They announced that last month was the hottest October on record.
The problem and the hit to their credibility is they were not using accurate data and twp blogs, Watts Up With That and Climate Audit discovered the error when they were doing a detailed analysis of the GISS data.
From the Telegraph:
This was startling. Across the world there were reports of unseasonal snow and plummeting temperatures last month, from the American Great Plains to China, and from the Alps to New Zealand. China's official news agency reported that Tibet had suffered its "worst snowstorm ever". In the US, the National Oceanic and Atmospheric Administration registered 63 local snowfall records and 115 lowest-ever temperatures for the month, and ranked it as only the 70th-warmest October in 114 years.
So what explained the anomaly? GISS's computerised temperature maps seemed to show readings across a large part of Russia had been up to 10 degrees higher than normal. But when expert readers of the two leading warming-sceptic blogs, Watts Up With That and Climate Audit, began detailed analysis of the GISS data they made an astonishing discovery. The reason for the freak figures was that scores of temperature records from Russia and elsewhere were not based on October readings at all. Figures from the previous month had simply been carried over and repeated two months running.
After the blogs reported the error, GISS immediately started revising their figures and statistics.
This only made the confusion worse because, to compensate for the lowered temperatures in Russia, GISS claimed to have discovered a new "hotspot" in the Arctic - in a month when satellite images were showing Arctic sea-ice recovering so fast from its summer melt that three weeks ago it was 30 per cent more extensive than at the same time last year.
A GISS spokesman lamely explained that the reason for the error in the Russian figures was that they were obtained from another body, and that GISS did not have resources to exercise proper quality control over the data it was supplied with. This is an astonishing admission: the figures published by Dr Hansen's institute are not only one of the four data sets that the UN's Intergovernmental Panel on Climate Change (IPCC) relies on to promote its case for global warming, but they are the most widely quoted, since they consistently show higher temperatures than the others.
Worse yet, this is not the first time that Hansen’s methodology has been questioned and shown to be wrong after a major announcement.
Yet last week's latest episode is far from the first time Dr Hansen's methodology has been called in question. In 2007 he was forced by Mr Watts and Mr McIntyre to revise his published figures for US surface temperatures, to show that the hottest decade of the 20th century was not the 1990s, as he had claimed, but the 1930s.
When the world is busy trying to make determinations on what to do about global warming, it is difficult for them to make any informed judgment when the information they are receiving cannot be verified.
Hot Air's Morrissey puts this perfectly:
NASA must investigate this episode at GISS and insist on reliable production of accurate statistics. If they have scientists who can’t tell September from October and can’t recognize a cooling cycle in the Arctic, then they need new leadership at GISS, starting with Hansen. The admission from GISS that they can’t verify their source data when reaching to conclusions should embarrass scientists throughout the profession, as verification of data is absolutely necessary before reaching any conclusions. Without that, GISS may as well be studying the entrails of goats to make predictions about the future climate.
People can scream about global warming all day long, but Earth was here before we were and it will be around after we are all extinct, and cooking the books, producing flawed data to support one position or another will bring nothing at all to the table.
Hansen, Al Gore and GISS have done nothing but float large announcements, based on discredited information that we now see cannot be verified.