Scientists may have hugely underestimated the extent of global warming because temperature readings from southern hemisphere seas were inaccurate.
It's kind of sad how some people took the recent findings that there is less atmospheric warming than expected over the last few decades (due to the oceans absorbing and releasing heat in cycles) to mean that global warming was overhyped, that climate change is actually happening more slowly than we expected. They ignore, of course, the fact that we also found more heat being trapped by oceans, and they ignore (of course) the fact that most life is in the oceans and that the oceans are the greatest regulator and driver of global climate.
It's the same story with environmentalism in general. People focus way too much on the landmass and atmosphere and seem to ignore the ocean. Half the coral that was present in the oceans 50 years ago is gone. 90% of the large fishes are gone. The coasts are in shambles. We really need to do more.