There's no doubt that countries that were involved in the slave trade should belatedly recognise and regret their history and the suffering that slavery (and Empire and colonialism) represented. However, for any rational person to even to begin to suggest that the UK (or any other country) would be able to pay reparations on this scale, none of which any living person, or indeed any ancestor less than five generations ago, were responsible for is frankly absurd.
For instance, the article suggests (on the basis of calculations done by the Brattle Group Report on Reparations for Transatlantic Chattel Slavery, examining history going back hundreds of years - see https://en.wikipedia.org/wiki/Brattle_Group ) that Jamaica alone would be eligible for nearly US$ 10 trillion which, to paraphrase, Judge Robison helpfully suggests could be paid in instalments , eg over 10 years at $1 trillion p.a. - this would equal around $3.5 million dollars per Jamaican inhabitant, or $10 million per household.
I think the judge, Patrick Robinson, has taken leave of his senses and to be seriously suggesting this is a feasible starting point for discussion on the matter is dangerously stirring the pot of resentment. It might be useful to recall that this "leading UN" judge oversaw what many would consider a farrago of judicial nonsense in the war crimes trial against Slobodan Milosevic
Dealing with the history of slavery is a delicate and emotionally and politically charged matter. You're not going to get many sympathetic UK citizens willing to totally impoverish themselves at any time, never mind under the stresses of the country presently. They'll be more likely to seriously bridle and say "stuff you" or worse, which is not going to help anyone, least of all any Jamaican or other black person now resident in the entire Western Hemisphere.
Presumably too those of West Indian descent now residing in the UK wouldn't have to pay that reparation and could in addition claim their own $3.5 million? .