Carbon accounting tricks won’t be enough to solve the climate crisis, and “disaster looms if big finance is allowed to game the carbon offsetting markets to achieve ‘net zero’ emissions,” global change scientist Simon Lewis argued last week in an opinion piece for The Guardian.

“An astonishing global shift is under way: 127 countries have now stated that by mid-century their overall emissions of carbon dioxide will be zero,” and “companies are enthusiastically signing up to similar ‘net zero’ goals,” Lewis writes. “Finally, the international community seems to have accepted the scientific fact that we need to stop adding greenhouse gases to the atmosphere to stabilize our climate.”

But “big problems remain,” he warns. “Long-term commitments have not resulted in sufficient near-term actions,” with a United Nations assessment late last month concluding that countries’ revised carbon reduction targets to date will only reduce emissions 0.5% from 2005 levels by 2030.

That report prompted UN Secretary-General António Guterres to declare “a red alert for our planet,” adding that “decision-makers must walk the talk. Long-term commitments must be matched by immediate actions to launch the decade of transformation that people and planet so desperately need.”

But while new national climate commitments, or Nationally Determined Contributions (NDCs), roll out ahead of this year’s UN climate conference in Glasgow, “a more insidious problem is emerging,” Lewis writes. “Net-zero increasingly involves highly questionable carbon accounting. As a result, the new politics swirling around net-zero targets is rapidly becoming a confusing and dangerous mix of pragmatism, self-delusion, and weapons-grade greenwash.”

Lewis explains that net-zero calculations with a 2050 target date depend on some degree of atmospheric carbon removal, from low-tech methods like forest restoration to high-tech approaches like carbon capture and storage. “In theory, this is all fine, as pragmatically some carbon removal is needed to balance hard-to-reduce emissions,” he says.

“But negative emissions and offsetting alone are not a route to net-zero,” he adds, and “by believing in the promise of these methods, we are too often deceiving ourselves, in three major ways”: by over-relying on carbon removal to preserve a fossil-fuelled status quo; offsetting against future emissions trajectories rather than removing actual emissions from the atmosphere; and “not getting what you think you’re paying for in the self-regulated global carbon market.”

You’ll want to read Lewis’ argument in full detail, but his bottom line is crystal clear. “Urgent discussion is needed about what comprises a ‘residual emission’ that requires offsetting,” he writes. “It is the only way to contain the bad actors and release the capital of good actors.” That means “solving these carbon deceptions should be a core outcome of the Glasgow COP 26 climate summit.”

Otherwise, “new carbon-based financial products could boom, with little impact on emissions. Just like the sub-prime crisis, few will understand what they bought, and another globe-spanning crash could sweep the world, compounding economic and climate crises causing mass suffering, as we realize again that the Earth owes us nothing. Nature doesn’t do bailouts.”