Youth versus Obama: Dr. Hansen’s Testimony Against the Government

35.    We can turn now to Chart 8.

36.    Here, we summarize the average global surface temperature record of the last 65 million years.  This record is based on high-resolution ice core data covering the most recent several hundred thousand years, and ocean cores on time scales of millions of years.  It provides us with insight as to global temperature sensitivity to external forcings such as added CO2, and sea level sensitivity to global temperature.  It also provides quantitative information about so-called “slow” feedback processes – such as melting ice sheets and lessened surface reflectivity attributable to darker surfaces resulting from melting ice sheets and reduced area of ice.

37.   Several relevant conclusions can be drawn.  First, the mechanisms that account for the relatively rapid oscillations between cold and warm climates were the same as those operating today.  Those past climate oscillations were initiated not by fossil fuel burning, but by slow insolation changes attributable to perturbations of Earth’s orbit and spin axis tilt.  However, the mechanisms that caused these historical climate changes to be so large were two powerful amplifying feedbacks: the planet’s surface albedo (its reflectivity, literally its whiteness) and atmospheric CO2.

38.   Second, the longer paleoclimate record shows that warming coincident with atmospheric CO2 concentrations as low as 450 ppm may have been enough to melt most of Antarctica. Global fossil fuel emissions – towards which, as I noted above, our nation has contributed more than any other – have already driven up the atmospheric CO2 concentration to approximately 400 ppm – up from 280 ppm of the preindustrial era.

39.    I conclude that the present level of CO2 and its warming, both realized and latent, is already in the dangerous zone.  Indeed, we are now in a period of overshoot, with early consequences that are already highly threatening and that will rise to unbearable unless action is taken without delay to restore energy balance at a lower atmospheric CO2 amount.  We can turn now to a brief review of the increasingly unacceptable, but still avoidable, consequences.
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85.   Simply put:  Our government’s persistent permitting and underwriting of fossil fuel projects serves now to further disrupt the favorable climate system that to date enabled human civilization to develop.  In order to preserve a viable climate system, our use of fossil fuels must be phased out as rapidly as is feasible.  Only government can ensure this will be done. Instead, our government seeks approval for permitting of fossil fuel projects that would slam shut the narrowing window of opportunity to stabilize climate and ensure a hospitable climate and planet for young people and future generations.  These projects only allow our government to shirk its duty.  Our government’s permitting of additional, new, or renewed fossil fuel projects is entirely antithetical to its fundamental responsibility to our children and their posterity.  Their fundamental rights now hang in the balance.

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