Of course that doesn’t include domestic trade, by far the majority of trade, and that must have a somewhat lower C02 profile. But it’d be interesting to know how much lower transporting tomatoes by road 100 miles compares with shipping them 800 miles.

A recent study suggests that international shipping is currently responsible for 4.5% of global CO2 emissions, almost twice that of the aviation industry.

Back of the fag-packet calculation suggests that if marine emissions are roughly 1.2 billion tonnes of CO2 per annum, then the industry is burning more than 410 billion litres of fuel oil each year.

It’s entirely unsustainable from a resource standpoint, and is a significant factor in anthropogenic climate change.

“We should reduce international trade because it will destroy the world for future generations” is defensible – it depends on how much, factually, the current trade regime is destroying the world for future generations, and that’s the part where we disagree.

“We should reduce international trade because cheap imports are destroying jobs at home” is not defensible, because cheap imports are a benefit to us whereas jobs at home aren’t…

Speaking as a protectionist, I suspect it’ll be the free-trade globalisers who’ll be lined-up against a wall, come the revolution.

If sustainability is a priority (and I’d argue it’s the over-riding priority), then schemes to encourage a greater localisation of production are absolutely necessary. And such schemes would cetainly appear protectionist to free-trade evangelists whose central delusion is either that goods get transported from China to here in a sustainable manner, or that sustainability is irrelevant.

After all, the people most affected by our unsustainable lifestyle are future generations as yet unborn. And they’re not objecting, right?