Record heat and moisture seen globally in 2024

If you haven’t already heard, 2024 has officially come in as the warmest year on record globally, surpassing the previous record set just one year earlier. It was the first year with an average temperature that exceeded the 1.5 degree Celsius threshold set by the Paris Agreement. While there is nothing specific about 1.5 C, it is and was a symbolic value or target to try not to achieve. Temperatures across the different data sets ranged from 1.46 C above the pre-industrial average, to 1.62 C warmer. The earth had record-breaking heat for 14 straight months from June 2023 to July 2024. July 2024 global temperatures was reported to be the hottest month in at least the last 175 years.

Berkeley Earth reported 24 per cent of the Earth’s surface saw record-breaking annual temperatures, which impacted around 3.3 billion people. There were 104 countries which reportedly set new national annual average temperature records in 2024, including Canada.

While land temperatures were at record highs, so were ocean temperatures. The record global ocean temperatures brought on the fourth recorded global coral bleaching event, which killed off significant portions of the global coral. It was estimated that 40 per cent of the southern Great Barrier reef died during this event.

For those who don’t trust the different agencies that record global temperatures, the University of Alabama in Huntsville, which uses global satellites to record the temperature of the lower eight kilometres of the atmosphere, also reported that 2024 was easily the warmest year in their data set, going back 46 years.

Another way to look at global temperatures is to count how many national or territorial all-time heat records were broken. In 2024, 22 nations or territories broke national heat records, with no national cold record set. If we look at monthly records, there were 202 monthly heat records broken and just three cold records.

Global carbon dioxide levels reached 424 parts per million in 2024. To put that in perspective, when I started writing weather articles back in 2004, global CO2 levels were 378 ppm, and I remember making a big deal about breaking 400 ppm in 2015.In addition to being the warmest year on record, 2024 was also the wettest year on record, surpassing 2016. For the first time in the last 85 years of records, atmospheric moisture averaged over one inch or 25 mm. The top four wettest years on record have been: 2024, 2016, 2023, 2019. Not surprisingly, some of the top weather stories of 2024 have to do with record rainfall and flooding.

What is the outlook for 2025? Forecasters are calling for a less than five per cent chance of 2025 breaking the 2024 record. Thanks in part to a weak La Nina or cool phase of the tropical Pacific, they think this year will come in as the third hottest year on record, behind 2024 and 2023.

Now on to our look at global ice coverage. In the Arctic, thanks to near record warm temperatures, the minimum sea ice coverage was the sixth-lowest on record. The summer period saw record precipitation across the region. Combining the moisture with the heat and the measure of summer greenness was the second highest in the last 25 years. The southern Northwest Passage through Canada was clear of ice starting in late August, and reported the lowest ice levels on record.

In the south around Antarctica, sea ice coverage continued at record low levels for much of 2024, coming in with the second-lowest coverage on record. The loss of ice has slowed over the southern hemisphere summer, with December 2024 reporting the ninth-lowest ice coverage on record.

Now on to some of the big weather stories over the past year from around the world. Starting in South America, Brazil saw some of its worst flood and drought in 2024. In May, southern Brazil saw heavy rain that brought severe flooding that led to the collapse of a hydro dam. Almost half a year’s worth of rain fell across the region in only one week. Meanwhile, almost 60 per cent of Brazil recorded its worst drought since record keeping began. The Paraguay River, which feeds the worlds largest tropical wetland, fell to its lowest point in the last 120 years. Drought conditions also brought record breaking wildfires. Luckily, widespread rains moved in late during the fall of 2024 which will hopefully break the two-year drought.

In the Middle East, rain was also one of the top weather stories. In April, the United Arab Emirates received almost a full year’s rainfall in just one day, thanks to a cut off low that formed over the region that helped to fuel convection. Rainfall totals were as high as 259.5 mm. Dubai airport reported 160 mm of rain, which was what they’d ordinarily expect over the course of a year and a half. If this same type of event had occurred across the Prairies, we would have seen 600 to 800 mm of rain. The heavy rain brought widespread flooding, with international flights having to be cancelled.

Across Africa there was also unusual rainfall, and just like Brazil, there was severe drought too. Namibia declared a state of emergency in May as the worst drought in a century gripped the country. Meanwhile, tropical rainfalls were displaced well to the north which ended up bringing flooding rainfall to the Sahara Desert for the first time in over 50 years. Satellite estimates showed some regions seeing up to 200 mm of rain over a two-day period in September. The rainfall caused a large portion of the desert to show up green on satellite imagery over the next few months.

Author: Daniel Bezte is a teacher by profession with a BA in geography, specializing in climatology, from the University of Winnipeg. He operates a computerized weather station near Birds Hill Park, Man.

Tags: rain, carbon dioxide, weather, drought, heat, temperature