Connolley lets Newsweek off way too easy by calling the judgment "self-serving". The 1975 article says:
the earth’s climate seems to be cooling down. Meteorologists disagree about the cause and extent of the cooling trend, as well as over its specific impact on local weather conditions. But they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century.
That was a demonstrably wrong assessment of what scientists thought at the time, but has been used endlessly by idiot denialists ever since to argue against the significance of actual scientific consensus.
So in 1975, Newsweek couldn't do accurate journalism research. Now, they can't even read their own article closely. I don't know how good its journalism has been on climate change in the intervening decades, but Newsweek has bookended its work with incompetence.
UPDATE: Working Newsweek link to article here (the one at RealClimate died).