Who warned of ‘climate instability’ in 1988? The Saturday quiz

The questions

1 How many times does the sun rise each year at the north pole?
2 Which board game inspired the creation of QR codes?
3 Five of the six cataracts of the Nile are in which country?
4 In what decade did Germany print a 100-trillion Mark note?
5 Who warned of a “global heat trap” and “climate instability” in 1988?
6 Which rhythm section had the surnames Dunbar and Shakespeare?
7 Free the Weatherfield One was a campaign to liberate whom?
8 What was the main language of the Inca empire?
What links:
9 Barringer, US; Chicxulub, Mexico; Vredefort, South Africa; Wolfe Creek, Australia?
10 Smokin’ Joe; Fighting Marine; Neon Leon; Easton Assassin?
11 American Legion; Theodor Escherich; Daniel Salmon; staff; twisted berry?
12 Paul McCartney and Ringo Starr; Larry Bell, Dion DiMucci and Bob Dylan?
13 Bass beer; bleaching allowed; major seventh chord; youth hostel?
14 Cole Allen; Thomas Crooks; Ryan Routh?
15 1558 (25); 1689 (26); 1702 (37); 1837 (18); 1952 (25)?

Treading water over the Nile clue? Photograph: Adam Jones/Getty Images

The answers

1 Once.
2 Go.
3 Sudan.
4 1920s.
5 Margaret Thatcher.
6 Sly and Robbie.
7 Deirdre Rachid (in Coronation Street).
8 Quechua.
9 Meteor/asteroid impact craters.
10 Nicknames of boxers who defeated Muhammad Ali: Joe Frazier; Ken Norton; Leon Spinks; Larry Holmes (Trevor Berbick didn’t have one).
11 Etymology of types of bacteria: legionella; E coli; salmonella; bacillus (Latin); streptococcus (Greek).
12 People on Beatles’ Sgt Pepper album cover who are still alive.
13 Represented by a triangle symbol: brewery logo; laundry label; jazz notation; on OS map.
14 Alleged attempted assassins of Donald Trump.
15 Queens: accession year (age on accession): Elizabeth I; Mary II; Anne; Victoria; Elizabeth II.