And it's not the UK. In order to meet the Paris accord and the 2030 target, the EU needed the big reduction by the UK. When, not if, the UK Brexits, the UK contribution will have to be met by other countries.
The UK, on the other hand, has already met the 2020 requirements and is working on 2030 hard. But I expect that to be slightly derailed until the full impact of Brexit is known.
So the EU is already starting to wake up to the "contribution" the UK made to the EU. All those countries who told Cameron "you may NOT" are going to rue the day. This is just the first in a long list of items where the UK was a significant contributor to the EU and was never given recognition for it.
WM and I have often said that the UK should have engaged more and shaped the EU more. However I was reading an interesting article, yesterday, which was discussing how France and Germany clubbed together on many occasions to explicitly deny the UK influence and power in the EU.
There are a lot of things about Brexit I'm really going to enjoy. One of them is the whinging EU's sudden realisation that they were the "bad guys" and now they're going to have to face the cost. The cost of additional CO2 mitigation is one thing, the cost of re-funding the UK net contribution to the budget is going to be something else again. I expect the EU to dangle a lot of large carrots out there to try and keep that money. I truly hope that the UK negotiators don't bite. They'll be poisoned...