Former director of NASA's Goddard Institute for Space Studies (GISS), James Hansen, warns that Rising Sea Levels are the most dangerous component of the climate change jigsaw because higher sea levels will bring about population displacement, mass migrations inland or across seas, global collapse of economies, and social upheaval such that "the planet could become practically ungovernable," as reported by Dom Galeon in Futurism.

Rising sea levels pose a threat greater than rising temperatures

More dangerous than rising temperatures, rising seas threaten the survival of coastal cities, and upward of half of the world's major cities are coastal.

Migrations forced by an increase in sea levels will put pressure on governments and resources. When the pressure comes from multiple major coastal cities, as well as small island villages, Ungovernable Chaos will ensue as strained resources collapse and economies fail.

As early as 2014, Fuiji official Alipate Bolalevu identified 600 villages threatened by climate change and encroaching seas, for which relocation to higher ground — like the earlier relocation of the village of Vunidogoloa — was a pressing concern, as reported in 2014 by Brianna Piazza in Australia's Special Broadcasting Service (SBS).

According to Hansen: "The economic implications of that, and the migrations and the social effects of migrations ...

the planet could become practically ungovernable...."

Elevated seas in Europe and America

Rising seas are an international issue, negatively impacting European, Asian, and American cities, as well as island villages and coastal towns.

Senior climate analyst for the Union of Concerned Scientists (UCS), Erika Spanger-Seigfried, said, in relation to a newly published study of U.S.

chronic coastal flooding called "When Rising Seas Hit Home," that 90 U.S. cities, mostly in Louisiana and Maryland, are already today chronically inundated by higher sea levels caused by climate change. Having mapped the entire country, UCS warns of how quickly that number will grow, reaching 170 cities within 20 years, according to conservative estimates.

In Europe, Amsterdam is preparing to take action by developing their "Space at Sea" project. The project designs floating cities for a sustainable life in sea waters, as reported by Elana Glowatz of International Business Times (IBT).

Avoiding 'ungovernable chaos'

Hansen acknowledges the need to turn attention to modeling predictions of what could come and to the negative potential of climate change, but he emphasizes that the greatest value of climate change predictions and potentialities is as indicators of actions needed to prevent ungovernable chaos in a world overwhelmed by rising seas. Hansen warns that the pressing focal point for climate change is not warming temperatures, dangerous though they be, but it is rising sea levels, which carry more global danger than warming temperatures.

Former GISS Director James Hansen, bio sketch

James Hansen is a former director for NASA of the Goddard Institute for Space Studies located at Columbia University in New York City. Associated with the Columbia Earth Institute and School of Engineering and Applied Science, GISS is a laboratory in the Earth Sciences Division of NASA's Goddard Space Flight Center, as explained on the GISS home page of the NASA website.

Hansen is currently Adjunct Professor of the Earth Institute of Columbia University, as explained in the biographical material presented by

Hansen is currently involved with a lawsuit against the U.S. government "alleging complicity on climate change, which Hansen and his fellow litigants argue is a violation of the equal protection clause" of the Constitution, as Hansen discussed in an interview with David Wallace-Wells for New York Magazine.