What chance of zero carbon emissions by 2050?

The net zero concept is simple – and applies to everyone, but could countries really achieve it by mid century?

(Pic: Bigstock)

(Pic: Bigstock)

By Jonathan Grant

The ‘Elements for a draft negotiating text’ was published at 06.30 this morning to mark the start of the second week of the negotiations.

This is the first draft of what could ultimately become the Paris Accord. It covers mitigation, finance, adaptation, capacity building, technology transfer, timeframes and institutional arrangements.

For each theme there are different options – seven different options in the case of the length of the commitment period. But, after the preamble, the first big topic in the negotiating text is mitigation.

One of the paragraphs refers to full decarbonisation by 2050.

There is a clear rationale for a long term, net zero emissions sustainable development pathway. Climate change is a ‘stock’ problem, but most of the targets proposed to address it, refer to slowing the ‘flow’.

By definition, to keep within the finite 2 degrees budget, all countries will eventually have to be at net zero emissions (i.e. after accounting for carbon uptake from forests or bioenergy +CCS).


The net zero approach also has the benefit of being much easier to communicate. Current targets refer to different reductions compared against different baselines or different business as usual growth scenarios.

Net zero is simple – and it applies to everyone.

PwC’s Low Carbon Economy Index draws a pathway to zero emissions from the energy sector by 2100.

Depending on the country, we assume slow to moderate long term economic growth.

We calculate that on average countries would need to decarbonise their economies at 6.2% every year to stay within the 2 degree carbon budget.

Roughly speaking, 6.2% should be the difference between your economic growth and your emissions reductions, so, if your economy is growing at 2% each year, your emissions need to fall by about 4% per year.

It is exceptionally rare that countries achieve this level of decarbonisation.

The US achieved it for one year during the peak of its shale gas revolution. But no country has ever rapidly decarbonised its economy over a period of years or decades.

Even when the French made a dramatic shift to nuclear power in the 1980s, they only achieved an average annual 4% reduction in emissions over that decade.

Paris outcome

In other words achieving zero emissions by 2050 would require revolutions in every sector of every country over decades.

This includes the steel, cement and chemicals sectors, which look more challenging than electricity decarbonisation. Although governments still talk about 2 degrees, there is a huge gap between ambition and reality.

And while many politicians warn of the dangers of climate change, they are not being clear with voters about the scale of change needed to address it.

Negotiators here in Lima will no doubt add to the text this week rather than refine and reduce it. Over the coming year, they will decide whether to include the net zero target.

Some recognise that the emissions targets pledged in 2015 are unlikely to add up to 2 degrees. Already, some delegations are asking ‘what’s the narrative coming out of Paris going to be?’.

They may well get a deal there, but what are the chances that it will be a 2 degree deal?

Jonathan Grant is a director in PwC UK’s climate change team. Follow him during the Lima talks on twitter @JG_climate

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