Joseph Romm, chief blogger at Climate Progress, writes an open letter to James Hansen, the most important, most heard voice of science in the climate debate. ~If you’re right about the risks, your recommendations are nowhere nearly bold enough.~

To James Hansen (and his fellow 350 ppm-ers):

You make a compelling case we must ultimately return atmospheric concentrations of carbon dioxide to 350 parts per million to avoid catastrophic climate impacts (see “Stabilize at 350 ppm or risk ice-free planet, warn NASA, Yale, Sheffield, Versailles, Boston et al“).

But you have made an uncompelling case about how President-elect Obama should go about achieving 350 ppm in your new draft essay Tell Barack Obama the Truth — The Whole Truth and in previous essays (see here). You are, for instance, overly dismissive of cap-and-trade and overly enamored of a carbon tax, when, in fact, neither holds any prospect whatsoever of achieving your goal. Your discussion of as-yet non-commercial 4th generation nuclear technologies is equally off the point, as we’ll see.

If the truth is that we must have a target of 350 ppm, then you must be equally truthful in insisting on national and international policies that could achieve that goal. So far, you haven’t. Nobody has.

Er, pretty scary stuff….