Many environmental organizations employ people whose sole purpose is to raise awareness about global warming. The more effective they are at convincing the public there’s an urgent problem, the more money these organizations receive in donations.

Activists are therefore the furthest thing from neutral parties. They have a right to participate in discussions about climate change, but we all need to understand that when they do so they are advancing an agenda.

Since agendas and science don’t mix, environmentalists should keep their distance from activities that are supposed to be scientific. Their mere presence undermines the integrity of the research. It casts a shadow over the data and calls into question the conclusions.

But activists have not kept their distance from the Intergovernmental Panel on Climate Change (IPCC) even though this body claims to be a scientific organization. Nor has the IPCC taken steps to safeguard its reputation by keeping a strict separation between itself and green groups.

This is perhaps best illustrated by a Greenpeace climate change publication that appeared in early 2007. The foreword to this document, which focused on New Zealand, was written by none other than Rajendra Pachauri. At the end of his remarks, beside his photograph, he is identified not as a private individual expressing private opinions but as the chairman of the IPCC.

I’ve mentioned previously that the fact that Richard Klein worked as a Greenpeace campaigner at age 23 was no impediment to the IPCC appointing him a lead author at age 25. I’ve also drawn attention to the fact that some of those who’ve served as IPCC expert reviewers are actually Greenpeace employees.

But the cozy relationship doesn’t end there. Bill Hare has been a Greenpeace spokesperson since 1992. By 2000 he was climate policy director for Greenpeace International. According to various Greenpeace blog posts he is “a legend” in that organization, served as its chief climate negotiator in 2007, and remains a chief policy advisor. Yet none of this has prevented him from being nominated – and chosen – to fill senior IPCC roles.

In 2000 policy director Hare served as an expert reviewer for an influential IPCC emissions scenarios document. When the 2007 edition of the climate bible was released, we learned that he’d served as a lead author, that he’d been an expert reviewer for 2 out of 3 sections of the report (see here and here), and that he was one of a select group of only 40 people who comprised the “core writing team” for the important Synthesis Report.

Hare has once again been appointed a lead author for the upcoming version of the climate bible, expected to be released in 2013 (see p. 8 of this 27-page PDF).

It’s worth noting that the IPCC is less-than-candid about his Greenpeace ties. The 2007 climate bible says he’s affiliated with the Potsdam Institute for Climate Impact Research in Germany. When the IPCC announced, last June, the list of authors for the version of the climate bible currently in progress the Potsdam Institute was once again used as cover. Since Hare is, in fact, a visiting researcher at the institute the IPCC hasn’t lied.

But imagine you’re an accident victim on the side of the road. You’re told not to worry, that the person who’s going to remain with you until the ambulance arrives is trained in first aid. What you aren’t told is that they’re also a vampire and that the blood seeping from your leg will be difficult for them to resist.

In 2009 EcoEquity, an activist think tank, observed that both Hare and a person named Malte have both “long been key members of the Greenpeace International climate team.” Indeed, Malte Meinshausen‘s Greenpeace ties stretch back to June 2001 when he and Hare co-authored a Greenpeace analysis related to the Kyoto Protocol. Throughout 2002 and 2003 Meinshausen’s name, often accompanied by a Greenpeace e-mail address, appeared on a number of Greenpeace statements and press releases (see here, here, and here).

But these facts did not prevent him from being recruited as a contributing author to not one, not two, but three chapters of the 2007 climate bible. Like Klein, above, Meinshausen’s participation is yet more proof that some IPCC authors are anything but world-class experts at the height of their careers. Meinshausen only received his doctorate in 2005.

A number of passages in the 2007 climate bible blandly cite research papers authored by Hare and Meinshausen as though it’s immaterial that they are Greenpeace personnel (see here and here, for example). Indeed, the IPCC goes so far as to reprint a graph that first appeared in a paper for which these two men are the sole authors.

And people wonder why the IPCC’s reputation has sunk so low.

.