Gun control advocates point out that taking the guns away will stop the shootings; gun rights advocates argue guns aren't really to blame.
Pearl's own illustrative example is a house fire: a match (or some other ignition) is both necessary and sufficient, oxygen in the air is necessary (no oxygen no fire) but not sufficient (just adding oxygen doesn't start a fire). That includes an assumption that oxygen is 'normal', present whether or not the match is (thus enabling the match to be sufficient, because we can assume the oxygen is there).
Are guns like oxygen? For a lot of the US, yes, in being ubiquitous, considered normal, and mostly not killing people. Removing oxygen to prevent fires is usually overkill, and they would say removing guns is too.
Other modern crises:
* greenhouse gases are reasonably necessary and sufficient for global warming. (No gases, no warming; adding greenhouses gases to an 1800 AD background suffices to cause warming.) (As a side note, Pearl points out that climate models allow climate scientists to generate counterfactual 'data' quite easily, by tweaking model parameters.)
* cars and deaths: cars are necessary for 40,000 dead Americans a year (no cars, no such deaths... alternative transport modes aren't nearly so dangerous) and sufficient (adding cars, or rather a car-oriented and -dependent culture is the main reason we have the deaths).
 Japan actually has 3/4 as many cars per capita as the US, but 1/3 as many road fatalities per capita; the cars are used less, as well as being smaller and slower in common use. Many fewer deaths per vehicle too, but similar deaths per vehicle-km.
See the DW comments at https://mindstalk.dreamwidth.org/532626.html#comments