Two Myths: Let's Level off Emissions & Reverse Climate Change

March 19, 2013 by Ellie Johnston

Suggesting that we can reverse climate change or that it’ll be okay because we’re leveling off emissions is thinking that doesn’t reflect the real dynamics of our world. CO2 lasts in the atmosphere for lifetimes, meaning we are already locked in to some amount of climate change. If we were to just level off our emissions and leave it at that, we would still be adding far more CO2 annually to the atmosphere than we can cycle back down to Earth without contributing to climate change.

These are just two angles on some of the misaligned, but generally well-intentioned thinking that one can run across in the daily energy and climate news. Below are two recent examples, both of which pop-up in articles from people trying to find a foothold to defend the widespread exploitation of the reserves of natural gas and oil that have been opened up by hydraulic fracturing and horizontal drilling in a warming world — a tough argument to pull off.

Myth 1: We can reverse climate change. This is from New York Times Op-ed columnist Joe Nocera last Friday:

A reduction of carbon emissions from Chinese power plants would do far more to help reverse climate change than — dare I say it? — blocking the Keystone XL oil pipeline.

Nocera has been criticized by climate bloggers for many of his recent Op-ed’s that touch on energy and climate, so it is no surprise that he has already been pounced on for his remarks in this editorial. Joe Romm at ThinkProgress describes the fallacy of “reversing climate change” here:

As a NOAA-led paper explained 4 years ago, climate change is “largely irreversible for 1000 years.”

This notion that we can reverse climate change by cutting emissions is one of the most commonly held myths — and one of the most dangerous, as explained in this 2007 MIT study, “Understanding Public Complacency About Climate Change: Adults’ mental models of climate change violate conservation of matter.”

The fact is that, as RealClimate has explained, we would need “an immediate cut of around 60 to 70% globally and continued further cuts over time” merely to stabilize atmospheric concentrations of CO2 – and that would still leave us with a radiative imbalance that would lead to “an additional 0.3 to 0.8ºC warming over the 21st Century.” And that assumes no major carbon cycle feedbacks kick in, which seems highly unlikely.

We’d have to drop total global emissions to zero now and for the rest of the century just to lower concentrations enough to stop temperatures from rising. Again, even in this implausible scenario, we still aren’t talking about reversing climate change, just stopping it — or, more technically, stopping the temperature rise. The great ice sheets might well continue to disintegrate, albeit slowly.

Romm cites Climate Interactive colleague and MIT professor John Sterman’s study that showed that Joe Nocera is by no means alone in holding this myth.

Myth 2: It’ll be okay if we just stabilize emissions. This thinking appears near the end of a long article by Vince Beisner in the Pacific Standard on new developments in the fossil fuel industry:

So are we doomed to a future of ever-rising temperatures? Maybe. But maybe not. It’s not all bad news: in the developed world, greenhouse gas emissions may be on track to stabilize, thanks to growing efficiency and a shift toward cleaner fuels. In the U.S., energy-related carbon emissions have fallen from a peak in 2005, and are projected to rise only slightly over the next ten years.

True that it is good news that growth in emissions is slowing, but just stabilizing our emissions is bad news for young and future generations who would face ever-increasing temperatures because our emissions would still far exceed what the planet can handle. Sterman and Sweeney’s 2007 study details this fallacy and their studies reveal that this too is a widely held misunderstanding.

Here’s the abstract from the Sterman and Sweeney’s study that lays both these myths to rest:

Public attitudes about climate change reveal a contradiction. Surveys show most Americans believe climate change poses serious risks but also that reductions in greenhouse gas (GHG) emissions sufficient to stabilize atmospheric GHG concentrations or net radiative forcing can be deferred until there is greater evidence that climate change is harmful. US policymakers likewise argue it is prudent to wait and see whether climate change will cause substantial economic harm before undertaking policies to reduce emissions. Such wait-and-see policies erroneously presume climate change can be reversed quickly should harm become evident, underestimating substantial delays in the climate’s response to anthropogenic forcing. We report experiments with highly educated adults–graduate students at MIT–showing widespread misunderstanding of the fundamental stock and flow relationships, including mass balance principles, that lead to long response delays. GHG emissions are now about twice the rate of GHG removal from the atmosphere.

GHG concentrations will therefore continue to rise even if emissions fall, stabilizing only when emissions equal removal. In contrast, results show most subjects believe atmospheric GHG concentrations can be stabilized while emissions into the atmosphere continuously exceed the removal of GHGs from it. These beliefs-analogous to arguing a bathtub filled faster than it drains will never overflow-support wait-and-see policies but violate conservation of matter. Low public support for mitigation policies may be based more on misconceptions of climate dynamics than high discount rates or uncertainty about the risks of harmful climate change.

For a great interactive demo on this check out the climate bathtub, which illustrates these dynamics using the simple analogy of water flowing into and out of a bathtub.