It is popular to gage progress towards greenhouse gas emissions reductions by how much they have been reduced since 1990. This is done by the federal government, and it is done by the Commonwealth of Massachusetts. It is the wrong measure.

The right measure is how much is left until we achieve zero emissions. That’s an easy target to know. It may not be a popular target, since it demonstrates that progress is not as remarkable as it otherwise seems. But zero emissions, worldwide, is what is necessary. And if zero emissions is truly difficult or even impossible, then adding additional capacity for carbon sequestration, pound-for-pound, per pound of carbon dioxide we deem has to be emitted is essential.

This is a difficult world to think about. It will take time to think like that. But is it well nigh time we started to think that way.