The Climate Contradiction That Will Sink Us – The Atlantic

Source: The Climate Contradiction That Will Sink Us – The Atlantic

The scientist James Hansen, famous for his early warnings about climate change, suggested in a paper released last week with a suite of high-level colleagues that warming is accelerating more rapidly than is presently understood: In their view, that the Earth could exceed 1.5 degrees of warming this decade is practically assured, and 2 degrees by 2050 is likely unless the world eliminates fossil-fuel use far faster than planned. These new calculations are a reflection of just how many variables go into making the livable conditions we call “the climate,” and how messing with one, even with good intentions, can have cascading effects. Part of the problem, these researchers found, was that regulations passed to reduce harmful sulfate-aerosol emissions from shipping vessels worked. Sulfate aerosols are bad for human health. But they also reflect solar radiation back into space, so less pollution also means that the Earth is absorbing that much more energy and heating up that much faster. “That’s why global warming will accelerate. That’s why global melting will accelerate,” Hansen said at a press conference.

… Kaitlin Naughten, an ocean-ice modeler for the British Antarctic Survey, co-authored a paper in the journal Nature Climate Change last month warning that the loss of much of West Antarctica’s ice sheet is now virtually inevitable. Even if future emissions are drastically curtailed, enough warming is probably locked in to wash the bulk of the sheet away. At best, she says, we are on the brink of its total loss becoming assured. The exact timing of the sheet’s total disappearance, too, is unclear. But by one estimate, the West Antarctic ice sheet contains enough water to raise sea level globally by just over five meters, or 17 feet. At the very least, Naughten told me, she thinks it would be wise to plan for two to three meters of sea-level rise, or six to ten feet, in the next couple of centuries.

…Yet in the U.S. alone, a country responsible for at least 20 percent of historical emissions, the current buildout of liquified-natural-gas infrastructure, intended to export the country’s plentiful gas, is the largest fossil-fuel expansion proposed in the world—and it’s happening under a president who recently passed the most impactful climate legislation the country has ever seen. That climate math isn’t adding up. China, which is responsible for about 12 percent of historical emissions according to Alex Wang, who studies Chinese environmental governance at UCLA, has one of the largest clean-power programs in the world. But the country is at the same time dramatically expanding its coal production.

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Oddly enough, the difference between the world we have and the one we could have is buried in two contrasting modeling reports by two of the world’s most important energy-information organizations. Whereas the International Energy Agency projected that we’d hit peak fossil-fuel use in 2030, the U.S. Energy Information Administration came to a very different conclusion: It saw demand for fossil fuels rising through at least 2050. The difference between the two agency’s models is how they treat government policy. “It’s important to understand we are modeling exactly what’s on the books as it is written,” Michelle Bowman, a senior renewables analyst at the U.S. EIA, told me. If a policy is set to expire, the U.S. EIA treats it as expiring. It doesn’t take into account policies that countries have talked about but have had yet to implement. The international agency’s analysis, in contrast, assumes countries will follow through with more climate-friendly policies and renew the ones they already have on the books. “Look how different things could be,” Bowman said. The difference is night and day, despair and hope.

Policy, and only policy, appears to make that difference. It represents the choices that our leaders make about when to finally change course.