Here are a selection of quotes from the emails stolen from computers at the University of East Anglia. Many involve Phil Jones, head of the university's Climatic Research Unit.
From: Phil Jones. To: Many. Nov 16, 1999
"I've just completed Mike's Nature [the science journal] trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith's to hide the decline."
Critics cite this as evidence that data was manipulated to mask the fact that global temperatures are falling. Prof Jones claims the meaning of "trick" has been misinterpreted
From Phil Jones To: Michael Mann (Pennsylvania State University). July 8, 2004
"I can't see either of these papers being in the next IPCC report. Kevin and I will keep them out somehow — even if we have to redefine what the peer-review literature is!"
The IPCC is the UN body charged with monitoring climate change. The scientists did not want it to consider studies that challenge the view that global warming is genuine and man-made.
From: Kevin Trenberth (US National Center for Atmospheric Research). To: Michael Mann. Oct 12, 2009
"The fact is that we can't account for the lack of warming at the moment and it is a travesty that we can't... Our observing system is inadequate"
Prof Trenberth appears to accept a key argument of global warming sceptics - that there is no evidence temperatures have increased over the past 10 years.
From: Phil Jones. To: Many. March 11, 2003
“I will be emailing the journal to tell them I’m having nothing more to do with it until they rid themselves of this troublesome editor.”
Prof Jones appears to be lobbying for the dismissal of the editor of Climate Research, a scientific journal that published papers downplaying climate change.
From Phil Jones. To: Michael Mann. Date: May 29, 2008
"Can you delete any emails you may have had with Keith re AR4? Keith will do likewise."
Climate change sceptics tried to use Freedom of Information laws to obtain raw climate data submitted to an IPCC report known as AR4. The scientists did not want their email exchanges about the data to be made public.
From: Michael Mann. To: Phil Jones and Gabi Hegerl (University of Edinburgh). Date: Aug 10, 2004
"Phil and I are likely to have to respond to more crap criticisms from the idiots in the near future."
The scientists make no attempt to hide their disdain for climate change sceptics who request more information about their work.