- Written by Georgina Ranard, Erwan Rivault, and Jana Tuchinsky
- BBC climate reporter and data team
A series of climate records about temperature, ocean temperature and sea ice in Antarctica has alarmed some scientists, who say its speed and timing are unprecedented.
The United Nations says dangerous heatwaves in Europe could break more records.
It’s difficult to immediately link these events to climate change because the weather — and the oceans — are so complex.
Studies are underway, but scientists already fear that some worst-case scenarios could unfold.
“I’m not aware of a similar period when all parts of the climate system were in an abnormal or record-breaking region,” says Thomas Smith, an environmental geographer at the London School of Economics.
Paolo Seppi, Lecturer in Climate Sciences at Imperial College London, says that “the Earth is in uncharted territory” now because of the warming from burning fossil fuels, as well as the heat generated by the first El Niño – a natural warm weather system – since 2018.
here Four climate records Breaking So Far This Summer—the hottest day on record, the warmest June on record globally, intense marine heatwaves, and record low Antarctic sea ice—and what they’re telling us.
The world experienced its hottest day ever in July, breaking the global temperature record set in 2016.
The global average temperature exceeded 17°C for the first time, reaching 17.08°C on July 6, according to the European Union’s climate monitoring service Copernicus.
Continuous emissions from burning fossil fuels such as oil, coal and gas are behind the global warming trend on the planet.
This is exactly what would have been expected in a world with more greenhouse gases, says climatologist Dr Frederick Otto, of Imperial College London.
“Humans are 100% behind the upward trend,” she says.
“If I’m surprised by anything, it’s that we see records broken in June, so earlier in the year. El Niño doesn’t really have a global impact until five or six months into the phase,” says Dr. Smith.
El Niño is the most powerful naturally occurring climate variability in the world. It brings warmer water to the surface in the tropical Pacific Ocean, and pushes warmer air into the atmosphere. It usually increases global air temperatures.
The global average temperature in June this year was 1.47°C higher than a typical June in the pre-industrial period. Humans began pumping greenhouse gases into the atmosphere when the Industrial Revolution began around 1800.
When asked if summer 2023 was what he predicted a decade ago, Dr. Smith said climate models are good at predicting long-term trends but less good at predicting the next 10 years.
“The models from the ’90s pretty much put us where we are today. But getting an idea of what the next 10 years will look like is going to be very difficult,” he says.
“Things will not calm down,” he adds.
Extreme sea heat waves
The average global ocean temperature broke records for May, June and July. It is approaching the highest sea surface temperature ever recorded, which was in 2016.
But it is the extreme heat in the North Atlantic that is of particular concern to scientists.
“We’ve never seen a marine heatwave in this part of the Atlantic. I wasn’t expecting it,” says Daniela Schmidt, professor of earth sciences at the University of Bristol.
Attributing this heat wave directly to climate change is complex, says Professor Schmidt, but that work is ongoing.
What is clear, she says, is that the world has warmed and that the oceans have absorbed most of that heat from the atmosphere.
And she adds: “Our paradigms are distinguished by their natural diversity, and there are still things that we have not imagined, or at least we have not yet imagined.”
She emphasized the impact of this heat on marine ecosystems that produce 50% of the world’s oxygen.
“People tend to think of trees and grasses dying when we talk about heat waves. The Atlantic Ocean is about 5°C warmer than it needs to be – that means organisms need 50% more food just to function as normal,” she says.
Record low in Antarctic sea ice
Alarm bells are ringing for scientists as they try to decipher the exact link with climate change.
A warming world could reduce Antarctic sea ice levels, but the current significant decline could also be due to local weather conditions or ocean currents, explains Dr Caroline Holmes of the British Antarctic Survey.
And she emphasized that it’s not just a record being broken – it’s being broken dramatically.
“This is unlike anything we’ve seen before in July. It’s 10% lower than the previous drop, which is a huge level.”
She calls it “another sign that we don’t really understand the pace of change.”
Scientists think global warming will affect Antarctic sea ice at some point, but until 2015 it bucked the global trend for other oceans, says Dr. Holmes.
“You could say we fell off a cliff, but we don’t know what’s at the bottom of the cliff here,” she says.
“I think that has surprised us in terms of how quickly it happened. It’s definitely not the best-case scenario we were looking at — it’s closer to the worst-case,” she says.
Scientists say we can certainly expect more and more of these records to be broken as the year goes on and into 2024.
But it would be wrong to call what is happening a “climate meltdown” or “runaway warming,” warns Dr. Otto.
We are in a new era, but “we still have time to secure a livable future for many,” she explains.
Additional reporting by Mark Poynting and Becky Dale