2024 set to become hottest year on record

As the clock ticks down the final moments of the year, 2024 is expected to wind up as the world's hottest year on modern record, surpassing the previous record for the second year in a row.

"Here we are again. It's all but stamped and done that 2024 will be the hottest year on record," Kristina Dahl, vice president for science at Climate Central, told Paste BN on Monday. "Having two back-to-back record-breaking years stands out to me as a sign that we are dangerously off track if we want to avoid the worst consequences of warming."

Months of record warm air and ocean temperatures around the world during the first seven months of the year led scientists to speculate this year would be warmer than the last.

"The writing has been on the wall for some time,” said Robert Rohde, chief scientist at Berkeley Earth. "With most of 2024 already recorded, 2024 has maintained a clear temperature lead over 2023.”

Daily air temperatures 6.5 feet above the surface by year since 1979:

“We still need the December readings to fix the final averages, but there is very little doubt at this point that 2024 will have been warmer than 2023," Rohde said. “December would have had to be extraordinarily cool to prevent 2024 from setting a new annual average record."

The final statistics are scheduled to be released Jan. 10, when The National Oceanic and Atmospheric Administration, NASA, Berkeley Earth and others all have agreed for the first time to release the data on the same day, Rohde said.

The January to November average was the hottest on record, according to federal data and the World Meteorological Organization, and December temperatures did little to change the trajectory.

On Dec. 9, the Copernicus Climate Change Service stated it could "confirm with virtual certainty" that 2024 would be the warmest year on record. As of Saturday, Dahl said Copernicus data showed the year-to-date global average was still two-tenths of a degree warmer than last year.

A combination of natural variability and human influences such as greenhouse gas emissions pushed temperatures higher, scientists said this week. The warming temperatures contributed to deadly heat waves and the ripple effects of "massive hurricanes that were made more intense by the climate change and floods that were worsened by climate change," Dahl said.

In a video statement Monday morning, United Nations Secretary General Antonio Guterres underscored the influence of climate change on the world's temperature, noting the top 10 hottest years on record have all occurred in the last decade. "This is climate breakdown in real time."

Heat records in the US and abroad

Records have fallen around the globe throughout the year. For 16 consecutive months – from June 2023 to September 2024 – the global mean temperature likely exceeded anything recorded before, and often by a wide margin, according to the World Meteorological Organization's analysis of global weather data sets.

During the first 11 months of 2024, the globe’s surface temperature was 2.3 degrees Fahrenheit above the 1901-2000 average of 57.2 degrees. It was also the hottest summer on record.

Even though global average temperatures dropped below 2023 records at times during the second half of the year, air and ocean temperatures were still warmer than average overall, based on charts by the University of Maine’s Climate Reanalyzer. The data behind the charts comes from the European Centre for Medium-Range Weather Forecasts, and combines conventional weather observations from around the world and satellite data with a computer model of the Earth to provide a best estimate to fill in the gaps in locations where fewer actual observations are available.

Record-warm temperatures covered an estimated 10.6% of the world’s surface in November, the highest percentage for the month since the start of records in 1951, while record-cold covered only .4% of the globe’s land surfaces, NOAA said. November 2024 was the warmest on record in Asia.

2024 temperatures in the US

While scientists aren't as certain that a new U.S. annual record will be set, the first 11 months of the year were the warmest on record in the contiguous U.S. The average temperature was 57.1 degrees, 3.3 degrees warmer than the long-term average.

NOAA also has reported:

• January to November temperatures were the warmest on record in 22 states and among the three warmest year-to-date periods on record for another 11 states.
• It was the second warmest November on record, just a smidge (.09 degrees) behind the record warm November last year.
• The Gulf of Mexico saw its warmest November on record at 2.95 degrees above average.

Why was 2024 so warm?

Several factors contributed to the warmth, said Jennifer Francis, senior scientist at the Massachusetts-based Woodwell Climate Research Center.

El Niño, a natural marine heat wave in the tropical Pacific, lingered through April, Francis said. “Marine heat waves in other areas – particularly in the North Pacific and North Atlantic oceans – raged through the year, caused mainly by increased heat-trapping greenhouse gases.”

More devastating heat waves over land and water are among the clearest fingerprints of human-caused warming, Francis said. The coming year “will likely keep these headlines coming.”

Human-caused changes to the globe’s climate system also contributed, she said, including shifts in wind patterns that appear to be “reducing clouds that reflect solar energy to space, leading to more surface heating,” and the darker surfaces exposed by melting ice and snow that absorb more sunshine, she said.

Daily sea-surface temperatures by year since 1982:

Climate change 'nudging' natural weather patterns

Scientists are still working to investigate how warmer temperatures are influencing or could influence in the future natural severe weather events such as heat waves, hurricanes and the convective storms that cause heavy wind damage and tornadoes.

The nation saw a near record number of tornadoes this year. And the Atlantic Ocean and Gulf of Mexico were prolific producers of hurricane activity, even though the total number of storms wasn't quite as high as originally forecast in seasonal outlooks.

More than 200 people died as a result of the five landfalling hurricanes in the U.S., the deadliest season on the mainland since 2005. Heat waves after the hurricanes passed, when people had no electricity, often caused a double whammy in impacts, Dahl said. "Those are some of the most disturbing (events) because you've got people without power, without water."

After Hurricane Beryl struck Texas in June, at least 11 people died after succumbing to heat exposure while coping with no electricity. Those victims included 110-year-old Christine B. Davis. She "just couldn't take the heat," said her granddaughter Emma Odom.

“Climate change certainly has its fingerprint on everything in the atmosphere, but hurricane-related signals are harder to tease out," Brian McNoldy, a hurricane research scientist at the University of Miami, recently stated. That's because the period with reliable data is relatively short and there's natural variability between seasons.

More and more studies suggest hurricanes are experiencing higher peak intensities and a higher frequency of rapid intensification. "So, not necessarily more storms, but of the ones that form, they are becoming more likely to become stronger and sometimes in less time,” McNoldy said. “I don’t ever point to climate change as the singular cause of anything (when it comes to hurricanes,) but it’s gradually nudging their behavior, on average.”

Could 2025 be another record setter?

It’s possible that global temperatures may not be quite so high in 2025, particularly if a La Niña develops, scientists told Paste BN this week. It's happened before. World temperatures dipped slightly in 2017 after three record setting years in a row during an intense El Niño in 2015-2016, making 2017 only the second hottest year on record at that time.

“Natural fluctuations in temperature are expected, so 2025 could very well be cooler,” Francis said. However, the World Meteorological Organization recently said the La Niña, a pattern of cooler than normal temperatures in the Pacific Ocean, is likely to be weak and short-lived.

“But until we humans stop dumping greenhouse gases into the atmosphere, the overall trend will continue to climb,” Francis said. “Every broken record, every extreme weather disaster, every diminished coral reef, every coastal flood should sound alarms that our abuse of the Earth is making these events more frequent, more intense, and more destructive.”

Contributing: Karina Zaiets, Paste BN