- By Georgina Rannard, Erwan Rivault, Jana Tauschinski
- BBC climate reporter and data team
July 22, 2023
Updated 1 hour ago
A spate of climate records of temperature, ocean heat and Antarctic sea ice have alarmed some scientists, who say their speed and timing are unprecedented.
Dangerous heat waves in Europe could break further records, says the UN.
It’s difficult to immediately tie these events to climate change because the weather — and the oceans — are so complex.
Studies are underway, but scientists already fear some worst-case scenarios are emerging.
“I’m not aware of a similar time period when all parts of the climate system were in a record-breaking or anomalous range,” says Thomas Smith, an environmental geographer at the London School of Economics.
“Earth has been in uncharted territory since 2018 due to global warming from the burning of fossil fuels and the heat of the first El Niño – a warming natural weather system,” says Dr. Paulo Ceppi, Lecturer in Climate Science at Imperial College London.
Here are four climate records so far this summer – hottest day on record, hottest June on record globally, extreme ocean heatwaves, record-low sea ice in Antarctica – and what they tell us.
In July, the world experienced the hottest day on record, surpassing the world record average temperature of 2016.
According to the EU climate monitoring service Copernicus, the global average temperature exceeded 17°C for the first time, reaching 17.08°C on July 6.
The ongoing emissions from the burning of fossil fuels such as oil, coal and gas are the reason for our planet’s warming trend.
That’s exactly what was predicted in a world warmed by more greenhouse gases, says climate researcher Dr. Friederike Otto from Imperial College London.
“Humans are 100% behind the uptrend,” she says.
“If anything surprises me, it’s the fact that the records will be broken in June, which is earlier in the year. Typically, El Niño doesn’t really have a global impact for five or six months,” says Dr. Smith.
El Niño is the world’s strongest naturally occurring climate variability. It brings warmer water to the surface in the tropical Pacific and pushes warmer air into the atmosphere. Usually it increases global air temperature.
The global average temperature in June this year was 1.47°C above the typical pre-industrial June. With the onset of the Industrial Revolution around 1800, humans began pumping greenhouse gases into the atmosphere.
When asked if the summer of 2023 is what he would have predicted a decade ago, Dr. Smith that climate models are good for predicting long-term trends, but less good for predicting the next 10 years.
“Models from the 1990s pretty much got us where we are today. But to have an idea of exactly what the next ten years would be like would be very difficult,” he says.
“There will be no cooling off,” he adds.
Extreme marine heatwaves
The average global sea temperature broke records in May, June and July. It is approaching the highest ever recorded sea surface temperature, recorded in 2016.
But above all, the extreme heat in the North Atlantic worries the scientists.
“We have never had a marine heatwave in this part of the Atlantic. I didn’t expect that,” says Daniela Schmidt, Professor of Earth Sciences at the University of Bristol.
It is complex to attribute this heat wave directly to climate change, but this is still being worked on, says Prof. Schmidt.
What is clear is that the world has warmed and the oceans have absorbed most of this heat from the atmosphere, she explains.
“Our models have a natural variability, and things keep popping up that we didn’t anticipate, or at least didn’t anticipate,” she adds.
She highlights the impact of this heat on marine ecosystems, which produce 50% of the world’s oxygen.
“People tend to think of the death of trees and grass when we talk about heat waves. The Atlantic is 5°C warmer than it should be — meaning organisms need 50% more food to function normally,” she says.
Record low Antarctic sea ice
Alarm bells are ringing for scientists as they try to unravel the exact link to climate change.
A warming world could reduce the level of Antarctic sea ice, but the current dramatic decline could also be due to local weather conditions or ocean currents, explains Dr. Caroline Holmes from the British Antarctic Survey.
She emphasizes that this is not just a record that will be broken, but that it will be beaten many times over.
“This is nothing like anything we’ve seen before in July. It’s 10% lower than the previous bottom, which is huge.”
She calls it “another sign that we don’t really understand the pace of change.”
Scientists assumed global warming would eventually affect sea ice in Antarctica, but by 2015 it contradicted the global trend for other oceans, says Dr. holmes
“You could say we fell off a cliff, but we don’t know what’s down here on the cliff,” she says.
“I think that surprised us in terms of the speed at which it happened. It’s definitely not the best-case scenario that we’ve looked at — it’s more like the worst-case scenario,” she says.
We can certainly expect more and more of these records to be broken as the year progresses and into 2024, scientists say.
But it would be wrong to call what’s happening a “climate collapse” or “runaway warming,” warns Dr. Otto.
We are in a new era, but “we still have time to ensure a future worth living for many,” she explains.
Additional reporting by Mark Poynting and Becky Dale