If someone talks about "remaining trust in climate science" is because he doesn't believe any data and looks for any miningless thing to try to not believe it like your comments about the graph

And it took just 30 seconds of search to know why the data starts in 1978[0]:

> Useful satellite data concerning sea ice began in late 1978 with the launch of NASA's Scanning Multichannel Microwave Radiometer (SMMR) satellite.

[0]: https://nsidc.org/cryosphere/quickfacts/seaice.html