In The Guardian, the headline was “Ambitious 1.5C Paris climate target is still possible, new analysis shows.” But over at Breitbart, readers were told that “Climate Alarmists Finally Admit ‘We Were Wrong About Global Warming.’” Other headlines spanned pretty much the entire range between these two. The grist for the mill was a new study published in Nature Geoscience by a group of well-known climate scientists, but different news outlets baked very different breads with it.
That happens pretty frequently these days, but, in this case, the new study was especially complex and more easily misunderstood—even by those without a Breitbartian aggressive ideological bias against climate science.
The story in Nature Geoscience starts with a widely used figure from the latest report from the Intergovernmental Panel on Climate Change. The figure was meant to provide an easier way to represent the consequences of future greenhouse gas emissions. It turns out that the relationship between global warming and the total amount of greenhouse gas emissions since the Industrial Revolution is roughly a straight line (at least for the near future). So rather than trying to match accounting of greenhouse gas emissions with one of myriad scenarios of future gas concentrations, you have a much simpler way to describe our situation: to limit warming to less than x degrees, you can emit no more than y CO2. This is the so-called “carbon budget.”