Fuzzy Accounting Around “Net Zero” Slows Progress on Climate Change

Overly optimistic accounting around the concept of net zero is hindering attempts to tackle climate change.

Net zero is the idea that any greenhouse gases emitted by humans must be balanced by an equivalent amount of carbon taken out of the atmosphere. If humans stop emitting extra carbon dioxide, methane, and other greenhouse gases into the atmosphere year over year, global warming will gradually slow as natural carbon sinks — such as oceans and forests — take up the previous excesses over decades and centuries.

But now, countries and companies are using these natural sinks in their accounting to meet net-zero goals. In some cases, this means giving themselves so much credit for their forests that they could actually increase their greenhouse gas emissions and still claim to be fighting climate change.

“We now have a situation that by maximizing our use of carbon offsets, so to speak, we could potentially pretend we are on the path to net zero by 2050 and actually do nothing at all for 15 years,” says Myles Allen, a climatologist at the Univ. of Oxford who co-authored a new report in the journal Nature calling out the problem. After 15 years, Allen notes, humanity would run out of natural sinks to claim and would find themselves facing the same need to actually remove and store carbon permanently, just under worsened climate conditions.

Allen and his co-authors were the scientists who originally laid out the ideas in 2009 that would become the basis for net-zero goals.

Two natural processes remove carbon from the...