I would like them to explain how there was extensive surface temperature data over the oceans, the Arctic and Antartic from 130 years ago. That data has only been available for the last 10-20 years from satellites.
Ocean going vessels have been routinely logging air (and often water) temperature, barometric pressure and general weather and ocean surface conditions for hundreds of years.
For example, here’s a site where users can transcribe logs to add to the data:
with examples of typical logs.