First it was the coming ice age, then it was global warming, now we’re back to the coming ice age...
And it the same coming ice age, based on the same effects. Only we know even more about them now than we did before.
It's coming, the Big One, not just "Hans Brinker and the Silver Skates"(Ice on the Dutch canal networks) But a real Ice Age, big glaciers of the sort that gave us the prairie potholes and the Great Lakes. How soon? Well we're overdue already, but any millennium now, maybe any century.
(The appearance of more, "high frequency" variation in more recent data is due to higher sampling rate, that is more closely spaced samples)