What to do before our cities submerge
by Mike Meyer
Will we survive the next fifty years? Will our children and grandchildren make it to the next century? For the answers to those questions to be positive will require planetary level cooperation unique in our history. These are not academic or even abstract questions but gut punchingly real right now.
Having to deal with incompetent political leaders who are not completely knowledgeable on global warming, rapid social change, and planetary collaboration is a distraction we cannot afford. Such people need to be removed from positions of authority and prevented from creating disasters that will mean the deaths of hundreds of millions by the end of this century. Arguable those deaths have already begun in steadily increasing refugee migrations. Here is what we are facing.
We will reach eight billion people as soon a 2024 and nine billion as soon as 2035. Already 55% of our population is urban and that will reach 70–80% by 2050. Homo Sapiens have evolved as urban dwellers over the last ten thousand year and, if we survive, will be almost exclusively urban by the end of this century.
Unfortunately we are struggling and, so far, failing, to delay global warming. Without concentrated action this will increase sea levels significantly through the end of this century. Of our preferred urban habitats 65% of those cities with populations above 2.5 million are coastal. 60% of our current population lives in coastal areas. We prefer to live in coastal cities. Current projections, which have been steadily increasing, now put the sea level rise at 3–4 feet by 2100 and as much as 49 feet by 2500.
While people can choose to ignore the far off date of 2500 they cannot ignore the next eighty years. My youngest grandchildren will be in late middle age by then or maybe effectively younger as life expectancies increases and eighty becomes the current fifty. For those, almost everyone, who are younger than I am will have children as well as grand children living then. These are not distant descendants but our kids and grandkids. Look at them and then real on.
By the end of this century we will have lost much of our coastal urban areas. In the US New Orleans may be an island protected by dykes and south Florida will be gone. The northeast urban region will protected by giant levies and/or made up of new floating neighborhoods. Low lying countries such as Bangladesh will be gone and Pacific islands will be gone or much smaller.
Much of South and Central America and the center of Africa will be uninhabitable due to heat. Those populations will have migrated north and south and added to our vast urban populations.
What will we do? Obviously coastal cities will not disappear. Some may need to be abandoned but others will build dykes while shifting the most threatened populations inland. Mid continental cities will grow steadily. China has been building huge, almost uninhabited cities in central areas that will become new urban centers as sea levels rise. At least they have been acting on the realities that we face. What have the rest of us done?
People have been working on plans to create floating cities and cities on the sea floor. Floating cities in coastal areas are probably the easiest to achieve and may well be a first response for our largest coastal urban areas as sea levels rise. While these are viable alternatives and interior cities such as Chicago, St. Louis, Louisville, Denver, and Spokane will grow tremendously, remember that increasing heat will reduce the population of the southern and central part of the US. These cities may become enclosed to provide climate control.
But there is another and better option and that is to move off this planet and into orbit. It seems to me that it may be less of a challenge to build massive, artificial gravity orbital habitats than to construct anything other than fairly shallow, ocean floor cities. One of the great advantages of orbital habitats is access to asteroids and other planets. This also has the benefit of easy transport to the earth’s surface as an orbital habitat does not have a gravity well that needs to be countered on outbound shipments.
We also have a solid track record in the International Space Station that is a small international orbital habitat. It does not, however, have artificial gravity so we need a different design. The tremendous focus on reusable boosters and, now, the provisioning of ISS transport via commercial rocket services makes this an easy way to expand. We know the story and we have the tools. These simply need to grow and our vision needs to seriously expand.
Space habitats were already being designed in the early 20th century with the classic wheel originally suggested as a way to generate artificial gravity by Herman PotoÄnik. He even suggested placing them in geosynchronous orbit very early in the 20th century.
Wernher von Braun and Willy Ley updated this idea in 1952. The three decker station was designed to support a mission to Mars. It would support 80 people and spin at 3 RPM producing about one third earth gravity.
In 1975 NASA ran a summer institute at Sanford University with a resulting new, city sized version of a Von Braun Wheel .
The Stanford Torus was designed to support between 10,000 and 140,000 people on the inside of the torus or donut. The central hub in all versions of this provides zero gravity docking and utility space with spokes out to the torus where people live. The smaller version of the Stanford Torus would be 1.8 km in diameter revolving at about 1 RPM producing between .9 and 1 Earth gravity on the inside living area.
While common to science fiction the torus is complex to build and pressurize in orbit. Things have come a long way and there is a design to add a centrifugal sleeping area to the ISS. This is in debate as the ISS is a research facility for zero gravity so the preference is to not waste money on artificial gravity.
The most likely version for large habitats would be an O’Neil Cylinder named after it’s inventor Gerard K. O’Neil in his 1978 book, The High Frontier: Human Colonies in Space. These, as designed by O’Neil, would be twenty mile long and five mile wide cylinders built in counter rotating pairs to counteract gyroscopic effects.
The cylinders would rotate about twenty-eight times per hour to maintain normal earth gravity. These would have a center rod connected to plates on each end via a baring arrangement. The center rod would include mirrors redirecting sunlight to the inside of the cylinders and would also be zero gravity at that center.
Options for building O’Neil Cylinders include hollowing out asteroids. This suggests a very large project but would not involve moving huge amounts of construction material into Earth orbit. O’Neil’s plan was based on using lunar material to build the cylinders utilizing a mass driver to boost the materials from the lunar surface.
The last version of the O’Neil Cylinder was 8 km in diameter and 32 km long. This would be able to house a very large population. We are now talking major urban space with sections of the ‘land’ designed for agriculture and recreation.
One of the very large benefits of this approach of relocating our drowning cities is that, while built in Earth orbit, these habitats could be moved to other orbits with adequate energy made available. Space habitats would be clustered in geosynchronous orbit providing closer connection to an Earth city or region.
It is also, ultimately, possible to move these habitats to the outer solar system or the asteroid belt for mining and production based on materials there.
This is a very real opportunity and we are facing the need to move beyond this planet’s surface as quickly as possible. We are being forced to act and we will need to act in collaboration to overcome our initial failures in planetary maintenance.
My main point is that we can do this as the knowledge and technical abilities are available. We need to overcome our ignorance and inability to collaborate and manage ourselves at a planetary scale. It’s time to get started on this now.
We did the moon in ten years sixty years ago. Let’s do Orbital City One by 2030.