Anything forward from this current point in time is the unknown
Apart from one thing anyways
There is absolutly nothing that the UK can possibly do to slow, prevent, or reverse climate change, irrespective of whether it is entirely natural or as a result of human activity.
Absolutely nothing
And this is why...
A quarter of those emissions are being generated by not much more than 10% of the worlds growing population.
China and India are large emitters because they have large populations. Not because the people live particularly well. And most of Africa, a continent with a population that will exceed that of the entire planet at the end of WW2 by 2050 or so. isn't even on the list. (lumped together for now with south America and so on in "Rest of World")
Globally Most people, on a per-capita basis, produce very little CO2. That means that they, as individuals are easily likely to double or triple the amount they generate over the next 50 years as their countries develop. of course, as individuals they will still only be producing a small fraction of what people currently do in developed countries. But globally this will mean that anything we do to cut CO2 in the developed countries will be totally overwhelmed by growth in the far larger developing world.
Even if we can convince people in the developing world that, for the sake of the planet, they need to stay poor and endure a crappy standard of living to such an extent that they do not increase their current modest CO2 emissions, Population growth alone will still overwhelm anything that we do to reduce emissions.
So, any attempt to halt, slow or reverse "Climate change" by cutting developed world CO2 emissions is simply expensive and futile virtue signalling.
If there was no harm associated to this futile expenditure then that wouldn't be too bad.
But resources are limited, and anything we spend on futile attempts to control the climate will detract from our ability to spend money on the things we will need to do to protect ourselves from the consequences of climate change.