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2024 Breaches 1.5°C Threshold: A Climate Turning Point
Context:
2024—The First Year to Breach 1.5°C: The year 2024 marked a historic yet concerning milestone as it became the first calendar year to breach the 1.5°C global warming threshold above pre-industrial levels (1850-1900 average). The Copernicus Climate Change Service reported that Earth’s surface temperature in 2024 was 1.6°C higher, while the World Meteorological Organization (WMO) concluded the warming was 1.55°C using multiple datasets.
Key Findings – Record-breaking Warmth in 2024:
- Warmest Year on Record: 2024 surpassed 2023 as the warmest year ever, with every month since July 2023—except July 2024—exceeding 1.5°C above pre-industrial monthly averages.
- Exceptional Trends: The warming trend witnessed in 2023 and 2024 is unparalleled in the last decade, indicating an accelerated pace of climate change.
- El Niño and Other Drivers: A mild El Niño, along with unusual oceanic warming systems, an underwater volcanic eruption near Tonga, and reduced sulphur dioxide emissions from shipping, are believed to have contributed to the anomalous warmth.
- Solar Maximum: The Sun’s solar maximum phase during 2024 may have marginally increased the solar energy reaching Earth, adding to the warming.
The 1.5°C Mark – Its Significance and Implications:
- Arbitrary Yet Crucial: While the 1.5°C threshold is an arbitrary marker, it serves as a critical benchmark for climate action. Exceeding it is associated with more severe and frequent climate impacts.
- Paris Agreement Context: The 1.5°C target in the Paris Agreement refers to long-term temperature trends, not individual years. Thus, the 2024 breach does not signify the failure of the agreement but underscores the urgency of climate action to curb rising temperatures.
Rising Global Emissions and Missed Targets:
- Inadequate Climate Response: Despite the 2024 breach, global emissions continue to rise, with current policies falling short of 2030 reduction targets.
- Future Projections: At the present rate of warming (0.2°C per decade), sustained breaches of the 1.5°C threshold are likely within the next decade, making it imperative for nations to enhance their mitigation efforts.
Exceptional Warmth in 2023-2024 – Underlying Factors:
- Historical Comparison: The previous warmest year, 2016, was influenced by a strong El Niño. In contrast, 2023 and 2024’s warmth stemmed from multiple, less dominant factors.
- Tonga Eruption: The January 2022 eruption released vast amounts of water vapor into the atmosphere, potentially amplifying greenhouse effects.
- Regulation Changes: Stricter sulphur dioxide emission standards in 2024 reduced the cooling effects of atmospheric aerosols, contributing to warming.
- Complex Interactions: While the exact causes require further analysis, these factors collectively highlight the intricate dynamics driving global temperature rise.
What Lies Ahead – 2025 and Beyond:
- Expected Trends in 2025: While 2025 is unlikely to surpass 2024 in warmth, it is expected to rank among the warmest years on record, continuing the trend of elevated temperatures.
- Near-term Projections: According to the WMO, annual temperatures could reach 1.9°C above pre-industrial levels in one of the years before 2028. There is also a 50% chance of the five-year average exceeding the 1.5°C threshold by 2028.
- Policy Imperatives: The repeated breaches of critical thresholds demand urgent global cooperation to implement stronger climate policies, accelerate renewable energy transitions, and enhance adaptation measures.
