For more than a decade, global surface temperatures have defied our best climate models by refusing to rise, even as we pump out unprecedented levels of greenhouse gases. A new study has a new explanation for why our models are getting it wrong: equatorial winds. Evidently, Pacific trade winds have been blowing much harder over the past 20 years than they normally do, and as a result, surface heat is being stored in our oceans. The FT reports:
These easterly winds, which blow across the tropics, have speeded up ocean circulation at the equator, pushing heat deep down into the ocean’s depths and bringing cooler water up to the surface.
This has driven more cooling in other regions and accounts for much of the reason why global average air surface temperatures have stayed virtually steady since 2001, says the paper, published in this week’s Nature Climate Change journal.
The study’s authors were careful to note that this phenomenon was anomalous, and that this halt in global warming should restart once the strong winds abate. But they also were unable to identify why the normally cyclical winds have been so strong in recent years, or when they might be expected to return to more normal levels.That kind of uncertainty isn’t surprising—the planet’s climate is an extraordinarily complex system of variables and feedback loops that we don’t fully understand. But our tenuous grasp of how and why our climate does what it does has profound effects on environmental policymaking. So much of what the green movement clamors for when it comes to crafting climate change adaptation and mitigation strategies is based on hard numbers—avoiding a specific amount of global temperature rise, keeping carbon emissions below a certain level, and so on. Unfortunately, much of the data can’t be trusted, given our current paucity of knowledge regarding—quite literally—the way the world works. How can politicians to craft effective green policies, which so often seem to require short-term sacrifices, when the hard data supposedly underpinning the outsized dangers of inaction is unreliable?They can’t. But that doesn’t mean that we shouldn’t still work toward mitigating and adapting to climate change. At the most basic level, we do know that certain gases trap the sun’s heat, and that’s a problem. Given the uncertainty over the fiddly bits, we would be much better off pursuing policies that achieve both environmental and economic ends. Stop subsidizing expensive wind and solar energy, and focus more on energy efficiency measures. Abandon the quixotic fight against the Keystone XL pipeline and promote more shale gas extraction. A smart green movement would recognize that growth and sustainability are not necessarily mutually exclusive concepts, and that strategies that wed the two are a lot more likely to work than unicorn hunts predicated on shaky data.