Global surface temperatures are up 0.9 degree Celsius since 1970. Who could have seen that coming?
Well, climate scientists, for one.
In the first review of its kind, researchers have shown that climate models used since 1970 to predict the rise in global temperatures as a result of greenhouse gas emissions have been largely accurate. Scientists knew then exactly how the emissions would affect the world around us.
More important, they know exactly how it will affect us in the future. We must listen.
The study found 17 forecasts from 14 separate models used between 1970 and 2001. Ten of the 17 forecasts nailed the change in surface temperature through 2017 – the latest date with available information – while the seven older models missed by as much as 0.1 degree Celsius per decade.
But those older models were only wrong because they overestimated the amount of emissions, a human factor that is tough to get right over decades. Once the models were changed to reflect the difference in emissions, they too got the temperature right.
An entire branch of climate-change denial was built on delegitimizing scientists who have been saying for decades that greenhouse-gas emissions from human activity were raising temperatures in a direct and measurable way, and that because of that knowledge we could predict how much temperatures would go up – and what those increases would mean for life on the planet.
We can’t go back and change that now, but this study is one more reason to throw such denials out the window.
More than that, though, it’s another reason to listen to the science when it tells us what’s going to happen in the next 50 years if we don’t cut greenhouse-gas emissions, particularly those from carbon dioxide, steeply and soon. The climate models have only gotten better in recent years, and the study shows that the early ones – the rudimentary models computed using punch cards – were still pretty spot on.
Then it’s up to us what to do with it.
Unfortunately, worldwide emissions have continued to rise since the signing of the Paris climate accords in 2016. Most countries are not on target to meet emission goals laid out in the agreement.
The Trump administration has abdicated world leadership on the issue, having announced the U.S. will pull out of the Paris agreement next year. The president and the Republican-led U.S. Senate have blocked and dismantled the federal response to climate change.
Maine, however, has shown what can happen when people who take the crisis seriously are put in a position to do something about it. Gov. Mills has set the right goals for reducing fossil fuel use and carbon emissions, and along with the Democratic-led Legislature last session passed laws in that direction.
If Washington doesn’t act likewise, we know just what the future will look like.
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