Social Channels


Additional Options

Date Range

Receive a Daily or Weekly summary of the most important articles direct to your inbox, just enter your email below:

Thermal power plant and flourishing woods in foreground
11 December 2015 18:01

COP21: Experts discuss ‘greenhouse gas emissions neutrality’

Carbon Brief Staff

Multiple Authors

Paris Summit 2015COP21: Experts discuss ‘greenhouse gas emissions neutrality’

The latest draft Paris climate agreement aims to reach “greenhouse gas emissions neutrality” between 2050 and 2100.

Released in Paris shortly after 9pm on Thursday, this new language appears to have come out of nowhere, leaving journalists and analysts scrambling to understand what it means.

Carbon Brief asked a range of experts about “greenhouse gas emissions neutrality” and how it differs from the alternatives.

Long-term goal

There’s wide support for the Paris deal to include some sort of long-term goal.

Previous drafts mentioned decarbonisation, net-zero emissions or “climate neutrality”. Other options included specific percentage reduction targets for global emissions in 2050.

Carbon Brief’s explainer on the long-term goal of the deal looked at how these options differ and the various connotations they carry.

These all stem from a scientific imperative. To stabilise global temperatures, CO2 emissions have to be net-zero, with greenhouse gas emissions (GHGs) reaching zero a little later.

In June, the G7 of Germany, US, Japan and others backed complete decarbonisation this century. This is unpopular with some states because it implies an end to fossil fuels use.

Others are keen on this sort of language, precisely because it would send a clearer signal to investors that the high-carbon era is over.

Climate neutrality, once a contender for the final Paris text, has emerged as a problematic and ill-defined term that could allow geoengineering to offset continued emissions.

Meanwhile, any reference to “net-zero” emissions or “emissions neutrality” continues to be opposed by certain NGOs, as they dislike negative emissions and emissions offsets.

In policy and scientific circles, the new Paris language on “greenhouse gas emissions neutrality” seems to have been used much more rarely than the others. It still isn’t clear where it came from.

However, in a 2013 speech Jochen Flasbarth, a senior German negotiator in Paris, described a report on GHG neutrality produced by the German environment agency.

GHG neutrality is supported by the UK, a spokesperson tells Carbon Brief. China opposes it, preferring “low-carbon development”. In China’s view, this phrase encompasses carbon neutrality.

Here’s the language in the current draft text.

Extract of Article 3 of 10 December Paris text draft on long-term goal and greenhouse has neutrality.

Draft Paris climate agreement of 10 December. Credit: UNFCCC.

The text doesn’t contain any other options. It could still change, however: nothing is agreed until everything is agreed.

GHG neutrality is more specific than “climate neutral”. It only refers to GHGs, so it excludes geoengineering. But what else does it mean? We turned to the experts.

What is GHG neutrality?

Michael Jacobs, advisor to the New Climate Economy:

“Greenhouse gas neutrality is an interesting term, which has emerged in these negotiations. It seems to me to have a pretty clear meaning. When a budget is revenue-neutral, it has the same amount of income going in as coming out. And greenhouse gas emissions neutrality is the same amount of emissions coming out as being sequestered. So it effectively means net-zero emissions.

“This comes from the IPCC, which in its 5th assessment report looked at probable 2C pathways – that is, pathways with emissions over the next decade which will stay within a reasonable probability, a 66% chance, of holding global warming to 2C – and they show that you have to get to net-zero emissions of all greenhouse gases by some time between 2080 and 2100. To do that, you have to bring carbon down a bit earlier than that, but all greenhouse gases in that kind of timescale. And that is essentially what the concept means.

“By putting it in this agreement, if it stays in, this would be a very significant signal that we have to do this according to the science. And the science says that by the end of the century, we have to reduce net emissions down to zero. And it would be a very profound statement if the international community accepted the science was telling us that’s where we need to be.”

Prof Piers Forster, climate researcher at the University of Leeds:

“My interpretation of the ‘greenhouse gas neutrality’ wording is that it more ambiguous than other options and therefore allows countries to interpret text in their own interests. It allows non CO2 gases to be considered in any accounting. It also caters to those that don’t want to go down the large scale carbon capture route via bioenergy or more geoengineering-like options, such as air capture. So both states that want negative emission technologies and those that only want conventional mitigation will be satisfied. I think it also has a timescale nuance, i.e. you can be net positive in one decade provided you promise to be negative in the next.”

Kelly Levin, senior associate at the World Resources Institute (WRI):

“After GHG emissions are reduced as close as zero as possible, any remaining GHGs could be balanced out by removals. While theoretically offsets could be used on a national level to reach national GHG neutrality, they do not play a role in achieving global GHG neutrality as collectively global emissions would need to be brought to net zero.

“To be sure, there were earlier version of the text that were clearer about the scale and rate of emissions decline needed, as well as the need to limit overall cumulative emissions. However, the GHG emissions neutrality goal is coupled with a goal to limit warming 2C or even 1.5C, and therefore it should be abundantly clear that we have to phase out emissions altogether, well before the end of the century. This means we have to end high-emitting behavior and ramp up efforts significantly if we are going to reach GHG emissions neutrality at a time that is consistent with the agreement’s temperature goal.”

You can read a longer discussion of greenhouse gas emissions neutrality from Kelly and her colleagues over at the WRI blog.

Nick Mabey, chief executive of thinktank E3G:

“While not the ideal option, we think that the compromise language on GHG neutrality will send a strong signal on the need to phase out fossil fuels. When taken with the strong language on staying well below 2C this goal implies that carbon emissions will need to reach net zero by 2050-2060. This is strong enough to make investors revise their assessments of the value of further expenditure on fossil fuel extraction projects.”

Dr Steffen Kallbekken, research director of Norwegian institute CICERO:

“The intention behind greenhouse gas neutrality is clear, but, scientifically, it’s ambiguous. It does leave a lot of loopholes. How do you treat negative emissions? How do you treat negative emissions of other gases than CO2? How do you trade off between different gases: CO2, methane, nitrous oxide, HFCs? It leaves a lot of questions unanswered. And, in the long term, what determines the temperature is CO2 and not all those other gases. And that’s something that’s left out when you no longer talk about decarbonisation or targets for CO2. I would prefer to see to clear wording on either decarbonisation or concrete cuts by a concrete year. For example, 40-70% by 2050 for the 2C target or 70-95% by 2050 for the 1.5C target.”

Prof Johan Rockstrom, executive director of the Stockholm Resilience Centre:

“We’re taking oil, coal and natural gas from the inner crust of the planet, which has been there for over a hundred million years and we’re emitting that in the atmosphere, and it stays in the atmosphere for over a thousand years. This is what is causing global warming. This must be reduced to zero, that’s what we call decarbonisation.

“Reduce the use of fossil fuel at a pace that takes us to zero by 2050. That’s the clean and very key objective to stay under 2C. But then, you see, we have ‘green’ carbon, which is the carbon that flows naturally in the ecosystems. So, you have forests taking up carbon dioxide and they release carbon dioxide. If you have oceans taking up carbon dioxide and releasing carbon dioxide.

“Now, what greenhouse gas neutrality suggests is that everything suddenly counts. So, what happens in a country, for example, that emits a lot of carbon dioxide from burning fossil fuels but has a lot of forests, can actually say, ‘Well, but our forests are taking up ten units and we’re emitting ten units, so we’re already zero. We are actually already greenhouse gas neutral because we’re counting in the sinks of carbon from our forests’.

“This is risky because we know that the only way to stay under 1.5-2C is that we actually decarbonise emissions from fossil fuels. So, that’s one side of this. It’s not necessarily an impossible term – greenhouse gas neutrality suggests reducing emissions of all greenhouse gases but it’s just that one has to recognise that we really need to go fast on fossil fuel burning.

“The other side of this is that it’s a compromise with oil nations, like Saudi Arabia, that says, well you know, we actually need to transition a bit more slowly when it comes to oil and therefore we’ll invest in carbon capture and storage, which is an engineering technology, which means that we’ll be storing carbon and therefore it can be counted as greenhouse gas neutrality because we’re emitting greenhouse gases by burning oil but at the same time we’re storing it through CCS technologies.

“So, it opens up a bit of compromise in the levels of ambition, which could have been good if we’re talking about not very ambitious targets in terms of warming. But now that we’re really in a transformative position where we need to rapidly go to zero emissions on fossil fuels by 2050-2060, it requires that we’re really serious about the terminology as well. So it is a compromise.

“Actually, I should say that Paris may actually have to accept something like greenhouse gas neutrality because we are 200 countries and Paris is the floor beyond which we actually start transforming. But, scientifically, it would have been worthwhile really staying true to – and consistent with – the science, which would be the term decarbonisation.”

Martin Kaiser, head of international climate politics at Greenpeace:

“The text talks about ‘greenhouse gas emissions neutrality’. Why can’t this conference just say it like it is, that we need to quit oil, coal and gas by 2050 at the latest? And why is there only one mention of the word renewables, and only in relation to Africa, when renewables will clearly come to dominate this century?”

Main image: Thermal power plant and flourishing woods in foreground. Credit: Rasica/
Sharelines from this story
  • #COP21: Experts discuss 'greenhouse gas emissions neutrality'
  • What is 'greenhouse gas emissions neutrality'? We asked a range of experts to tell us. #COP21

Related Articles


Expert analysis directly to your inbox.

Get a Daily or Weekly round-up of all the important articles and papers selected by Carbon Brief by email.


Expert analysis directly to your inbox.

Get a Daily or Weekly round-up of all the important articles and papers selected by Carbon Brief by email.