A few weeks back in my weekly LinkedIn newsletter I mentioned the Imagine newsletter, a weekly synthesis of academic insight on solutions to climate change from “The Conversation”. It was talking about changes to the Antarctic sea ice.
“…dramatic changes are underway in Antarctica which suggest Earth's climate system is unravelling. Here in the planet's far south, sea ice surrounding the frozen continent has shrunk so rapidly that there is no precedent in nearly half a century of measurements. As ocean and air temperatures around the Antarctic rise, the region may be entering an entirely new state – with profound consequences for the rest of the world”.
For as long as satellites have been able to measure it, the ocean surface has reliably frozen at about the same pace each winter, even if the summer had seen less ice. But this year is different. "There is now an area of open ocean bigger than Greenland. If the 'missing' sea ice were a country, it’d be the tenth largest in the world." This could represent a new state for Antarctica and its ice, which takes us into unknown territory.
The lack of ice is changing the way different layers of water temperature and density influence ocean currents and ultimately our weather. For instance, the UK would have a much less temperate climate without the Gulf Stream and the North Atlantic Drift. Also, estimates suggest more than 90% of the excess heat caused by greenhouse gas emissions have historically been absorbed by the ocean. But no-one really seems to know whether this fundamental change in Antarctica means that we will see major change in our climate. Let’s be optimistic - perhaps less ice means more ocean to absorb more carbon? On the other hand…
Then we saw record temperatures again in September. The 1.5C global threshold (temperature compared to the pre-industrial average) was exceeded again, as it was in August. In fact, Copernicus, the EC climate reporting service, announced that the previous record has been smashed. The month as a whole was around 1.75°C warmer than the September average for 1850-1900, the preindustrial reference period.
“September 2023 was the warmest September on record globally, with an average surface air temperature of 16.38°C, 0.93°C above the 1991-2020 average for September and 0.5°C above the temperature of the previous warmest September, in 2020”.
The BBC also reported that around a third of the days in 2023 have seen the average global temperature at levels at least 1.5C higher than pre-industrial levels. “2023 is "on track" to be the hottest year on record, and 2024 could be hotter. "It is a sign that we're reaching levels we haven't been before," says Dr Melissa Lazenby, from the University of Sussex.
Now the IPCC (Intergovernmental Panel on Climate Change) has warned the world is on course to cross the key warming threshold of 1.5C above pre-industrial levels in the early 2030s, much earlier than previous projections. “Climate Change 2023 – Synthesis Report” was approved by 195 governments and pulls together evidence from over 100 contributors and numerous research sources. The report comes ahead of vital United Nations climate negotiations in Dubai on November 30th.
But I have a nasty feeling even this might prove to be too optimistic. 2022 saw the level at 1.26C above the threshold and as described above, the last two months have smashed through the 1.5C barrier. El Nino (the cyclical ocean phenomenon that causes higher temperatures) is forecast to have an impact next year too – so what are the odds that 2024 sees the threshold breached in terms of the average annual temperature? I certainly wouldn’t bet against it.
Even though emissions may be close to peaking globally, that still means we are putting huge amounts of carbon into the atmosphere every year. I think we need to stop talking about 1.5C and maybe even 2C targets, and explain to everyone that we just don’t know where this might stop. Even the top climate scientists have been proved too cautious in recent years in terms of their projections.
So maybe it will turn out to be 3, 4 or 5 degrees this century, and perhaps we should be honest and explain that we just don’t know. But if we see that sort of an increase, we (or our children and grandchildren) really are in trouble.