workflow
To design these infographics I first gathered thoughts on paper, then explored data in Excel and used tidyverse functions in R to generate vector elements. I customized the graphics in Illustrator and styled them in Photoshop using layer blending, effects, and masking.
