The utterances of James Hansen, the Nasa climatologist who is widely credited with being the first scientist to successfully megaphone the risks of climate change to the wider world back in the 1980s, always attract attention.

He is nothing less than a Marmite figure within the climate debate; sceptics hate him for his sometimes emotive political advocacy, whereas advocates for action on climate change respect his scientific authority and the role he has played in spelling out to our political masters the potential dangers of climate change.

So a new draft paper , co-authored with colleagues at the NASA Goddard Institute for Space Studies in New York, which has just been submitted to the journal Reviews of Geophysics, is sure to get noticed. Particularly so because it tackles head on the unique pressures facing climate science at the moment, namely, calls from a doubting public and media for climatologists to be more transparent about how they arrive at their conclusions.

For anyone interested in how climatologists collate and interpret the all-important average global temperature datasets the paper (which is yet to be peer reviewed) is an illuminating read, but perhaps the most interesting section for a wider audience – which Hansen admits "might not survive depending on the advice of the [journal's] editors" – is the final concluding section (pdf):

Human-made climate change has become an issue of surpassing importance to humanity, and global warming is the first order manifestation of increasing greenhouse gases that are predicted to drive climate change. Thus it is understandable that analyses of ongoing global temperature change are now subject to increasing scrutiny and criticisms that are different than would occur for a purely scientific problem.
Our comments here about communication of this climate change science to the public are our opinion. Other people may have quite different opinions. We offer our opinion because it seems inappropriate to ignore the vast range of claims appearing in the media and in hopes that open discussion of these matters may help people distinguish the reality of global change sooner than would otherwise be the case. However these comments, even though based on experience over a few decades, are only opinion. Our primary contribution is quantitative results discussed in the numbered paragraphs below. [Leo: certainly worth reading, but too long to include here on this blog.]
Communication of the status of global warming to the public has always been hampered by weather variability. Lay people's perception tends to be strongly influenced by the latest local fluctuation. This difficulty can be alleviated by stressing the need to focus on the frequency and magnitude of warm and cold anomalies, which change noticeably on decadal time scales as global warming increases.
A greater obstacle to public communication has arisen with the politicization of reporting of global warming, a perhaps inevitable consequence of the economic and social implications of efforts required to alter the course of human-made climate change. We have the impression that the effect of politicization on communication of the science is aggravated by the fact that much of the media is owned by or strongly influenced by special economic interests.
The task of alleviating the communication obstacle posed by politicization is formidable. The difficulty is compounded by continual attacks on the credibility of scientists. Polls indicate that the attacks have been effective in causing many members of the public to doubt the reality of global warming.
Given this situation, the best hope may be repeated clear description of the science and passage of sufficient time to confirm validity of the description. A problem with that prescription is the danger that the climate system could pass tipping points that cause major climate changes to proceed largely out of humanity's control [Hansen et al., 2008]. Yet continuation of this approach seems to be essential for the sake of minimizing the degree of inevitable climate change, even while other ways are sought to draw attention to the dangers of continued greenhouse gas increases.
One lesson we have learned is that making our global data analysis immediately available, with data use by ourselves and others helping to reveal flaws in the input data, has a practical disadvantage: it allows any data flaws to be interpreted and misrepresented as machinations. Yet the data are too useful for scientific studies to be kept under wraps, so we will continue to make the data available on a monthly basis. But we are making special efforts to make the process as transparent as possible, including availability of the computer program that does the analysis, the data that goes into the analysis (also available from original sources), and detailed definition of urban adjustment of meteorological station data.

There is, of course, plenty of urgent discussion going on at the moment about how to better communicate the climate change message following the events of recent months, such as the hacked/stolen/leaked/[for the purposes of avoiding a tedious debate, insert your own term] UEA emails, which have caused public confidence in climate science to nose dive. For example, Bob Ward was writing about just this issue in New Scientist last week.

But it is still interesting to hear the thoughts of one of climate science's leading voices, particularly one who has never shied away from implicitly politicising the communication of the science via his often strident advocacy of certain solutions.

Hansen lays out the efforts he has made to be transparent and open with his data. Advocating this approach despite the danger that flaws could be "interpreted and misrepresented as machinations" could be taken as an implicit criticism of the climate scientists at the University of East Anglia. They have come under attack for discussions in the stolen emails that were published in November which suggested they were withholding information from their critics.

Does this mean that Hansen will now temper his campaigning role and solely stick to "doing the science" though? After all, the paper also states that "our principal task remains the scientific one; trying to describe with increasing clarity and insight the global temperature change that is occurring".

One thing that Hansen and other climatologists will be desperately trying to communicate - as he does in this paper – is that 2010 is currently on course to challenge for the title of the hottest year on record, despite popular perception to the contrary following a cold winter in much of the northern hemisphere. As the paper states:

The 12-month running mean global temperature in the GISS analysis has reached a new record in 2010. The new record temperature in 2010 is particularly meaningful because it occurs when the recent minimum of solar irradiance is having its maximum cooling effect. At the time of this writing (May 2010) the tropical Pacific Ocean has changed from El Nino conditions to ENSO-neutral and is likely headed into the cool La Nina phase of the Southern Oscillation. The 12-month running mean global temperature may continue to rise for a few more months before the ENSO change causes the next decline. It is likely that global temperature for calendar year 2010 will exceed the 2005 record, but that is not certain if a deep La Nina develops quickly.

As Hansen acknowledges, the race is now on to present news such as this in a dispassionate, transparent, authoritative manner to a public that is also at the same time being aggressively courted by a noisy, anarchic blogosphere and a politicised media who are repeatedly urging them to shoot the messenger.

Yes, to a certain degree the messengers have conspired to shoot themselves in the foot of late, but what Hansen and his colleagues are now urgently trying to do is reboot the climate debate and start afresh. The message seems to be: if it means going back to basics and starting from the beginning all over again, then so be it.