- January: The UK Met Office predicts that 2007 is likely to be the warmest year on record globally.
- February: The IPCC release the summary of their 4th Assessment Report (AR4), well before the main body of the report, leading to suspicions that the conclusions were decided upon before the main work was done. The summary contains a basic arithmetic error, that the IPCC has never acknowledged.
- August: Blogger and amateur climate scientist Steve McIntyre finds an error in NASA's temperature records for the USA. After the error is corrected, 1934, not 1998, is the warmest year in the USA. Instead of politely acknowledging the error, NASA's James Hansen issues an incoherent rant "The Real Deal: Usufruct & the Gorilla" that does not even mention McIntyre, but refers to his critics as contrarians and court jesters.
- September: Hansen carries out another of his "adjustments" of the temperature record for the USA. After this adjustment, the 1880's have suddenly got cooler by about 0.1 degrees, and 1934 and 1998 now tie for warmest year.
- November: Official release of the full IPCC AR4 report.
- December: It turns out that 2007 was cooler than any of the 6 previous years, contrary to the Met Office prediction made in January.
January: the Met Office predicts that 2008 will be a 'top-ten' year.
August: Lewis Pugh attempts to Kayak from Spitzbergen to the North Pole, "to raise awareness of how global warming has melted the ice sheet", as enthusiastically reported by the BBC. After a few days he gets stuck in the ice, having got about 1/10 of the way. Curiously, the BBC and the rest of the mainstream media do not report this fact.
- March: A Gallup Poll shows that increasing numbers (41%, up from 35% last year) think that global warming is exaggerated.
April: A Rasmussen opinion poll shows that only 34% of US voters now believe that global warming is caused by human activity, down from 47% one year ago.
- April: Research by the British Antarctic Survey shows that the Antarctic ice extent is increasing. German scientists find that the ice thickness in the arctic is greater than in previous years.
- November: Hundreds of emails to and from Phil Jones, head of the Climatic Research Unit, are posted on the web, revealing attempts to distort the data, refusal to release data, and attempts to ensure certain papers do not get into the IPCC reports. The emails vindicate what sceptics have been saying for years. Jones steps down pending a review.
- November: A second release of "climategate" emails occurs, two yeas after the first.
- February: Climate scientist Peter Gleick fraudulently obtains documents from the Heartland Institute.