Climate change is exacerbating potential flooding crises at high- and low elevations, three new studies warn. Approximately 15 million people worldwide — more than half in India, Pakistan, Peru, and China — live in the shadow of glacial lakes prone to sudden and catastrophic outbursts, according to a study published Tuesday in Nature Communications.

A second study, awaiting publication in a peer-reviewed journal, cataloged more than 150 of such floods and climate change, mainly caused by the extraction and combustion of fossil fuels, accelerating glacier melt, making the lakes bigger and more dangerous. “We had glacier lake outburst floods in the past that have killed many many thousands of people in a single catastrophic flooding event,” co-author of the Nature Communications study Tom Robinson told the AP. “And with climate change glaciers are melting so these lakes are getting bigger, potentially getting more unstable.”

New mapping reveals increased coastal threats

A separate study in Earth’s Future, a publication of the American Geophysical Union, warns sea level rise will submerge more than twice as much land as previous models had projected. Because coastal elevation mapping is so expensive, the findings — obtained using laser detection from a satellite — are especially stark in developing countries where more coastal vulnerability mapping has not taken place.

“Think of Lagos in Nigeria,” co-author Aljosja Hooijer told Inside Climate News. “They’re poorly managed and they don’t have geographic data. They don’t have elevation models and they don’t do spatial planning, and they use groundwater. They are literally pumping themselves downward, because the ground subsides where you extract groundwater. And these are all soft, sloppy coastal soils, lots of mangrove clay, stuff that can subside by many meters easily. So that’s like a triple whammy.” (Glacial lakes: (AP, Washington Post $, E&E $, CNN, Reuters, AFP, South China Morning Post, BBC; Coastal vulnerability: Inside Climate News; Climate Signals background: Glacier and ice sheet melt, Sea-level rise)