That's exactly the sort of data that the IPCC does not seem able to refute with observed data.
It's interesting to see the article claim that "CO2 levels aren’t declining". I've seen data produced by the Mauna Loa observatory interpreted by some scientists to prove this point, whereas other scientists have used exactly the same data to prove the opposite! Yet the data only goes back to 1959, which is not long enough to be meaningful when it is being compared to the Vostok ice core.