claim: Since the hockey stick paper in 1998, there have been a number of proxy studies analysing a variety of different sources including corals, stalagmites, tree rings, boreholes and ice cores.
evidence: On the day of publication, the ExxonMobil funded lobbying website Tech Central Station issued a press release headed "TCS Newsflash: Important Global Warming Study Audited – Numerous Errors Found; New Research Reveals the UN IPCC 'Hockey Stick' Theory of Climate Change is Flawed" announcing that "Canadian business executive Stephen McIntyre and economist Ross McKitrick have presented more evidence that the 20th century wasn't the warmest on record".