Acid rain became a publicly known problem in the 1980s and 1990s. Industrial pollution in the form of sulphur dioxide, SO₂, would dissolve in atmospheric water to produce sulphuric or sulphurous acid. This falls in rain away from the pollution-causing industry and kills forests.

The solution was not regulation, which no politician would support, but a quota of how much could be produced and selling permission to produce SO₂ up to that limit. Those permits to pollute could themselves be sold.

Trading in SO₂ permits began in 1995. It was considered a huge success in that SO₂ pollution was cut by half.

So how about introducing war quotas?

That is, the UN could sell licences to kill people, be it troops or civilians. Determine how many people are killed per year globally, and provide licences to kill people – initially say 90% of that number – and reduce the quote each year by 10%.

Year 1 – 100%
Year 2 – 90%
Year 3 – 81%
Year 4 – 72.9%
Year 5 – 65.6%
Year 6 – 59%
Year 7 – 53%
Year 8 – 47.8%

So after just 8 years we could reduce deaths by government-sanctioned war by half!

The licences would be for sale on the open market to despots or global police according to who can afford them. If democracies are willing to fund killing people, then fine, they can. Otherwise the despots get to do so, if they can afford to raise the necessary funds.

It would also allow an alternative way of prosecution major organised drugs crime organisations, international pirates, the Mafia, and so on. Provided they pay their way and can buy the licences on the open market, then they can continue in business

If it is OK and ethical for governments to kill people by war but we don’t like it, then why can’t we take a leaf from the environmental lobbyists book and introduce quotas to reduce the unwanted behaviour – killing people with bullets and bombs – to a more acceptable level?