Kopp, R. E. et al. As a result, SRTM data generally overestimate elevation, particularly in densely forested and built-up areas. Researchers say it’s the first study to overlay affordable housing data — including both subsidized and free market low-income units — with sea level rise and flood risk data. Flooding can be costly because it can displace productive local economies dependent on density and convenient coastal locations. Wong, T. E., Bakker, A. M. R., & Keller, K. (2017). 2014, median climate sensitivity. Lett. In fact, based on CoastalDEM, roughly 110 million people currently live on land below high tide line. “Evolving Understanding of Antarctic Ice-Sheet Physics and Ambiguity in Probabilistic Sea-Level Projections,” Earth’s Future, 5, 1217–1233, https://doi.org/10.1002/ 2017EF000663 Downloadable data includes local, state and national analysis results, and our methods explain in detail how we generated our data and maps. Scientific Reports, 7(1), 3880. http://doi.org/10.1038/s41598-017-04134-5 Risk Zone Map shows near-term sea level rise and coastal flood threats. To the many organizations that have financially supported Climate Central and its sea level program, including The Kresge Foundation and The Schmidt Family Foundation. Jiangsu Province, China’s most densely populated province, could be highly vulnerable to chronic ocean flooding in just thirty years. In the decades ahead, sea level rise could disrupt economies and trigger humanitarian crises around the world. General Disclaimer & Legal Terms Future coastal flood threats in Kolkata, India A new interactive map from nonprofit organization Climate Central gives an unsettling visualization of what New York City would look like, should sea levels drastically rise. Net migration toward or away from low-lying areas will also contribute to population change. However, sufficiently accurate elevation data are either unavailable or inaccessible to the public, or prohibitively expensive in most of the world outside the United States, Australia, and parts of Europe. A flood peaking at a certain height will generally not inundate 100 percent of the nearby area below that height, if the flood peaks and redescends rapidly. Some projections indicate that flooding could cause tens of trillions of dollars in losses each year by the end of the century—or trillions per year, if extensive adaptation measures are implemented. World Meteorological Organization / Flickr, Interactive threat maps at coastal.climatecentral.org, Spreadsheet with country-level threats (CSV), http://doi.org/10.1038/s41598-017-04134-5, https://iopscience.iop.org/article/10.1088/1748-9326/7/1/014032/meta, https://doi.org/10.1007/s10584-016-1664-7, https://iopscience.iop.org/article/10.1088/1748-9326/aa6cb3/meta. 15. But the evidence suggests that those costs will be steep. Springer, Cham. CoastalDEM offers important improvements over the most common alternative. Climate Central built Surging Seas Risk Finder as a free web tool to help U.S. communities, planners and leaders better understand sea level rise and coastal flood risks. Wong, T. E., Bakker, A. M. & Keller, K. Impacts of Antarctic fast dynamics on sea- level projections and coastal flood defense. Remote Sensing of Environment 115, 1576–1587 (2011). Explore where, when and what could be impacted near you. All three strategies are being pursued to some extent in Atlantic City. Kopp, R. E. et al. Bright, E. A., Coleman, P. R., Rose, A. N. & Urban, M. L. Landscan 2010 (2011). 1. “Cities boom and bust,” said Benjamin Strauss, coauthor of the new study and vice president for sea level and climate impacts at Climate Central, which researches and reports on climate change. Back to top. Estimates of future economic losses from sea level rise vary depending on the amount of climate pollution and subsequent rise projected, as well as other factors, such as whether future population growth, innovation, or migration are considered. Shanghai, which is the country’s most populous city, is projected to be particularly vulnerable to ocean flooding in the absence of coastal defenses (box 4). SRTM is known to contain significant error caused by factors such as topology, vegetation, buildings, and random noise. Earth’s Future, 2, 383–406, doi:10.1002/2014EF000239 First, as the oceans warm due to an increasing global temperature, seawater expands—taking up more space in the ocean basin and causing a rise in water level. Nature Communications, October 2019, DOI: 10.1038/s41467-019-12808-z Claudia Tebaldi et al 2012 Environ. Special Thanks. Global warming has raised global sea level about 8" since 1880, and the rate of rise is accelerating. Sea level rise is a near term danger: today’s communities must make choices not just on the behalf of future generations, but also for themselves. Climate Central used machine learning techniques to estimate SRTM elevation error in coastal areas between (and including) 1 and 20 meters (3.3 and 65.6 feet) in nominal SRTM elevation. Box 4. Res. 2. This Climate Central map shows how […] Climate Central built this screening-level public web tool to help communities, planners, and leaders better understand sea level rise and coastal flood risks. More precise data gathered from satellite radar measurements reveal an accelerating rise of 7.5 cm (3.0 in) from 1993 to 2017,: 1554 which is a trend of roughly 30 cm (12 in) per century. The developing countries least able to protect their residents through coastal defenses or planned evacuations could be particularly vulnerable—and are responsible for just a small fraction of global emissions. To the many organizations that have financially supported Climate Central and its sea level program, including The Kresge Foundation and The Schmidt Family Foundation. Earth’s Future 2, 383–406 (2014). General Disclaimer & Legal Terms For more details, see Kulp and Strauss 2019, published in Nature Communications. This process was repeated for a number of different years and sea level rise model sensitivities, and under low, moderate, and high emissions pathways for heat-trapping pollution (Representative Concentration Pathways 2.6, 4.5, and 8.5), in order to achieve a comprehensive assessment of global coastal vulnerability. Globally, the average overestimate appears to be roughly six feet (two meters). Climate-change-driven sea level rise will continue to amplify coastal flooding in the coming decades. Global warming has raised global sea level about 8 inches since 1880, and the rate of rise is accelerating. Moderate emissions cuts (RCP 4.5), Kopp et al. In: Andreone G. (eds) The Future of the Law of the Sea. 7:11969 doi: 10.1038/ncomms11969 (2016). & Strauss, B. H. CoastalDEM: A global coastal digital elevation model improved from SRTM using a neural network. This study’s middle-of-the-road projections for 2030 range from one inch of local sea level rise in the northwest corner of Washington State, where the land is slowly rising, to 8 inches near New Orleans, where it is sinking. Underestimates of flood heights produce underestimates of inundation. 11. The Social Vulnerability Index , which shows areas of high human vulnerability to hazards, is based on population attributes from Census 2010 (e.g., age and poverty) and the built environment. Every global shore touches the same ocean, and the ocean is rising. In recent decades, China’s coastal provinces have attracted millions of migrants from the country’s interior and have become important centers in the global economy. It is the peer-reviewed scientific paper upon which this report is based. (See spreadsheet download in “related resources.”). Shortridge, A. And in states around the world, mass displacement could shape national politics. Sea level projections to AD2500 with a new generation of climate change scenarios. The Climate Central sea level rise group conceived and maintains this tool. Climate Central then added up populations (Landscan 2010) within the identified areas to compute how many people today live on implicated land. Interactive global map showing areas threatened by sea level rise and coastal flooding. This approach is highly efficient but overestimates inundation, because coastal floods take time to travel over land. Use the “+” button to zoom in. The Climate Central sea level rise group conceived and maintains this tool. The potential response of major ice sheets to rapid warming remains an area of deep and consequential uncertainty. By 2100, CoastalDEM’s elevation data show, land currently home to 200 million people could fall permanently below the high tide line. Population exposure estimates do not factor in potential coastal defenses, such as seawalls or levees. Read More, Members of the Climate Central staff and board are among the most respected leaders in climate science. Key Points. Such cuts would reduce the total number of people threatened by annual flooding and permanent inundation at the end of the century by 20 million, relative to moderate emissions cuts made roughly in line with the Paris agreement. Proceedings of the National Academy of Sciences, May 2019, 201817205; DOI:10.1073/pnas.1817205116 However, it’s uncertain whether that acceleration will continue, driving faster and faster sea level rise, or whether inter… New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding. By 2050, land now home to 93 million people could be lower than the height of the local average annual coastal flood. In low-elevation coastal areas in the United States with population densities over 50,000 people per square mile, such as parts of Boston, Miami, and New York City, SRTM overestimates elevation by 15.5 feet on average. Where lidar data are not available, researchers and analysts rely on one of several global datasets, most typically data sensed from Earth’s orbit through a NASA project known as the Shuttle Radar Topography Mission, or SRTM. Climate Central surveys and conducts scientific research on climate change and informs the public of key findings. Climate Central Flood Risk Map Type your address in the search bar. Lett. Our scientists publish and our journalists report on climate science, energy, sea level rise… Tighe, M. & Chamberlain, D. Accuracy Comparison of the SRTM, ASTER, NED, NEXTMAP USA Digital Terrain Model over Several USA Study Sites DEMs. Back to top & Messina, J. Spatial structure and landscape associations of SRTM error. This clouds understanding of where and when sea level rise could affect coastal communities in the most vulnerable parts of the world. Environmental Research Letters 12, 044013 (2017). Res. Source: World Meteorological Organization / Flickr, New elevation data show that by midcentury frequent coastal flooding will rise higher than areas currently home to hundreds of millions of people, As a result of heat-trapping pollution from human activities, rising sea levels could within three decades push chronic floods higher than land currently home to 300 million people, By 2100, areas now home to 200 million people could fall permanently below the high tide line, The new figures are the result of an improved global elevation dataset produced by Climate Central using machine learning, and revealing that coastal elevations are significantly lower than previously understood across wide areas, The threat is concentrated in coastal Asia and could have profound economic and political consequences within the lifetimes of people alive today, Findings are documented in a new peer-reviewed paper in the journal Nature Communications. Sea level rise is a game of millimeters a year, but those millimeters add up to a huge amount of water entering the world’s oceans. Explore where, when and what could be impacted near you. Finally, the relatively coarse spatial resolution of LandScan data likely introduces some error into results (LandScan estimates population on a global grid of roughly 1km x 1km cells). To the many organizations that have financially supported Climate Central and its sea level program, including The Kresge Foundation and The Schmidt Family Foundation. In recent years, scientists have suggested that the sensitivity of Greenland and especially Antarctic ice sheets to global warming could make the global ocean rise more quickly than previously believed. The Intergovernmental Panel on Climate Change (IPCC) stated last month in a special report on the oceans that global average sea levels could rise by up to … Bright, E. A., Coleman, P. R., Rose, A. N. & Urban, M. L. Landscan 2010 (2011). 2014) to find regions that could permanently fall under the new high tide line in the coming decades. As humanity pollutes the … “Ice sheet contributions to future sea-level rise from structured expert judgment.” Proceedings of the National Academy of Sciences, May 2019, 201817205; DOI:10.1073/pnas.1817205116 The second mechanism is the melting of ice over land, which then adds water to the ocean. But the danger of permanent inundation is by no means be limited to Asia. Back to top. In Bangladesh, where per-capita emissions and per-capita GDP are more than thirty times lower than in the United States, flooding-driven displacement is not just a future prospect; it has already arrived. West Bengal and coastal Odisha are projected to be particularly vulnerable, as is the eastern city of Kolkata (box 5; Home to 26 million people, Shanghai is China’s biggest single urban agglomeration. Together, those six nations account for roughly 75 percent of the 300 million people on land facing the same vulnerability at midcentury. United Nations, Department of Economic and Social Affairs, Population Division (2018). The residents of small island states could face particularly devastating losses. Sea level rise is one of the best known of climate change’s many dangers. An independent organization of leading scientists and journalists researching and reporting the facts about our changing climate and its impact on the public. SRTM data measure the tops of features that protrude from the ground—such as buildings and trees—as well as the ground itself. Predicted Sea Level Rise Impacts on Major Cities from Global Warming Up to 4°C. Nauels, A., Rogelj, J., Schleussner, C.-F., Meinshausen, M. & Mengel, M. Linking sea level rise and socioeconomic indicators under the Shared Socioeconomic Pathways. Muis, S. et al. Sea level rise could have wide-ranging political consequences. In fact, using CoastalDEM’s improved data on coastal elevation makes a bigger difference in projected exposure to ocean flooding than does switching from a low-end to a high-end sea-level-rise scenario when SRTM data are used.