- Georgina Rannard, Erwan Riewoldt, and Jana Taushinski
- BBC weather reporter and data team
A series of climate records on temperature, ocean warming and Antarctic sea ice have alarmed some scientists, who say their speed and timing are unprecedented.
UN says Europe’s dangerous heat could break more records.
Weather and oceans – so complex that it is difficult to immediately link these events to climate change.
Studies are underway, but scientists already fear some worst-case scenarios will emerge.
“I don’t know of a similar period where every part of the climate system was in record-breaking or exceptional territory,” says Thomas Smith, an environmental geographer at the London School of Economics.
“Earth is in uncharted territory” due to global warming from burning fossil fuels, as well as warming from the first El Niño, a natural climate system that will warm from 2018 – Imperial College London climate science lecturer Dr. Paolo Seppi says.
Here Four weather records What’s broken so far this summer — the hottest day on record, the hottest June on record globally, extreme sea heat and record low Antarctic sea ice — and what they’re telling us.
The world experienced its hottest day in July, breaking the global average temperature record set in 2016.
The average global temperature topped 17 degrees Celsius for the first time, reaching 17.08 degrees on July 6, according to the European Union meteorological service Copernicus.
Constant emissions from burning fossil fuels such as oil, coal and gas are behind the planet’s warming trend.
This is what is predicted to happen in a world that is warmed by more greenhouse gases, says climate scientist Dr.
“Humans are 100% behind the upward trend,” she says.
“If I’m surprised by anything, we’re seeing records being broken in June, so early in the year. El Nino usually doesn’t have a global impact for five or six months,” says Dr Smith.
El Niño is the world’s most powerful natural climate change. This brings warm water to the surface of the tropical Pacific, pushing warm air into the atmosphere. This generally increases the global air temperature.
The average global temperature in June this year was 1.47C warmer than the typical June in pre-industrial times. When the Industrial Revolution began in the 1800s, humans began pumping greenhouse gases into the atmosphere.
Asked if he would have predicted summer 2023 a decade ago, Dr Smith says climate models are good at predicting long-term trends, but not so good at predicting the next 10 years.
“The models of the 1990s have gotten us where we are today. But it’s very difficult to have an idea of what the next 10 years will look like,” he says.
“Things are not going to cool down,” he adds.
Extreme heat waves in the ocean
Average global ocean temperatures for May, June and July broke records. It is approaching the highest sea surface temperature ever recorded, which was in 2016.
But scientists are particularly alarmed by the extreme heat in the North Atlantic Ocean.
“We’ve never had an ocean heat wave in this part of the Atlantic. I didn’t expect this,” says Daniela Schmidt, Professor of Earth Sciences at the University of Bristol.
Attributing climate change directly to this heat wave is complex, but that work is underway, says Prof Schmidt.
It’s clear that the world has warmed and the oceans have absorbed much of the heat from the atmosphere, she explains.
“Our models have natural variability in them, and things are still appearing that we haven’t envisioned, or at least not yet,” she adds.
She emphasizes the impact this warming will have on marine ecosystems, which produce 50% of the world’s oxygen.
“When we talk about heat waves, people think of dying trees and grasses. The Atlantic is 5 degrees Celsius warmer – that means organisms need 50% more food to function normally,” she says.
Record low Antarctic sea ice
Alarm bells are ringing for scientists trying to find the exact link to climate change.
A warming world could reduce the extent of Antarctic sea ice, but the current dramatic reduction could be caused by local climate or ocean currents, said Dr. Caroline Holmes explains.
She stresses that it’s not just a record being broken – it’s being broken by a long way.
“It’s nothing like we’ve seen in July before. It’s 10% lower than the previous low, which is huge.”
She calls it “another sign that the course of change is not really understood.”
Scientists once believed global warming would affect Antarctic sea ice, but until 2015 it reversed the global trend for other oceans, says Dr Holmes.
“You could say we fell off a cliff, but we don’t know what’s under the cliff here,” she says.
“I think it surprised us in terms of the speed at which it happened. It’s certainly not the best-case scenario we were looking at — it’s closer to the worst,” she says.
We can expect more and more of these records to be broken as the year goes on and into 2024, scientists say.
But calling what is happening “climate collapse” or “runaway warming” is wrong, 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