The World Meteorological Organization says the global average temperature for July 2023 is confirmed to be the highest on record for any month.
“The month is estimated to have been around 1.5 degrees warmer than the average for 1850 to 1900s. So, the average of pre-industrial times,” said Samantha Burgess, deputy director of the Copernicus Climate Change Service at the European Centre for Medium-Range Weather Forecasts.
Some measurements began in 1850, but it was not until 1880 that scientists started to estimate average temperatures for the entire planet.
Burgess said scientists who look at historical and paleoclimate and proxy records from cave deposits and other calcifying organisms, such as corals and shells, find that the observational records go back tens of thousands, if not hundreds of thousands of years.
“So, the longest records we have are ice core records that go back 800,000 years, which give us changes in concentrations of the ratio of carbon dioxide and oxygen in the atmosphere.”
She noted that the United Nations’ Intergovernmental Panel on Climate Change’s sixth assessment report found it has not been this warm, combining observational records and paleo-climate records for the last 120,000 years.
The WMO says that heat waves were experienced throughout July in multiple regions of the Northern Hemisphere, including southern Europe, and that temperatures well above average occurred over several South American countries and around much of Antarctica.
“We know from our long-term monitoring of the climate that the Earth has been warming since pre-industrial times. And we are seeing this as a clear and dramatic warming, decade on decade, and has been since the 1970s,” said Chris Hewitt, director of climate services for the WMO.
He said 2015 to 2022 were the eight warmest years on record, going back 170 years. That, he said, happened despite persistent La Nina conditions, which cause cooler than normal waters in the tropical Pacific Ocean.
On the other hand, he said that El Nino conditions, which lead to warmer than average sea surface temperatures, were developing now in the tropical Pacific, with global temperatures likely to peak in 2024.
“It is very likely that one of the next five years will actually be the warmest on record and a 66 percent chance — and more likely than not — that we will temporarily exceed 1.5 degrees of pre-industrial value.
“So, the Paris agreement will temporarily exceed 1.5 degrees for at least one of the next five years,” he said.
More than 190 nations and the European Union who joined the landmark 2015 Paris Agreement committed to keeping global warming to well below the 2 degrees Celsius level, while pursuing efforts to limit the temperature increase to 1.5 degrees Celsius.
“I know this is not good news,” said Hewitt. “This extreme heat should not come as a surprise, though really, it is consistent with what scientists have been predicting for years. Unless we decrease the greenhouse gases, we will continue to exceed that 1.5-degree limit.”
Burgess noted that there was a direct correlation between the concentration of greenhouse gas in the atmosphere, which leads to global warming, and the impacts on air temperature, sea surface temperature and land temperatures, as well.
She warned of dire consequences “for both people and the planet exposed to ever more frequent and intense extreme events.”
“The impact of deforestation means that we will have less biodiversity and less of the carbon sink in forests to draw down that carbon from the atmosphere,” she said.
“So, ultimately, the less trees and the less organisms that photosynthesize means the less ability the planet will have to have a natural way of removing greenhouse gas concentration from the atmosphere.”
Hewitt agreed that the warming temperatures “will cause problems for various habitats.”
He said it was important “to keep monitoring the climate system, increase the observations of the climate system … and provide early warnings” around the world.
But ultimately, “We need to reduce the greenhouse gases, and we need to be prepared for heat waves, droughts, whatever it might be,” to protect ourselves from “the impacts of the changing climate,” Hewitt said.