And who is GBN?:

Peter Schwartz, futurist and business strategist; author of The Art of the Long View, When Good Companies Do Bad Things, and The Long Boom; former head of scenario planning at Royal Dutch/Shell in London, and director of the Strategic Environment Center at SRI International

Jay Ogilvy, author of Living Without a Goal and China's Futures, professor of philosophy at Yale and Williams, and past head of SRI's Values and Lifestyles research

Napier Collyns, networker extraordinaire, a 30-year veteran of Royal Dutch/Shell, responsible for planning, public affairs and human resources

Stewart Brand, writer, futurist, and inventor of ideas; author of The Clock of the Long Now, How Buildings Learn, The Media Lab, and originator of The Long Now Foundation, the Whole Earth Catalog, CoEvolution Quarterly, and The WELL computer network

Lawrence Wilkinson, multi-media innovator; current vice-chair of Oxygen Media and former president of Colossal Pictures

Notice the lack of climatologists, meteorologists, or scientists of any sort.

Some more background.

It always is a good idea to consider the sources for reports like these.