A sequence of climate records for temperatures, ocean heat and Antarctic ice loss has some scientists alarmed. They say their speed and timing are “unprecedented.”
The dangerous heat waves that shake Europe could break new records, according to the United Nations.It is difficult to make the immediate link between these events and climate change, because Earth’s weather and oceans are so complex.Studies are being done, but scientists fear some of the worst-case scenarios are already playing out.
“I am not aware of a similar period in which all parts of the climate system were in freak territory or breaking records,” says Thomas Smith, an environmental geographer at the London School of Economics.
Earth in unknown territory
“Earth is now in uncharted territory” due to global warming caused by the burning of fossil fuels and the heat of the first El Niño event – a natural climate warming system -, explains Paulo Ceppi, Professor of Climate Sciences at Imperial College London.
Here are four records that have been broken so far this summer, and what they mean:
Hottest day on record
The world experienced the hottest day on record this July, breaking the record for the highest global average temperature set in 2016.The average global temperature exceeded 17°C for the first time this year, reaching 17.08°C on July 6, according to the EU’s Copernicus climate monitoring system.
The continuous emissions from the burning of fossil fuels such as oil, coal or gas are behind the warming trend on the planet.This is exactly what was predicted to happen in a world warmed by greenhouse gases, said climate expert Friederike Otto of Imperial College London.“Humans are 100% behind this upward trend,” he said.
“If there is something that surprises me, it is that we are breaking records in June, so early in the year. El Niño normally does not have a global impact until five or six months after the phase begins,” Smith said.
El Niño is the most powerful natural weather fluctuation. It brings warm surface water in the tropical Pacific, pushing warm air into the atmosphere. Normally it increases the temperatures of the planet.
The hottest month of June globally
The global average temperature in June this year was 1.47C above the typical June of the pre-industrial era.Humans began injecting greenhouse gases into the atmosphere when the Industrial Revolution began in the 1800s.
Asked if the summer of 2023 is what he would have predicted a decade ago, Smith replied that climate models are good at predicting long-term trends, but less good at forecasting the next 10 years.“The 1990s models pretty much put us where we are today. But getting an idea of exactly what the next 10 years would look like would be very difficult,” he said.“Things are not going to cool down,” he added.
Extreme marine heat waves
The average temperatures in the ocean have shattered the milestones set for the months of May, June and July. It is approaching the hottest temperature ever recorded. But it is the heat in the North Atlantic that is alerting scientists in a particular way.
“We have never had a marine 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, UK.
In June, temperatures off the coast of Ireland were 4-5C above average, which the National Oceanic and Atmospheric Administration classified as a category 5 marine heatwave, or “beyond extreme”.
Directly attributing this heat wave to climate change is complex, but work is in progress, says Professor Schmidt.What is clear is that the world has warmed and the oceans have absorbed most of that heat from the atmosphere, he explains.
“Our models have natural variability in them, and things are still showing up that we hadn’t anticipated, or at least not yet,” he adds.Schmidt emphasizes the impact this has on marine ecosystems, which produce 50% of the planet’s oxygen.
“People tend to think of the death of trees and grasses when they talk about heat waves. The Atlantic is 5ºC warmer than it should be, which means that organisms need 50% more food to function normally”, he says.
Antarctic Ice Low Levels
The area covered by sea ice in Antarctica is at record lows for July. Missing is an area around 10 times the size of the UK, compared to the 1981-2010 average.Alarm bells are ringing for scientists as they try to find the direct link to climate change.
A warming world could reduce Antarctic ice levels, but the current dramatic reduction could also be caused by local weather conditions or tidal currents, explains Dr Caroline Holmes of the British Antarctic Survey.
He makes an emphasis on clarifying that it is not just another brand that is beaten, destroyed and by a lot.“This is unlike anything we have seen before in July. It’s 10% lower than the previous low, which is huge.
He called it “another sign that we don’t really understand the rate at which the climate is changing.”Scientists believed that global warming was going to affect Antarctic ice at some point, but until 2015 it prevented the global trend in the other oceans.“We could say that we fell down a ravine, but we don’t know what is at the bottom of that ravine,” he says.
“I think this has taken us by surprise because of the speed with which it has happened. It is definitely not the best of scenarios that we are witnessing, it is closer to the worst scenario”, he adds.
We can certainly expect these marks to be broken more and more as the year goes on and we move into 2024, say the scientists.But it would be wrong to call what is happening a “climate meltdown” or “runaway warming,” warns Friederike Otto.We are in a new era, but “we still have time to ensure a livable future for many,” he explains.
