The world got its first preview last month of what summer will be like at 1.5 degrees of global warming — a threshold that scientists warn the planet should stay under, yet one that it has flown increasingly close to in recent years.
The average global temperature in July, the hottest month on record by far, was around 1.5 degrees Celsius warmer than the pre-industrial era that ended in the mid-to-late 1800s, the European Union’s Copernicus Climate Change Service reported Tuesday.
The announcement came after a series of deadly heat waves and remarkable record-breaking temperatures for several continents, as well as unprecedented ocean heat around the globe. Copernicus scientists say it’s the first summer month that has surpassed 1.5 degrees, offering a glimpse of future summers.
The 1.5-degree threshold is significant because scientists consider it a key tipping point for the planet, beyond which the chances of extreme heat, flooding, drought, wildfires and food and water shortages will become even more unfavorable for life as we know it.
It’s the goal that scientists chose in the landmark 2015 Paris Agreement to minimize the damage of the climate crisis while affording time to wean society and the economy off planet-warming fossil fuels.
It’s also not something that’s tracked by the day or month. Scientists are particularly concerned that global temperature will stay above 1.5 degrees for the long term. Through 2022, the world had warmed around 1.2 degrees.
“While breaking the 1.5-degrees-Celsius threshold for a day or a week or a month is not the same as breaking it for the long-term average, it is important to monitor how frequently, and for how long, we exceed this threshold,” Rebecca Emerton, scientist with Copernicus, told CNN. “As temperatures continue to rise, the effects will continue to become more serious.”
The last few years have made it abundantly clear that the world is already feeling alarming effects of the climate crisis that many are not prepared for. If the planet continues to heat up, Emerton said the world will face even more extreme weather than what much of the planet has already experienced.
“We’ve seen the impacts these kinds of events are already having on people and on our planet, and so every small part of a degree of warming is significant,” Emerton said.
According to Berkeley Earth, an environmental data nonprofit, there have only been 10 other months that were warmer than 1.5 degrees Celsius above their historical average, with March 2023 being the most recent. Before that, the other months that have been 1.5 degrees warmer than pre-industrial times have occurred during winter or early spring.
Berkeley Earth Lead Scientist Robert Rohde said surpassing 1.5 degrees Celsius in July is the first time that threshold has ever been crossed during the summer in the Northern Hemisphere, which makes this a critical moment for the planet.
“While the past unusually warm winters are notable, observing extreme warmth in summer is likely to have greater direct impacts on people’s lives,” Rohde, who is not involved with the Copernicus report, told CNN. “Adding 1.5 degrees Celsius in winter makes for a mild winter but doing it during summer can give rise to unprecedented extremes.”
Although Rohde said it is likely that 2023 will be the warmest year on record, it’s unlikely that 2023 as a whole will be 1.5 degrees warmer than pre-industrial times.
“The year-to-date average is still below 1.5 degrees Celsius, and we find it unlikely that the rest of 2023 will be warm enough to bring the whole year average above 1.5,” he said.
Copernicus scientists noted that as El Niño continues to develop, the world may witness more of these unprecedented temperature breaches.
“Even if the climate crisis does not accelerate, but continues on its current trajectory, we will see more days, weeks, months and years with record-breaking temperatures, and other impacts on our Earth system,” Emerton said. “We need to be doing all that we can to reduce emissions and limit future warming.”