A planet called Earth.

It will be one of the most important scientific papers ever, and for NZ it’s huge

Monday sees the release of a new IPCC report that will tell us whether keeping warming under 1.5deg is possible. The next question will be: do we have the will, writes Adelia Hallett

One of the most important scientific papers ever produced will be released on Monday, and the ramifications for New Zealand could be huge.

Not that you would know it from its name. Global Warming of 1.5deg, an IPCC special report on the impacts of global warming of 1.5deg above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty hardly rolls off the tongue, and the shorter title, SR15, doesn’t tell you much.

But what the report will tell us is whether it is possible to keep global warming to no more than 1.5deg, and whether we are on target to do it.

The answer to the second question is easy: no. The world is already more than 1deg warmer than it was at the start of the Industrial Revolution (New Zealand’s temperatures have increased by 1deg since records began in 1909), and at the current rate of emissions, is likely to be about 4.5deg above pre-Industrial levels by the end of the century.

Even if all countries honour their Paris Agreement emissions reduction targets (known as Nationally Determined Contributions), the world is still likely to be 3.2deg hotter by 2100.

That is unacceptable. Literally. A world that is 3.2deg hotter than it has been for the past 12,000 years is one that humans have never experienced, and one that we don’t know that we can even survive in. We certainly won’t be flourishing.

Even 2deg of warming – the Kyoto Agreement target that is still the number most talked about in public – means massive changes to our way of life. Not just keeping warming to 2deg (although that does require big changes) but actually living in a world with that level of heating.

An increase in average temperatures of 1deg above where we are now doesn’t sound like much, but the impacts are cumulative. Storms are exponentially bigger. Droughts are more intense. Sea-level rise is higher and floods more extensive. Twice as many species are imperilled at 2deg of warming than at 1.5deg of warmer.

Recently, scientists warned that 2deg of warming could trigger tipping points (things like melting permafrost and changes to ocean circulation and weather patterns) that send the world into a state known as Hothouse Earth.

This is not fanciful; the planet has been there before, albeit at a time long before humans evolved. And it’s not pleasant, at least not for a species like ours.

At 1.5deg of warming, the scientists said, it was possible that we could avoid the worst impacts of warming. Not continue with life as it is now, but find a sort of equilibrium in which we have to live with the consequences of some warming without heading into full-blown catastrophe.

Are they right? Undoubtedly, at least in principle. The Earth is an integrated system; play with one bit and you affect it all. We’re changing the concentration of atmospheric greenhouse gases, and the entire system is changing in response.

The exact tipping point for Hothouse Earth is unknown, but if reputable scientists who have spent their lives studying this stuff are telling us it could happen at less than 2deg of warming, we’d be wise to listen and do everything we can to stay well short of that point.

What does this mean for New Zealand, with our 0.17 per cent of global emissions? It means that what we are doing isn’t enough. It means what we propose doing (carbon-neutral by 2050) is unlikely to be enough.

And it certainly means that the current government’s softly-softly-don’t-scare-the-horses approach isn’t enough.

Collectively, small nations like New Zealand are responsible for nearly a third of the world’s emissions and therefore cannot be ignored. New Zealanders also have one of the higher per capita rates of emissions in the world, so we don’t get a free pass that way either.

A leaked draft of the IPCC’s 1.5deg report said that the world is likely to be have used up the carbon budget for 1.5deg of warming by 2040.

And last week, one of the report’s lead authors, Professor Drew Shindell, said that the only way we are going to stay within the 1.5deg limit is through a massive and immediate transformation in the way we generate energy, use transportation and grow food.

“It’s extraordinarily challenging to get to the 1.5deg target and we are nowhere near on track to doing that,” he told the Guardian.

“While it’s technically possible, it’s extremely improbable, absent a real sea- change in the way we evaluate risk. We are nowhere near that.”

New Zealand is doing reasonably well on some aspects of electricity generation, but generates massive amounts of greenhouse gas emissions from agriculture, and our transport emissions are rising every year.

The key point likely come out of the IPCC report on Monday is that keeping warming to 1.5deg is possible. All we need is the will. How we respond is up to us. We choose whether we dig deep and do what has to be done, or collapse in a heap, arguing about whose responsibility it is and whether it really is a problem anyway.

The latter is not usually our way; being afraid of something that is hard didn’t get New Zealanders to the top of Everest or stop us giving the vote to women, taking on apartheid in South Africa or nuclear testing in the Pacific.

The ground on climate change has shifted; almost everyone now agrees that cutting emissions is a matter of when, not if. But the 30 years we have wasted in science and policy battles are now coming home to roost. We no longer have the option of an easy transition to a low-carbon economy.

On Monday, the scientists of the IPCC are likely to tell us that if we want to keep warming to no more than 1.5deg (and we should), then we have little more than a decade to make huge emissions cut.

How we respond to that message will, literally, determine our fate.

Adelia Hallett is the publisher of Carbon News and Forest & Bird’s climate advocate


The Spinoff’s science content is made possible thanks to the support of The MacDiarmid Institute for Advanced Materials and Nanotechnology, a national institute devoted to scientific research.

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