Two Years to 1.7°C: the “Prediction Game” We Can’t Afford to Lose

Australia’s sweltering through another early-summer heatwave, and I’m trying to decide whether to write about the weather outside my window - or the bigger climate system we’re reengineering on this planet.

I’ve chooses the bigger one.

This week, Professor James Hansen and colleagues published projections that the global temperature record could reach +1.7°C by 2027.  That’s not a throwaway line from a pundit. It is a blunt forecast from one of the world’s most influential climate scientists - the former Director of NASA’s Goddard Institute for Space Studies.

And if that number lands in your gut the way it landed in mine, good. It should.

Hansen expects the 12-month running average global temperature to dip for a few months - down toward about +1.4°C - before rising again as El Niño kicks back in during 2026. This will set up a potential new record in 2027.

So what’s the “so what”?

The “so what” is that our climate system is now at the edge of thresholds we once talked about as “mid-century” problems. And the warming is accelerating - not merely continuing.

Even if you treat the +1.7°C as a forecast with uncertainty (as all forecasts are), it’s the direction and the time horizon that matter. Two years is nothing in climate time. It’s less than a federal election cycle. It’s the span between Year 10 and Year 12 for a student who will live through what we’re locking in now.

A crucial note about baselines (because people will weaponise confusion)

Hansen’s figures are expressed relative to 1880–1920.  The Paris and IPCC framing of 1.5°C and 2°C warming is typically relative to 1850–1900.  Those aren’t identical baselines, and the difference isn’t just academic - people will use it to dismiss, downplay, or “gotcha” this whole warning. The honest way to say it is: Hansen’s +1.7°C isn’t automatically the same as “Paris +1.7°C.” But it’s still a massive flashing red light, because it describes a near-term world with global temperatures pressing into territory where impacts escalate sharply.

Why I’m taking this seriously

Hansen isn’t playing a parlour game. He explicitly says he’s playing a “prediction” game to test understanding and accelerate scientific progress. That matters, because the default mode of public climate discussion is still: understate, hedge, soften, reassure, defer.

But in the real world - outside seminar and Ministerial meeting rooms - every fraction of a degree is lived experience: heat that drags on the body, fire weather that sharpens, floods that arrive with less warning and more violence, reefs that bleach again before recovering from the last bleaching, and ecosystems and species that run out of “adaptive capacity” long before the modelling graphs look scary enough.

If we are flirting with +1.7°C in the next two years, it means the “window” we keep talking about is not a metaphorical one. It is an actual closing aperture, with real consequences.

The political temptation: shrug and move on

Here’s what worries me more than the number itself: the way the world is learning to ignore or absorb these numbers without action.

We’ve become skilled at living with cognitive dissonance:

• That “record year” is becoming an annual headline.

• That “unprecedented” is now a familiar adjective.

• That “once-in-a-century” events are being rebranded as the new normal.

The human mind adapts to almost anything. That is a gift but also a curse. The climate system doesn’t negotiate with our coping mechanisms.

So we need to treat the next two years as a mobilisation window, not a period to wait for better news. Whether we hit +1.7°C on one dataset or another is less important than whether we keep adding to what’s driving the trend.

It’s time to hold our leaders to the speed of physics. If the climate can shift meaningfully in two years, then “net zero by 2050” without strong near-term cuts isn’t a plan - it’s just a slogan. And slogans don’t cool the planet!

I don’t know whether we will see +1.7°C in 2027 exactly as Hansen projects. But I do know what it means that such a projection is plausible enough to publish, sign, and stand behind.

In a sane political culture, this would be treated like an emergency briefing. Instead, it will compete with culture wars, cricket scores and Christmas shopping. That’s the real scandal.