A study published this weekend in Nature Geoscience has double-checked, and confirmed, the idea that climate change is mostly human-made. It uses "an alternative line of evidence" to prove that most observed climate change — 74 percent of it — comes from greenhouse-gas emissions, not natural variability.
We basically knew that already, but it's always good to have independent confirmation. That’s kind of the difference between science and just saying shit on Fox News.
What's more, the study states unequivocally that a pet climate skeptic theory (not our fault! more solar energy has reached the earth!) is just wrong. The paper's abstract puts it like this:
The observed trends are extremely unlikely (<5%) to be caused by internal variability, even if current models were found to strongly underestimate it.
Or, to put numbers on it, changes in solar radiation account for, at most, a 0.07 degree C [0.126 degree F] change in global temperatures. The observed change? 0.56 degree C [1.008 degrees F], or eight times what nature can be held accountable for.
In other words, natural shifts are playing a role in the changing climate. But they're dwarfed by the changes for which humans can and should take responsibility.