Inconvenient climate records raise big questions

Al Gore’s movie and book, “An Inconvenient Truth” convinced John Key and many other New Zealand politicians that catastrophic climate change was real and happening in their time, thanks largely to a now discredited temperature graph known as “the hockey stick”.

But now a real temperature graph using ice core data from Antarctica shows just how much the public and politicians were conned. The Law Dome ice core study has been languishing unpublished for more than a decade, and the picture below, featuring global temperatures on the vertical axis and the years in AD on the horizontal, shows modern temperatures are cooler than they were a thousand years ago.

How, you may ask, does an ice-core at -70 below in Antarctica measure global temperatures? Certain Oxygen isotopes are more prevalent in warmer climates, and less prevalent in the cold, and after adjusting for the known location scientists can establish – from when the oxygen was captured in the ice – how warm the circulating global atmosphere was at the time.

In comparison, the discredited “Hockey Stick” tries to suggest modern temperatures are hotter than ever.