70 million a year -- that it's perhaps not surprising that the vast scale of our geological impact is yet to sink in. But it should not be a surprise because the realisation is not new. Undercover geological agents "Most interesting of all, perhaps, is the question whether man, by his prodigious combustion of coal ... is producing more [carbon dioxide] than can be eliminated by ordinary natural processes. If this production is excessive, the result eventually may be an unwelcome change in his atmospheric surroundings." One can imagine our shock jocks rolling their eyes at this quote, proclaiming yet more "warmist" propaganda as part of an organised climate science "swindle" hell bent on undermining the modern industrial world, or securing more government largesse. But it only sounds like it might have been written in recent times because I have altered the wording to fit the modern context. In reality, the author did not use "carbon dioxide". Rather he used "carbonic acid", a term in vogue generations ago, and a dead giveaway as to its ancestry. And I bet our shock jocks would never guess it originates from one of the most celebrated geologists of his time. The quote is from Arthur Woodward, "keeper of geology in the British Museum", Fellow of the Royal Society, President of the Royal Linnean society. Woodward's comments appeared as preface to a classic geological text by Robert Sherlock -- "Man as a geological agent" -- published in 1923. Intriguingly, Woodward's quote followed with the