Summer of 2023 hottest on record, data show

The Earth has experienced its most scorching summer in the Northern Hemisphere, especially parts of the United States, Europe and Japan, with record-breaking high temperatures, resulting in high sea surface temperatures and low Antarctic sea ice extent, data have shown.

Temperatures have consistently risen this summer. From June to August, the planet had its hottest three consecutive months since records began in the 1940s, according to the European Union-funded Copernicus Climate Change Service, or C3S. The latest month ranked the hottest August by a large margin, but also the second-hottest month, right after July 2023.

The entire month of August is estimated to have been around 1.5 C warmer than the preindustrial average from 1850 to 1900. This year so far is the second warmest on record behind 2016, when there was a powerful warming El Nino event, according to the World Meteorological Organization.

A report in May from the WMO and the United Kingdom's Met Office predicted that there is a 98 percent likelihood that at least one of the next five years will be the warmest on record and a 66 percent chance of temporarily exceeding 1.5 C above the 1850-1900 average for at least one of the five years.

"What we are observing, not only new extremes but the persistence of these record-breaking conditions, and the impacts these have on both people and planet, are a clear consequence of the warming of the climate system," C3S Director Carlo Buontempo said.

The rise of temperatures has now exceeded the threshold set by the Paris Agreement, an international treaty on climate change and reducing carbon emissions, to which 196 parties at the United Nations Climate Change Conference accepted.

"The dog days of summer are not just barking, they are biting," UN Secretary-General Antonio Guterres said. "Climate breakdown has begun." He urged global leaders to take action on climate change and reduce greenhouse gas emissions.

Also, countries in the Southern Hemisphere are experiencing gradually warmer winters.

The world's oceans were the hottest ever recorded, nearly 21 C, and have set high-temperature marks for three consecutive months, the WMO and C3S said.

Also, Antarctic sea ice extent has continued to hover at a historically low level for this time of the year, with a monthly measurement that stands 12 percent below the typical average, by far the largest negative anomaly for August since satellite observations began in the late 1970s, the report said.

Meanwhile, a new WMO report revealed that climate change is significantly impacting air quality, human health and the environment by heightening the intensity and frequency of heat waves, and exacerbating wildfires and desert dust.

Agencies contributed to this story.