Yes, because the supply of proxy variables (or as they call it, "climate indicators") is endless: sea level (measured in a convenient spot), surface temperature, only inter-ocean comparison, comparison of derivatives ("Oceans are warming twice as fast than the 1960s"), tail measures instead of averages ("sea level extremes"), ...
It's almost as if 70% of the planet was covered by oceans.
The oceans are also on the list.
Yes, because the supply of proxy variables (or as they call it, "climate indicators") is endless: sea level (measured in a convenient spot), surface temperature, only inter-ocean comparison, comparison of derivatives ("Oceans are warming twice as fast than the 1960s"), tail measures instead of averages ("sea level extremes"), ...