Sample Headlines and Excerpts

Rising Seas Will Erase More Cities by 2050, New Research Shows by Denise Lu and Christopher Flavelle/ New York Times October 29, 2019

“Rising seas could affect three times more people by 2050 than previously ... research, threatening to all but erase some of the world's great coastal cities…”

Global Warming Will Drown Bangkok, Shanghai, Mumbai by Tessa Stuart/ Rolling Stone  October 29, 2019 

“150 million people are currently living in places that will be below high-tide in 30 years, according to new research…[which] paints a grim picture: whole swaths of Vietnam, Thailand, coastal China, India, Egypt and Iraq swallowed by ocean.”

Rising Seas Are Going to Drown Way More Cities than We’d Thought: Study by Eric Levitz/ New York Magazine Intelligencer October 29,2019

“ Mumbai — the financial capital of what will soon be the world’s most populous country — is now at risk of being entirely erased by mid-century. If the Princeton researchers’ projections are correct, averting mass death and suffering in the coming decades will require not only rapidly reducing carbon emissions and ramping up construction of seawalls and other fortifications but also facilitating mass migrations away from low-lying cities and islands and toward higher ground.”

What Does the Actual Study Say?

The study authors applied a new model to calculate the global land area below high tide lines this century. Based on this model, they estimated 110 million people already occupy land lower than current high tide lines and that somewhere between 150 - 630 million people currently occupy land that would be lower than the high tide lines in 2100, depending on the emissions scenario. Their study does not address the plausibility of different emissions scenarios, future population levels in high-risk areas, migration patterns, or sea defenses to minimize flood risk. In other words, the authors are not saying cities are going to “drown” or be “erased”.

What Wasn’t Mentioned in the News Stories:

Living below the high tide level doesn’t mean catastrophe - as mentioned, 110 million people already do. How do they manage this feat? By such commonsense measures as building levees, seawalls, and drainage systems, creating wetlands designed to flood, and maintaining mangrove forests that buffer storm surges - as many coastal cities are already doing or planning to do. Although flood defense projects often involve large initial expense, some governments have concluded “the economic performance of most measures seems highly positive, suggesting that adaptation will generate high returns on investment” (Scussolini et al, 2017). And factoring in those returns makes all the difference in the world when considering the cost of climate change adaptation. Per The Economist: 

“Predictions of the costs of climate change are often far higher when analysts rule out the possibility of adaptive behaviour. A study published last year considering the global costs of coastal flooding, for example, estimated that floods will reduce real global GDP in 2200 by 4.5%—unless the effects of adaptive investments and migration are considered, in which case the loss works out as just 0.11%. A new report by the Global Commission on Adaptation, a group convened by 20 advanced and emerging economies, identifies $1.8trn in potential adaptation investments which, if realised between 2020 and 2030, would yield estimated net benefits of $7.1trn.”

Parting words: Optimism without an action plan invites complacency. Optimism with an action plan invites moving forward with the plan.

References:

Climate change is forcing Asian cities to rethink their flood defences The Economist September 19, 2019

Kulp, S. A. and B. H. Strauss (2019). "New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding." Nature Communications 10(1): 4844. https://doi.org/10.1038/s41467-019-12808-z

Humanity will find ways to adapt to climate change The Economist September 14, 2019

Mia Lu and Joanna Lewis  (2015) China and US Case Studies: Preparing for Climate Change - Shanghai: Targeting Flood Management Georgetown Climate Center

Scussolini, P., Tran, T. V. T., Koks, E., Diaz‐Loaiza, A., Ho, P. L., & Lasage, R. ( 2017). Adaptation to sea level rise: A multidisciplinary analysis for Ho Chi Minh City, Vietnam. Water Resources Research, 53, 10,841– 10,857. https://doi.org/10.1002/2017WR021344