Saudi aluminium smelter: in my opinion NG should be conserved for premium uses such as Haber-Bosch nitrogen compounds. In other words we should recycle more aluminium, use less (soda in paper cups?) or smelt using hydro. To that end I would slap a hefty carbon tax in lieu on Saudi aluminium as it arrives in port.

That sounds more like a NG-wasting tariff.

I'd slap a carbon tariff on any place that's spewing carbon dioxide. Tchotchkes from China? They burn coal like crazy there -- carbon tariff. Sugar from Brazil? Tax 'em for chopping down the rain forest ... etc.

But then I want to see some relocalization anyway :)