Why 2023 was the warmest year ever, and what happens now
Context- The year 2023 was the warmest on record since 1850, surpassing the previous record set in 2016, according to Europe’s Copernicus Climate Change Service (C3S). The temperatures in 2023 were likely the highest for any year-long period in the last 100,000 years. The year was 1.48°C warmer than the 1850-1900 pre-industrial average and 0.17°C warmer than 2016. The World Meteorological Organisation (WMO) had predicted in November of the previous year that 2023 would be the warmest year on record, a prediction that was confirmed by the data from November and December.
The escalation in temperatures in 2023 led to an increase in extreme weather phenomena globally, encompassing heatwaves, floods, droughts, and wildfires. Specifically, Canada experienced its most devastating wildfire season ever recorded from May to September, with over 45 million acres being consumed by fire.
Tumbling records
- In 2023, climate records were broken due to an exceptional heat spell. For the first time, every day of the year exceeded 1°C above the 1850-1900 pre-industrial level.
- About half of the days were more than 1.5°C warmer, and two days in November were over 2°C warmer. However, this doesn’t mean that the long-term warming thresholds of 1.5°C and 2°C set by the 2015 Paris Agreement have been breached. These thresholds refer to average global temperatures over 20-30 years.
- The global daily average sea surface temperature (SST) also reached record highs since mid-March 2023, leading to marine heatwaves in the Mediterranean, the Gulf of Mexico, the Caribbean, the Indian Ocean, the North Pacific, and much of the North Atlantic.
- Furthermore, the sea ice extent in Antarctica reached a new low in September, with an annual maximum of 16.96 million sq km, which was 1.03 million sq km less than the previous record low set in 1986.
Why was it so hot?
- The primary cause of the extreme warming is the rise in greenhouse gas concentrations in the atmosphere. Greenhouse gases, such as carbon dioxide and methane, along with water vapor, trap the Sun’s energy in the Earth’s system, leading to warming.
- Since the industrial revolution, human activities, particularly the burning of fossil fuels like coal, oil, and gas, have resulted in unprecedented levels of these gasses being released.
- This has caused rapid warming of the planet, especially in recent decades. In 2023, the concentrations of greenhouse gasses reached their highest recorded levels, with carbon dioxide concentrations being 2.4 parts per million (ppm) higher than in 2022, and methane concentrations increasing by 11 parts per billion (ppb), according to the C3S and the Copernicus Atmosphere Monitoring Service (CAMS).
- The re-emergence of El Niño last year, following a seven-year hiatus, had a significant impact. El Niño is characterized by an unusual warming of surface waters in the equatorial Pacific Ocean.
- This phenomenon heightened the probability of shattering temperature records and intensified heat extremes in various regions of the world and the ocean.
What could happen now?
- Scientists predict that 2024 could potentially be even hotter than 2023. Historically, extremely hot years have often started in an El Niño state.
- However, El Niño didn’t begin until around July last year, indicating that it wasn’t the main factor behind the unusual heat at that time, according to Emily J Becker, a climate scientist at the University of Miami.
- Consequently, 2024 could surpass the heat records of the previous year. Becker stated that it’s highly likely that 2024 will be among the top three hottest years, if not the hottest.
- There’s also a possibility that for the first time, the next year could exceed the 1.5°C warming threshold throughout the entire year. The World Meteorological Organisation (WMO) reported in its 2023 State of Global Climate report that there’s a 66% chance that at least one year between 2023 and 2027 will cross this threshold.
- A long-term breach of the 1.5°C limit could trigger more severe impacts of climate change, including increased frequency and severity of droughts, heatwaves, and rainfall. To prevent this, urgent measures, including cutting greenhouse gas emissions, need to be implemented, which hasn’t been adequately done so far.
Conclusion- The escalating global temperatures, marked by 2023 being the warmest year on record, are a stark reminder of the urgent need to address climate change. The increasing concentrations of greenhouse gasses, primarily due to human activities, are driving this unprecedented warming. The onset of El Niño has further intensified the situation.
It highlights the critical need for immediate and effective measures to reduce greenhouse gas emissions. The world’s response to this crisis will determine the future of our planet.
