From the article:
The one other several-year period during the time frame of modern instrumental records with an estimated loss of hemispheric sea ice coverage comparably as rapid as [the current one was] in the mid-1970s. Calculations based on a variety of datasets [..] show rates of decrease of ∼600,000 km2/y for the 4 y from the start of 1973 to the start of 1977 and for the 3-y subset from the start of 1974 to the start of 1977
The concluding remark is helpful to reproduce in full:
I hope that the 40-y record discussed in this paper will encourage further studies into the atmospheric and oceanic conditions that could have led to the extremely rapid 2014–2017 decline of the Antarctic sea ice cover, the comparably rapid decline in the mid-1970s, and the uneven but overall gradual increases in Antarctic sea ice coverage in the intervening decades. More broadly, the environmental datasets may be nearing the point where they are long enough and rich enough to enable the linking of several of the modes and dipoles and oscillations now spoken of separately, just as the El Niño and Southern Oscillation phenomena were linked together years ago as ENSO; once that further linkage happens, the understanding of Earth’s very interconnected climate system, including the sea ice cover, could be markedly enhanced.
Are we accounting for positioning and skewing of the sun (on it's natural cycle)?
So much more goes into temperature regulation than simply "carbon emissions", if we were to realistically tackle an environmental disaster I would point to the plastic waste in the ocean and the fish farms.
Does that mean over 40 years ago it had an even lower area or that they are at all time lows (as far as we can tell)? Could account for why my grandparents are skeptical, they're like "yeah, yeah, this has all happened before, environmental political fads come and go..."