On Climate, Forget 2 Degrees. Let’s Talk Net Zero

By emphasizing temperature goals, it's relatively easy for nations to appear to be doing more to address climate change than they really are, and harder for the public to discern the shortfall.

This piece was first published on Forbes on September 30, 2018. It is reprinted with their permission.

In September California Governor Jerry Brown dared to take the climate change conversation where it really needs to go, call it a “let’s talk turkey” moment, when he issued an executive order that would push the state to net zero carbon emissions by the middle of this century. The order, though not binding, is striking in that it bypasses talk of the symptoms that seem to define public discussion of climate change, notably rising temperatures, crumbling Antarctic ice shelves, and extreme weather of both the dry and wet varieties.

Instead, Brown’s order directly addresses the malignancy at the root of the global climate illness, carbon dioxide emissions and the broader class of greenhouse gasses that includes methane and HFCs.

The semantic distinction is important, because words can provide cover for inaction or, more generously, a lack of action sufficient to address the immediacy with which humanity must accomplish the single, monumental task of stopping more CO2, on net, from entering the atmosphere.

Nowhere is this cover more apparent than in the Paris Climate Accord, mankind’s most ambitious, unified effort to date to address global warming (regardless of U.S. participation). The Paris agreement’s primary stated aim is to limit climate warming to 2 degrees Celsius, and 1.5 degrees if we have the most amazing luck. This threshold is based upon scientific consensus that any greater increase will bring the worst that climate change has to offer.  

To keep below the temperature threshold, and do so as cheaply as possible, governments will need to act aggressively and in a coordinated manner to stop global net emissions growth right now, or more precisely by 2020. Of course, we’re nowhere near accomplishing this goal, as global carbon emissions are in fact very much on the rise.

And here is where the focus on temperature targets is of great disservice to our climate.  

By emphasizing temperature goals, it’s relatively easy for nations to appear to be doing more to address climate change than they really are, and harder for the public to discern the shortfall. The signatories to the Paris agreement (essentially the entire world), by setting the 2 degree temperature limitation as the pact’s marquee ambition, obscure the fact that concrete carbon emissions reductions are, in fact, the real goal.  This is why it is possible, today, for nations to support a 2-degree agreement yet, despite Paris, remain track for a 3.5 degree rise in average temperature.  Paris does set net zero emissions as a goal, but a far off and vaguely timed one to be reached somewhere between 2050 and 2100.

Oliver Geden, a lead author of the next major global climate analysis from the Intergovernmental Panel on Climate Change, the 6th Assessment Report due in 2022, recently summed up one aspect of the resulting dilemma.

“If you have a temperature target then a country can say, well, I really support that temperature target and I’m doing everything I can, but others will have to do more,” Geden says.

Alternatively, numeric carbon targets are straight forward, and would make it easy for countries to get right down to the job of divvying up the global budget and communicating that budget internationally and to their own citizens. The clear, numeric goal would provide an undeniable benchmark for entire economies to align toward achieving the goal. There would no longer be ambiguity around the extent to which nations, and the globe, are on track.

Of course, this would make it more difficult for politicians to publicly accommodate constituencies with varying priorities when it comes to climate. Which makes Brown’s order, as the leader of the world’s 5thlargest economy, all the more noteworthy. True, the fact that Brown is headed for retirement means that the stark political and economic realities of net zero emissions will be dealt with by his successors. Yet, the reality that Brown’s order comes as he prepares to depart focuses attention on the fact that net zero is the goal that really matters. It just takes courage, or the promise of freedom from public life, to say so, even for someone who has worked as hard on emissions as Brown.

Finally, the focus on net-zero emissions brings the broader climate effort into focus in a way that talk of temperature cannot. When talking about net zero, the reality that we’re talking about an economy-wide emissions reduction effort becomes starkly clear.

A discussion of true net-zero encompasses industry, air travel, and 4.5 billion flatulent cows, pigs and sheep around the world and, quite possibly, our hunger for them. It focuses discussion on forests and offsets while, at the same time, we realize that our preoccupation with electricity sector emissions and car fuel economy is but part of a much broader effort. And, as Brown’s order goes beyond carbon net zero to contemplate mandatory negative emissions, we must seriously contemplate the promise, or falsehood, that holy grails like carbon capture and sequestration, and cooling schemes like solar geoengineering, will make everything all right.  

Net zero is an overwhelming conversation. Which is why it’s the conversation that needs to be had.

Andy Stone

Energy Policy Now Host and Producer
Andy Stone is producer and host of Energy Policy Now, the Kleinman Center’s podcast series. He previously worked in business planning with PJM Interconnection and was a senior energy reporter at Forbes Magazine.