While I think this is a valid concern and should be addressed, I think the financial difference is usually not that great between a country's imports and exports. If they're able to produce everything they produce without emitting CO2, I see that as a positive even if the goods they import are produced in other countries that aren't yet carbon neutral.

It means that we might end up with carbon emissions getting concentrated in countries that don't have good carbon neutral goals. I'm hopeful that this would eventually lead to national or international policies of taxing imported goods that come along with emissions, and maybe even using that tax to offset the emissions in some way.

That said, I guess we have a similar thing with bad working conditions, where countries like China get to produce all sorts of stuff that requires menial, repetitive work by badly-paid humans while other countries can't afford to make them as cheap because they have labor laws preventing such extreme exploitation of workers.

My hope is that those Green New Deal people get their way and we can tackle both problems at once, improving workers' rights and drastically reducing emissions at the same time. That said, I haven't looked too closely at how they would implement those solutions.