Calling time on 1.5C doesn't mean giving up

Analysis: Three grim reports last week charted the world’s failure to reduce greenhouse pollution and the increasingly unlikely path to limiting global warming to 1.5C.

On Thursday, the United Nations climate body evaluated the latest emissions pledges made by 193 signatories of the Paris Agreement and found they fell collectively short of the pact’s goal of “holding the increase in the global average temperature to well below 2C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5C above pre-industrial levels”.

Even if all countries meet their most ambitious Paris pledges, the report said, emissions in 2030 will be no lower than they were in 2019. That’s still down 9.5 percent from the 2030 levels predicted on the basis of previous Paris commitments, but nowhere near the 43 percent reduction on 2019 levels the latest science says is needed to meet the 1.5C goal.

For the first time, these projections show emissions won’t still be rising after 2030. But they won’t be in the headlong fall necessary this decade.

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This was followed by a double whammy of reports on Friday morning (NZT).

First, the International Energy Agency’s annual energy outlook report offered a similarly optimistic-but-clearly-not-enough prediction for the future: Global fossil fuel use will peak this decade but not fall nearly as steeply or quickly as needed to limit warming to 1.5C.

Coal may bounce back briefly in response to Russian gas embargoes, but it will be in “structural decline” from the middle of the decade. There won’t be a new golden age of fossil gas either – while last year’s report estimated a 20 percent increase in gas use by 2050, this year’s says we’ll burn the same amount in three decades as we do now.

Projections for the deployment of renewable electricity generation were revised upwards, with solar up a whopping 21 percent.

And yet, as with Paris pledges, this progress isn’t close to what’s needed. The energy pathway to 1.5C is “narrow but achievable”, the international energy body reported. At the same time, however, it has already had to tweak its net zero scenarios, which were first debuted last year, to account for 12 more months of delayed action.

It’s just the latest example of what CarbonBrief journalist Simon Evans calls “the ski slope of missed opportunity”.

The precipitousness of that slope was further emphasised by the third and final report of last week. The UN’s environment programme released its annual Emissions Gap report, on the yawning gulf between a pathway consistent with limiting warming to 1.5C or even 2C and our current pledges – and the second rift between our pledges and our policies.

Even the report’s title – The Closing Window – conveys that we are rapidly running out of time.

Under current policies, we have a 50-50 chance of keeping warming to 2.6C this century. The most ambitious Paris pledges put us on track for 2.2C of warming. If we add onto that the long-term net zero targets that don’t appear in Paris commitments, we have an even shot at 1.7C.

This is better than the 3-4C of warming we were once headed for, but it’s woefully insufficient if we’re still striving for 1.5C.

Are we still striving for 1.5C?

The Guardian‘s front page, in the wake of the emissions gap report, suggested the window has already closed. “NO WAY BACK?” it asked, while saying the UN “finds there is ‘no credible way’ to keep to the 1.5C climate target”.

That’s not exactly what the emissions gap study said. It said that countries have so far not put forward any credible policy path to 1.5C – not that there is none.

Climate science has given us a solid understanding of the emissions cuts that would be needed if we wanted a decent chance (say 66 percent) of limiting warming to 1.5C. The surge in green tech over the past few decades means we also have the technical means to make those cuts.

It is strictly feasible. Is it realistic?

The latest IPCC report, from April, said in all of the scenarios spat out by dozens of climate-economic models, the only ones which kept warming to 1.5C were those where emissions peaked well before 2025. Global emissions must effectively peak immediately (or have already peaked) to limit warming to 1.5 degrees.

Instead, with the exception of the 2020 Covid-19 blip, they are still rising. They won’t peak until 2030 under current policies.

Every tonne of emissions abated, every fraction of a degree of warming avoided, saves lives.

And that’s only the first step. After that, global emissions must enter a steep and sustained fall – down 43 percent from 2019 levels by 2030 and then 85 percent by 2050.

Last year saw yet another record set for carbon dioxide emissions, one more than 200 years in the making. We have burned ever increasing amounts of fossil fuels to develop our societies and improve out living standards since the start of the industrial revolution. Large swathes of the global population are still on that journey. It has taken us centuries.

Now, in mere decades, we have to undo almost all of that. We have to mothball our fossil fuel infrastructure, walk away from our coal and oil reserves. We also have to replace it all with green energy, requiring new minerals and materials.

Is that really realistic?

As David Roberts wrote in 2020: “The level of action and coordination necessary to limit global warming to 1.5C utterly dwarfs anything that has ever happened on any other large-scale problem that humanity has ever faced. The only analogy that has ever come close to capturing what’s necessary is “wartime mobilisation,” but it requires imagining the kind of mobilisation that the US achieved for less than a decade during WWII happening in every large economy at once, and sustaining itself for the remainder of the century.”

Saying this is a tall order is a gargantuan understatement.

But we can’t yet say it is impossible. That time may well come. Under current policies, we’ll use up the remaining carbon budget for 1.5C by the end of the decade. If we meet our Paris targets, that gets pushed back into the 2030s. Either way, that would be a date when we could officially lay 1.5C to rest.

For the moment, let’s assume we aren’t going to make it. What’s next?

The 1.5C goal is an important rallying cry. But it’s also somewhat arbitrary.

Limiting warming to 1.4C is even better than 1.5C. And if we only stop temperatures at 1.7C above preindustrial levels, well, that’s still better than 2C.

In fact, every tenth of a degree makes a difference.

Climate change is non-linear.

While 2C is only a 33 percent increase on 1.5C, it will expose 160 percent more people to severe heat, reduce crop yields by 130 percent and make sea-ice-free Arctic summers 900 percent more common.

The likely eventual loss of 1.5C doesn’t mean we should give up entirely or even settle for 2C. Every tonne of emissions abated, every fraction of a degree of warming avoided, saves lives.

The global climate movement may need to find a new rallying cry, but it should come up with something better than acquiescence to a 2C future.