No, not really
A useful and possibly even important start to understanding the world is to get things the right way around. To be clear about what is happening out there in reality so as to be able to consider how to deal with it.
A new European Union carbon border tax could lead to tariffs being slapped on British imports of steel, cement and aluminium in a climate change trade war after Brexit.
No, not really. In fact, not at all.
British imports are the things imported into Britain. What tariffs, carbon or otherwise, are going to be on them is something that will be decided by the British government, not the European Union.
What is actually meant is the opposite, that British exports of such into the European Union will have such a carbon border tax added to them. But even that’s not correct.
Tariffs are paid by the consumers of the items - the importers - not the producers or exporters. Thus the actual claim here is that the citizens of the European Union are going to be taxed by the European Union for their temerity in buying British steel. An event which is considerably less scary - they’re getting taxed by their rulers, not us by our or even us by their.
We can even strip this back. Forget why they don’t want to buy British steel and think on that basic fact that they don’t. We’d better stop making steel in Britain for foreigners then, hadn’t we? There’s no point in going to all that effort to make something that no one wants, is there? We should devote those resources to making something else. Either that foreigners do want to purchase from us, or, something that will raise our own living standards, something that we ourselves want.
The correct answer to someone saying they don’t want our exports is shrug, we’ll do something else then.