The people on the street need to be wearing sunscreen.
without sunscreen, the people in the street will all get sunburned.
Just because people need sunscreen doesn't mean they would necessarily get sunburned without it. People need sunscreen to protect from harmful rays long before they would get sunburned.
exists p1 x1 x2 x3.(Topic(x2,p1) & exists e1 x4.(Theme(e1,x4) & Actor(e1,x2) & v_wear(e1) & n_sunscreen(x4)) & n_need(x2) & of(x2,x3) & n_street(x3) & n_people(x1) & a_topic(x1) & on(x1,x2))
exists e1 p1 s1 x1 x2 x3.(n_street(x2) & n_people(x1) & without(e1,x3) & n_sunscreen(x3) & a_all(s1) & Manner(e1,s1) & exists e2.(Theme(e2,x1) & v_sunburn(e2)) & Topic(e1,p1) & Actor(e1,x1) & v_get(e1) & in(x1,x2))