In 2009, a study led by NOAA and published in the Proceedings of the National Academy of Sciences (PNAS) carried a sobering title:
Irreversible climate change due to carbon dioxide emissions
The media pounced with equally sobering headlines, like this one from NPR:
Global Warming is Irreversible, Study Says
Since then, there have been similar (sometimes modified) pronouncements. As the Guardianreported in 2011, the International Energy Agency (IEA) warned that the world was on the cusp of irreversible climate change. Last year, a different batch of scientists said the same thing. This repeated warning about "irreversible climate change" is usually accompanied with a last chance pitch, as in: Act Now or Climate Catastrophe is Assured. But convincing the world to hurry up and get off fossil fuels is not as easy as selling the "smart mop" or "buns of steel" on late night informercials. Some scientists have also become concerned that people may be misunderstanding this whole "irreversible climate change" thing. So the lead author of that 2009 PNAS study (the one with "irreversible" in the title) recently co-authored a piece in Science called, "Irreversible Does not Mean Unavoidable." If that only confuses you more, go to Skeptical Science (or Climate Central) for the distinction between "irreversible" and "stoppable." The short version is that a certain amount of warming is already here but the rate of warming can be arrested if we stop putting greenhouse gases in the atmosphere. Nobody realistically expects that to happen anytime soon, though, so we know the planet is going to continue to warm. We just don't know how much and what the full effects are going to be down the road. While I'm no alarmist, as the parent of two young children I'm not exactly sanguine about the trajectory the world is on. But wait--hold the presses!--a new study gives us hope, according to the Guardian:
Dangerous global warming could be reversed, say scientists.
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