What Happens If… We Actually Exceed 1.5°C In Global Warming?

An ever-pressing question as we grapple with the current heatwave.
Scientists have warned against letting our global temperatures increase by 1.5°C compared to the pre-industrial age – but what happens if it actually happens?
sorbetto via Getty Images
Scientists have warned against letting our global temperatures increase by 1.5°C compared to the pre-industrial age – but what happens if it actually happens?

What happens if, despite our best attempts to avoid it, global temperatures actually do increase by 1.5°C?

That’s compared to the average temperatures our planet enjoyed in the pre-industrial era – which was a long time ago for humans, but in terms of the world, it was a blink of the eye.

Our activity and dependency on a carbon-spewing way of life means Earth has been hotting up at a ridiculous rate since then, as emissions heat up the atmosphere.

The 2015 Paris climate agreement saw countries vow to try and stop temperatures exceeding the 1.5°C mark, but a big question mark hangs over whether we can actually achieve that.

The highest average so far is around 1.28°C above pre-industrial levels – so we’re not exactly far off.

And scientists from the World Meteorological Organisation warned only in May that the world is almost certainly likely to experience temperatures higher than the 1.5°C rise by 2027 – even if for a brief period of time, with the climate crisis exacerbated by various weather systems.

The United Nations (UN) said this change will put the world in “uncharted territory” and is likely to become an increasingly frequent phenomenon.

The World Meteorological Organisation believes if we end up exceeding 1.5°C regularly, there will be above average rainfall in northern Europe, Alaska, northern Siberia and the Sahel in Africa.

They suggested temperatures between 2023 and 2027 are likely to swing between 1.1°C and 1.8°C above pre-industrial average, too. Heatwaves will therefore worsen, exposing an estimated 14% of the world population to extreme heat once every five years.

Oceans will also warm up (although they are already starting to), which seriously damages coral – sometimes to the point of no-return.

Inside Climate News claims that up to 90% of all reefs could die out, while 7% of the Earth’s land area will transform into drier landscapes – so grasslands become deserts.

The outlet also explained that storms are likely to increase, because a hotter atmosphere means it’s wetter. Warmer air can carry more water, resulting in more intense weather conditions which could batter infrastructure around the world.

The huge swathes of ice sitting in Greenland and Antartica will probably melt. It’s already declining at an astonishing rate, but an extra 580,000 to 1 million square miles of permafrost could thaw if we go past 1.5°C to 2°C.

At 1.5°C the Arctic would be ice-free once a century. At 2°C, it would be once every decade.

In turn, that means sea levels could rise by between one to three feet by 2100, according to the UN’s research group, the Intergovernmental Panel on Climate Change (IPCC). People would be at risk along coastlines, where storm surges are more likely, while some islands could end up under water altogether.

According to Inside Climate News, this could equate to between 10 to 30 inches, putting 10 million more people at risk.

The outlet also warned that there would be mass displacement of people, and probable conflicts.

Warming could disrupt ocean circulations, too, so western Europe could become far less temperate and a lot cooler, more like Scandinavia.

Crucially, though, these changes don’t just happen the moment we reach the 1.5°C threshold. They are incremental.

As Penn State University climate scientist Michael Mann told Inside Climate News in 2018: “A better analogy is a minefield. The further out onto that minefield we go, the more explosions we are likely to set off.”

Before You Go

Go To Homepage