The world is at 390 parts per million (ppm) of CO2 and 430+ CO2 equivalent. The IPCC has concluded, in what might actually be an optimistic assessment, that we can limit temperature growth to 2 degrees if we cap CO2 levels at 450 ppm. That is, limiting to 450 ppm would give us a 50% chance, in that optimistic assessments, of limiting ourselves to simply having a serious (rather than utterly fatal) crash (see graphic above).
In fact, that IPCC assessment is (again) almost certainly optimistic.
There is a growing consensus (group of understanding) that our target should not be 450 parts per million (ppm), but 350 ppm. In other words, we don’t need to just slow emissions growth and flatten overall carbon levels, but actually have as our target and objective figuring out how to move from a carbon emitting to a carbon neutral to a carbon negative future. And, we need to be doing so on all cylinders, with all approaches (energy efficiency, clean energy, changed social practices/norms, improved agricultural practices, etc …) available to us (and to the U.S.).
Right now, we are continuing to accelerate the car into the wall. Every moment that passes increases the inevitable damage and increases the risk of unsustainable damage to the planetary systems’ ability to support advance human civilization.
Graphic courtesy of Climate Place.