They don’t call it “land-surface warming,” and they don’t call it “oceans-only warming.”
It’s called “global warming” for a reason, and one of the principal reasons is that climate change takes into account not only the approximately 29 percent of the Earth’s surface that consists of land, our continents, but also the 71 percent comprised of oceans.
In this month”s “This is Not Cool” video debriefing, independent videographer and climate analyst Peter Sinclair, of Midland, MI, presents and interviews an all-star cast of climate scientists helping tell what one — Ben Santer of Lawrence Livermore Laboratory — describes as “an internally physically consistent story” based on a wide body of scientific evidence on climate change.
As Columbia University scientist James Hansen explains in the video, global temperatures over the past decade-plus have increased about 1/10th of a degree, versus the 2/10ths of a degree increase in the previous decade. “But that’s just natural variability. There’s no reason to be surprised by that at all.”
Such “hiatus periods” have occurred in the past and are expected to again in the future, the National Center for Atmospheric Research’s Jerry Meehl explains. The increased heat, he says, is going into the ocean, which NASA Jet Propulsion Laboratory scientist Josh Willis calls “our most accurate thermometer for measuring climate change.”
The video comes at a time of confusion in some quarters about just how sensitive the global climate is to an increase in atmospheric carbon dioxide concentrations — and just how significant the resulting temperature increases are from a practical standpoint — and amidst widespread scientific curiosity and inquiry to explain an observed slow-down in global temperature over the past 15 years or so.
Those issues are expected to be at the forefront of coming points emphasized by parties interested in debunking the science as represented by the upcoming releases of IPCC “AR 5” (Assessment Report 5) studies, due to begin being released at the end of September.
Scientists from a diverse collection of academic and government research institutions explain in Sinclair’s video that, NASA/JPL’s Willis says, sea-level rise over the past 20 years has shown an “incredibly steady background trend” that can be explained only by human-caused greenhouse gas emissions. Several point out that more than 90 percent of increasing global heat resulting from GHGs is taken-in by the oceans, and rising ocean temperatures — and resulting sea-level rise, particularly in the deepest ocean depths — are testimony to that continued warming.
So, what about the whole current debate about global warming having “ended” or at least “slowed down” over the past decade-and-a-half? The whole issue of the warming “pause” or, more accurately, slow-down, and its practical implications and significance will be subjects of several upcoming Yale Forum postings — including both new work and encore repostings of two well-received earlier explanations — and will be the subject explored also in Sinclair’s next “This is Not Cool” video, to be posted around the end of the month.