This is just insane. Not only are cars themself mostly unnecessary, if the right infrastructure is provided, but SUVs also use more resources to run and be produced then small cars, without any advantage over them. So an obvious waste, which could easily be cut to reduce emissions.
Source IEA: https://www.iea.org/commentaries/suvs-are-setting-new-sales-records-each-year-and-so-are-their-emissions
The biggest problem with your traditional square-rigged ships is that the masts get in the way of modern cargo-handling methods.
Also, according to Wikipedia, the largest sailing ship ever made (SS Great Eastern) had a gross register tonnage of 18,915, while the largest container ship (MSC Irina) has a gross tonnage^1^ of 233,328. In other words, the sails would have to be an order of magnitude larger than any that have ever been made before.
There are some newer sail technologies, such as rotor sails and kite sails, but those are apparently designed to shave 5-10% off the fuel consumption of a primarily engine-powered ship, not act as the primary means of propulsion.
And the other big problem with any of those technologies is that even if they could propel the ship by themselves, they still can't fully replace engines because logistics companies won't tolerate getting becalmed anymore. And even if that weren't an issue, you've still got to have an engine for maneuvering in tight channels and ports anyway.
In order to completely eliminate having to burn fuel, nuclear really is the only option.
(^1^ GRT and GT aren't quite the same thing, but there's no simple conversion between the two. That said, they should "not differ too greatly" according to Wikipedia.)
Oh, I fully agree there are multiple logistics and engineering challenges that would need to be overcome. But im also aware we are orders of magnitude more advanced than when Great Eastern was designed and built - we used to think we would never get to the moon because a spacecraft couldn't carry enough coal.
If you could eliminate 80% of fuel costs you could make smaller vessels much more cost effective which, let's be honest, is the biggest hurdle. Make it sail 95% of the time, small maneuvering engine and electric tugs can eliminate alot of the variable costs... and they only cruise at 10-12kt anyway.
Ships don't work that way. There are a couple of reasons other than fuel economy why they keep building them as big as they can:
Hull speed is proportional to waterline length. In other words, bigger ships can go faster.
Bigger ships have better economies of scale for the crew.
Also, winds aren't reliable enough for any ship to sail 95% of the time, unless you count being becalmed as "sailing."
Yes, theoretical hull speed is proportional to hull speed, but mondern cargo ships aren't optimized for speed - old school clippers were.
They are also more cost effective for crew - which is why you need to automate as much as possible. Electronic winches, hydraulic booms or sheets, instance access to weather, Electronic monitoring, tides and conditions forecasting and access for a harbour pilot to take over could eliminate alot, if not all of transit crew.
Will it be as fast and reliable- no. But if you can make the cost savings outweigh the drawbacks you can make a presentable business case.