Updated

U.S. Senator John Kerry and Brice Lalonde, the French-born coordinator of the United Nations Rio + 20 summit conference on sustainable development ,which got under way this week, have a lot in common. Among other things, they are first cousins, a fact widely reported when Kerry ran for the U.S. presidency in 2004.

And now both of them are involved in pressing for the success of a radical U.N. agenda for climate change that seems to be faltering in the face of global economic crisis.

Lalonde, 65, and Kerry, 68, share maternal grandparents; Lalonde's branch of the family bought their French estate in the 1920s and, according to news reports he and the future Massachusetts senator played together as children.

Both were involved in cutting-edge political causes in their youth, Kerry as a decorated U.S. Navy officer turned vociferous anti-war spokesman in 1971, and Lalonde as leader of the French university student’s union in 1968, a year of near-revolution in France, and subsequently as a militant supporter of Greenpeace.

Both later ran unsuccessfully for President in their respective countries -- Lalonde in 1981 -- and both went on to further high office, with Lalonde serving as France's environment minister from 1991 to 1992, and subsequently as French climate change ambassador under President Nicolas Sarkozy.

Both men are now deeply embroiled in pushing for the U.N.-sponsored  agenda of radical economic reorganization to combat climate change: Lalonde as one of Rio + 20's top organizers, and Kerry, as the self-described "leading advocate in the United States Senate for action to address international climate change,"  who delivered a thunderous, stem-winding speech against climate-change "denial" and in support of Rio + 20 on Tuesday, just before the Brazil meeting began.

Yet remarkably, neither Senator Kerry's office, the U.S. State Department, nor U.N. staff working with Lalonde at Rio + 20 is eager, or even willing, to discuss the close kinship between the two men, whether they have ever discussed their common enthusiasms in the walk-up to Rio + 20, or how the relationship may have colored the diplomatic discussions around the Rio + 20 conference.

"I apologize, but I have no information on Mr. Lalonde's private life and I am not able to answer these questions," a U.N. spokesman told Fox News, in response to queries about any contact or conversations between the two men in the walkup to Rio + 20, and whether Lalonde had ever mentioned the kinship connection to U.S. officials during his Rio + 20 duties.

After acknowledging the queries, Kerry's office had given no reply at all to similar questions from Fox News regarding contacts between the two men before this article was published.

"Scheduling demands are tight.  I'm sorry, we're not going to be able to get anyone for this question this week," a State Department spokesman told Fox News in response to general questions about the extent to which the Kerry-Lalonde relationship had come up in any conversations between U.S. officials, including Secretary of State Hillary Clinton, and Lalonde.

All of that reticence seemed out of character, when Lalonde and Kerry -- not to mention the Obama Administration -- have been advocating for the climate change agenda as hard, or harder than ever, and especially in the context of Rio + 20, which currently shows signs of faltering over issues such as the transfer of trillions of dollars to developing nations over decades for "green economy" objectives.

In his nearly hour-long speech on Tuesday Kerry declared that the "danger we face could not be more real,"  decried a "conspiracy of silence" against the climate change threat, and described a world where "ice caps are melting. Seas are rising. Deserts are spreading. Storms are more frequent, more violent and more destructive. And pollution, famine and natural disasters are killing millions of people every year."

"Accelerating the transition to a new energy paradigm is the most important single step the world can take to reduce the threat of climate change," he summarized. "And Rio is as good a place as any to make that happen."

No mention, however, of the fact that his first cousin was equally well placed in that effort.