Yeah, sorry about the low quality comment. But the more sincere point was, don't claims to know the global average ocean surface temperature in the 19th century

Yeah, sorry about the low quality comment. But the more sincere point was, don't claims to know the global average ocean surface temperature in the 19th century with some accuracy qualify as "extraordinary claims"? I feel uncomfortable just accepting it without a) extraordinary proof, or b) some explanation why it's actually not so extraordinary, or c) maybe error bars or uncertainty clouds on the graph?