Science:

Since at least 2008, scientists have warned that unchecked groundwater pumping for the city and for agriculture was rapidly draining [Iran’s] aquifers. The overuse did not just deplete underground reserves—it destroyed them, as the land compressed and sank irreversibly. One recent study found that Iran’s central plateau, where most of the country’s aquifers are located, is sinking by more than 35 centimeters each year. As a result, the aquifers lose about 1.7 billion cubic meters of water annually as the ground is permanently crushed, leaving no space for underground water storage to recover, says Darío Solano, a geoscientist at the National Autonomous University of Mexico, who was not involved with the study.

Some of the largest cities in the world, including São Paulo, Mexico City, Cape Town, Bangalore, and Tehran, are today facing critical water shortages. In the case of Tehran, the situation is so dire that Iranian president Masoud Pezeshkian has publicly said that the country now has no choice but to move its capital from Tehran to the southern part of the country:

Amid a deepening ecological crisis and acute water shortage, Tehran can no longer remain the capital of Iran, the country’s president has said.

The situation in Tehran is the result of “a perfect storm of climate change and corruption,” says Michael Rubin, a political analyst at the American Enterprise Institute.

“We no longer have a choice,” said Iranian president Masoud Pezeshkian during a speech on Thursday.

This will be expensive, and it won’t solve all of the country’s problems, but forcing a bunch of people out of the city will help to relieve some of the localized pressures. Tehran has a population of nearly 10 million, and the metro region is estimated at over 14 million, making it the second largest city in the Middle East.

Of course, there’s a city-building lesson in all of this: If you’re at this stage of capitulation, it means you’re too late. Water scarcity is about physical scarcity, but it’s generally also a failure of governance, infrastructure, and demand management. Proactive adaptation is always cheaper, easier, and safer than waiting until the last minute to adopt desperate measures.

Cover photo by Behnam Norouzi on Unsplash

Fred Wilson chose the perfect quote by William Gibson, here, to describe the current status of self-driving cars: "The future is already here — it's just not very evenly distributed." That's how it feels right now.

Waymo isn't in Toronto yet, but they are expanding rapidly throughout the US and elsewhere. Last week they announced fully autonomous driving in five new cities: Miami, Dallas, Houston, San Antonio, and Orlando. Autonomy is here, as we have talked about many times. There's no longer a question.

But what's interesting is that we're at the point in the hype cycle where expectations are not as inflated as they were a number of years ago (at least that's the way it appears to me). Years ago, everyone in real estate was talking about how it would disrupt parking requirements and reshape the landscape of our cities.

So when does this happen?

Fred ended his post by saying that "the downstream effects of this technology and behavior change are going to be profound." But he doesn't get into what these changes might be. Let's do a reminder of that now. Some of the most commonly believed consequences are as follows:

• Cars consume a vast amount of real estate and also spend the vast majority of their lives just sitting around idle. Switching to a "mobility-as-a-service" model will require dramatically less parking. This is going to force landlords to repurpose the parking they already have and it's going to encourage developers to build new buildings with reduced parking, or no parking at all. That will be good for housing affordability.

• However, the autonomous vehicles will need to park and corral somewhere at some point. My guess is that we will see something akin to rail yards today. This would be a good use for some of our excess parking, though this use won't require nearly as much. I would also imagine that many of the cars will leave the most valuable and dense parts of a city during off-peak periods.

• At the same time, it's not clear what the winning business model for AVs will be. Will it be a Waymo-like model where the ride-hailing company owns and operates all of the cars? Will it be a Tesla Robotaxi model where individuals own the cars and put them out to work? In this case, maybe the Robotaxis just go back to people's individual garages. Or will Uber remain the dominant platform? Meaning, an asset-light model that aggregates customer demand remains the highest-value component of the stack. Personally, I can't see Tesla's Robotaxi model being very lucrative for individual owners, so I'm inclined to look toward Waymo and Uber.

• Street parking will be replaced by a proliferation of pick-up/drop-off zones. This urban design problem will need to be solved as we dramatically increase the number of people getting in and out of AVs on busy urban streets.

• In the mid-1990s, Italian physicist Cesare Marchetti remarked that, all throughout history, humans have tended to cap their commute times at about 60 minutes per day. Something like a half hour each way. This became known as Marchetti's Constant. What this has meant is that as new technologies (streetcars, cars, and so on) allowed us to move faster within that 60 minutes, humans have tended to sprawl further outward. Will AVs do the same, and could they actually break Marchetti's Constant?

• As we all know, the key difference with AVs is that we will no longer need to pay attention to our commute. We could sit in an AV and sleep, work, watch a movie, or do whatever else we'd like. One can think of it like a mobile office or mobile living room. This should, in theory, make commuting long distances a lot more enjoyable and encourage even greater "super sprawl."

• The counterforce to this phenomenon is that if more people are willing to commute long distances in an AV, we will see demand greatly outstrip supply on our roads. In other words, traffic congestion in large cities will get even worse. I think this will force more/most cities to adopt congestion pricing. Politically, it will finally become acceptable, because now we'll be able to use "the machines" as our scapegoat. They're overrunning our cities! Ironically, this means that we won't adopt the thing that makes driving a lot better until we all stop driving.

So where do these opposing forces ultimately net out? Well, my view (and bias) is that human-scaled walkable communities will always have value. We are social animals. I also think that the experience within our cities will improve dramatically. Pedestrian safety will increase (the data already supports this) and far less space will be dedicated to cars. Good.

At the same time, I think that reducing commute friction will encourage an exurban explosion. Like the technologies that came before AVs, it's going to empower humans to further decentralize. What this will do is exacerbate the divide between our urban cores and our suburban and exurban fringes.

Of course, this is just me surmising. I don't really know. But AVs are here, and I think it's time we get back to discussing and planning for the second and third-order effects of this technology.