That it is difficult to build an effective carbon offset strategy is not news. But this demonstrates the extent to which such a misguided strategy can go awry.
A policy brief at the University of California - Berkeley estimates that landowners may have overstated their emissions reductions by 80 million tonnes, a third of the total cuts that California will make in the next ten years. There are primarily two reasons for the causes of this misstatement: leakage, in which a landowner reduces emissions only by retaining trees in the part of the land that is being used for offset purposes while increasing the felling figures in another, and additionality, in which a landowner gets paid for not harvesting a piece of land even if they had no intentions of doing so in the first place.
It will be interesting to see the implications that this brief has on California's ambitious emissions target reduction program. The state is committed to reducing greenhouse gas emissions by 40% below its 1990 levels by 2030. Transitioning to renewable energy sources for electricity is a key tactic to achieve that goal. Will these figures nudge a revision to target figures in that direction? Or, will the state adopt the carbon tax route? My bet is on the latter.