But the doubling every year claim really only makes sense over a short period of history too. Starting from the article's 27 exabytes every 7 days in 2010, tracing back in time (halving each year), you get down to about 1 byte of information being produced in 1940.

Forecasting these kinds of relationships back to the dawn of time seems a bit tricky to me - I would guess we're really seeing something like an S curve.