We welcome debate about the ethics of science prompted by the language of some of the hacked e-mails from the UK Climatic Research Unit (Nature 462, 545; 2009). Rightly or not, this has created concerns about the scientific process. But it is critical to point out that no grounds have arisen to doubt the validity of the thermometer-based temperature record since 1850.

Both the detection of climate change and its attribution to human activities rely on the thermometer-based temperature record (compiled by the Climatic Research Unit and other institutions). They do not rely on proxy reconstructions of temperature over the past millennium, which are based on indirect evidence such as tree rings. Reconstructions contribute less to our understanding of climate than the thermometer record because of uncertainty both in these reconstructions and in the drivers of climate change before the twentieth century.

Unfortunately, the mainstream media have confused the two. The thermometer record shows unequivocally that Earth is warming, and provides the main evidence that this is caused by human activity. This crucial record remains unchallenged.

Commentators have suggested that the e-mails disclose a 'team mentality' among prominent climate scientists. Some people may have gone too far in promoting particular viewpoints, so an independent enquiry and open discussion should help to re-establish public confidence. However, it is absurd to suggest that there is some kind of global conspiracy involving all climate scientists.

We and our colleagues have worked with the scientists at the centre of this controversy. We have examined, used and at times criticized their data and results — just as they, at times, have criticized ours. Our disagreements have no bearing on our respect for other aspects of their work.

See also Climate e-mails: lack of data sharing is a real concern.