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Sea Level Rise Research

By David D. Newell Projects

Defending a single seaport against two meters of sea level rise is an engineering problem we already know how to solve; defending every major port on roughly the same schedule is a manufacturing problem, and manufacturing has a ceiling. When we started, nobody had a defensible estimate of how much cement the world can actually produce in a given year, so closing that gap became the contribution of our research.

What was SUPERSLR?

I walked into the wrong room freshman year at Stanford and got involved with SUPERSLR, Stanford University’s Project on Engineering Responses to Sea Level Rise. It remains the best argument I know for showing up to the wrong meeting. The project asked two questions:

  1. Could seaports around the world protect themselves against 2 meters of sea level rise?
  2. Does enough construction capacity exist to meet the additional demand from such a massive project?

The first question belongs to civil engineering, where seawalls, levees, and surge barriers are well-understood structures; the second belongs to industrial supply chains, and it turned out to be the harder of the two.

Why the second question is the hard one

Climate adaptation carries an awkward property that ordinary construction does not: global changes arrive everywhere at once, so many similar projects come due in many places within the same window. Any single port can source concrete without difficulty; several hundred ports building storm surge defenses simultaneously are competing for the same finite industrial output.

That competition turns a fairly unglamorous number, global cement production capacity, into the variable that decides whether a worldwide adaptation program is feasible at all.

How much cement can the world actually make?

Here the existing literature fell short: as we wrote in Is adaptation sustainable?, production rates for construction materials are widely published, but potential capacity at a global scale is poorly understood. Methods that work well within a single region prove ineffective globally, because regional data is uneven and plants rarely run at their nameplate maximum.

We therefore built a four-step hybrid method to estimate maximum global cement capacity:

  1. Collect the available capacity and production data.
  2. Select the top regional capacity holders.
  3. Compute utilization rates for those regions.
  4. Back-calculate global capacity from observed production.

The contribution is the method rather than any single headline number. It gives economists, climate scientists, and policymakers a defensible way to test whether a proposed adaptation program sits within the world’s industrial reach, instead of assuming that materials will simply appear on demand.

How much material would the ports need?

My SUPERSLR collaborators quantified the demand side. In A method to estimate climate-critical construction materials applied to seaport protection (Becker, Chase, Fischer, Schwegler, and Mosher, Global Environmental Change 40, 2016, pages 125 to 136, a paper on which I am not an author), the team applied a minimum-assumption credible design to 221 seaports. They estimated roughly 436 million cubic meters of construction material to protect those ports against 2 meters of sea level rise, and those 221 ports represent fewer than 10 percent of the world’s total.

Taken together, the two halves frame the problem: demand is enormous but calculable, running to hundreds of millions of cubic meters for under a tenth of the world’s ports, while supply, meaning how much cement the world can produce in a given decade, is the constraint nobody had properly measured.

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