An image from the Japanese himawari satellite.
An image from the Japanese himawari satellite.

ScienceJanuary 3, 2020

Red sky at night: when the Australian bushfires crossed the Tasman Sea

An image from the Japanese himawari satellite.
An image from the Japanese himawari satellite.

Leading physicist Richard Easther explains what’s been going on with the smoky orange skies above New Zealand.

On New Year’s Day, social media in New Zealand was flooded with images of eerie orange skies above the South Island as the smoke from a continent-scale fire disaster crossed the Tasman Sea.

The smoke shows equally well in the view from space. To set the scale, it is 2000km or three hours’ flying from New Zealand to the Australian coast; roughly, London to Moscow, or Denver to Washington DC.

The above stunning image (and you’ll be seeing more of them as the fires burn) was taken by the Japanese Himawari satellite. The spacecraft is in a geostationary orbit above the Pacific, keeping track with the rotating Earth and high enough to take images of the whole hemisphere beneath it.

There is no sensible doubt that the magnitude of this crisis is driven by climate change. Australia has always had fires, but climate change makes the continent hotter and drier, nudging more places above the tipping point on which fire will take hold, on more days of the year.

Climate change is, ultimately, an unintended consequence of human ingenuity. We can summon light at the flick of a switch, cross continents in a day, and the world’s knowledge is at our fingertips. Billions of humans have access to miracles that emperors could never command.

In fairy tales and fables, wishes granted by genies always come with an unanticipated price. These real-life wonders are no exception: carbon dioxide is poured into the atmosphere as we forge steel, burn fossil fuels to power cars and planes and generate electricity.

When Pandora’s Box was opened, while all manner of harm was unleashed into the world the last thing to be found in the box was hope. Climate change is not a myth or a fairy tale, but hope is still to be found in the satellite images of smoke spilling across the Tasman. Our capacity to snap pictures from space is just one the tools we have to understand the climate and underscores our ability to develop technologies that let us walk more lightly on the earth. Ironically, our ability to significantly, albeit unintentionally, change the planet within a few generations reminds us that we have shaped the world that we live in, and can do so for both worse and for better.

If you’ve been reassuring friends and family and yourself that climate change is probably nothing to worry about, look at the news from Australia. Take a moment. Take a deep breath. And think again.

There are people who’ll try to minimise and muddy the role of climate change, by telling you that this is all a mistake, or a con; that the fires were lit by arsonists; that forest floors should have been cleared of fuel. But none of this explains the ferocity of the scenes we are seeing on our screens and hearing from friends across the Tasman.

There’s no shame in having gotten it wrong when people have profited from telling you not to worry, glib climate sceptics get air time and media sites earn clicks from spreading ignorance as well as elucidation.

In truth, the science is complex. Weather forecasts are in Celsius (or Fahrenheit, for Americans) but the universe thinks in Kelvins; degrees above absolute zero. Average temperatures have moved 1 degree Celsius, or 1 Kelvin. A 25 Celsius day is 298 Kelvins, so the global change in temperature we’ve seen so far is just over 1 part in 300. At the scale of the universe, our current planetary warming is small change.

But ecosystems are finely balanced, and attuned to differences in temperatures, not its absolute value – like passengers in a small boat getting seasick from a gentle swell on top of a deep ocean. For Australia, an extra degree or two means hotter days, less rain, more heatwaves, more fires, which burn more fiercely once they get started. If our carbon emissions do not shift radically from “business as usual” that is only going to get worse.

The real challenge is not scientific: it is social and political. We know what we need to do, and we can figure out how to do it. But we need to make it happen. If you are looking for New Year’s resolutions, try some of these. Drive petrol-powered cars less. Ride a bike more (you’ll get fitter). Get solar panels (which will likely save you money). Think carefully about the food you eat and how it’s grown. Purchase thoughtfully. Fly less. And this is the big one: insist that our leaders are serious about climate, and expect them to follow through on their promises.

You should worry. You should not despair.

I’ll close on this. Another New Year’s Day photo from New Zealand, a South Islander whose security lights flicked on at noon, as smoke darkened the skies. I’m a scientist and a rationalist; I don’t believe in fairy tales or fables. But you could take this as a sign.

First published at Excursionset

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