Is this a not so cryptic message for 2016? The cliff? That's what I've been looking for since September 11, 2001. The caption seems to hint '2016' is the year.
Remember, when you sum every number 1-63, it totals 2016.
Below was his cartoon days before the Brexit vote.
Remain = 33
Brexit = 33 (Before the vote I had no idea the word was 'leave')
Notice the writing on the 'Brexit' box.
137, 33rd Prime Number
Let's decode the illustrators name.
Martin = 4+1+9+2+9+5 = 30
Rowson = 9+6+5+1+6+5 = 32/41
Martin Rowson = 62/71
Martin = 13+1+18+20+9+14 = 75
Rowson = 18+15+23+19+15+14 = 104
Martin Rowson = 179 (179, 41st Prime Number)