Well, if you're going to be wholly ignorant about it....

At least 21 - yes, count ‘em, 21! (over 20 is at least 21, no?) - politicians have signed up to be rulers of the world. Sorry, that’s not quite right, have demanded the power to create a Global Green New Deal in which all our lives are lived according to their precepts.

One of whom tells us this concerning what must be done:

Manon Aubry, a French MEP, said governments must focus on social justice and the climate. “As the consequences of the climate crisis become more and more alarming, inequalities are growing and the poorest are hit hardest by the impacts of a changing climate. If we want fair, systematic and effective climate policies, we need a radical shift away from free trade and free-market ideology.”

It’s OK, we do grasp that some people just don’t like trade. Who are these filthy foreigners who do things better than our own folks at home? And why should they be allowed to? Poujadism has not been entirely unknown in France in the past after all.

We are also aware of Polanyi and his insistence that it is the local web of personal interaction which gives meaning to economic life. We disagree but accept that some don’t.

Opposition to free trade can thus run on that spectrum from rampant xenophobia to a principled moral stance, however wrong either or both might be.

However, the one thing that isn’t going to work is killing trade to beat climate change. This was tested in the economic models which underpin all discussions of climate change, the SRES (and still do underpin, the RCP and so on models are all derived from the same place). Whatever our views on free markets red in tooth and claw - as opposed to a more comfy social democracy - it’s an explicit insistence in those models that a more globalised, free trading, world produces a better outcome than a more regionalised and fragmented one.

In the jargon, A1 is better than A2, B1 better than B2. A standing, roughly, for free market capitalism, B for something more kumbaya. But 1 for that globalised and trading world, 2 for one less so than we currently have.

The better being defined by fewer and richer people, which is nice enough. But more importantly for the argument here, with less climate change because lower emissions.

The why should be easy enough to understand. Trade just means that things are done where it is most efficient to do them. Therefore, for any level of living standard to be enjoyed by a population of whatever size, trade will lead to the use of fewer resources to achieve that economic wealth. Or, the same statement moved around a bit, for any given level of resource use the living standard to be enjoyed will be higher.

Trade means, holding other things equal, less climate change. Therefore the one thing we don’t want to do as part of our actions against climate change is to restrict trade.

As Ms. Aubry is entirely ignorant of this obvious point then we’ve not got to pay much more attention to her demands to rule the world, do we? Well, other than to just reject the idea as being ludicrous. But then Caroline Lucas is involved so that last point should be obvious anyway.