What Stockman then wanted to know is, why isn’t “global - TopicsExpress

What Stockman then wanted to know is, why isn’t “global wobbling” included in climate modelings? “How can you take an element which you give to the credit for the collapse of global freezing and into global warming but leave it out of your models?” Stockman asked. “I’m a little puzzled because we still don’t have metrics of how to determine global wobbling.” In the video, Holdren explains that global wobbling happens so slowly — on timescales of 22,000 years, 44,000 years, and 100,000 years — that it doesn’t impact the comparatively fast impacts of climate change. In fact, Holdren says because of previous wobbling, we should be in a cooling period as we speak. “But the warming inflicted by human activities has overwhelmed the effect of global wobbling,” he said. Stockman also said he “can’t get answers” to how long it would take for the sea level to rise two feet. “Think about it, if your ice cube melts in your glass, it doesn’t overflow. It’s displacement. This is some of the things that they’re talking about that mathematically and scientifically don’t make sense.” Holdren wasn’t given a chance to answer this question, but the answer is pretty simple. Stockman seems to be forgetting that not all melting ice is already in the sea. Melting land ice — glaciers, ice sheets, ice caps, and permafrost — are the major contributors to global sea-level rise as their water flows into the ocean. And even though melting sea ice doesn’t directly contribute to sea level rise, it does cause ocean temperatures to rise. This causes the ocean to expand and rise — a big component of sea level rise — and the added heat can ultimately cause more land ice to melt. The exchange ends with an awkward silence over the length of ice ages, and Stockman eventually getting interrupted by the committee’s sitting chair to move on with the hearing.