Climate Alarm: Global Temperatures on Track to Breach 1.5°C Threshold by 2028

Redacción HC
30/08/2024

In a stark new forecast, the World Meteorological Organization (WMO) warns that the world is likely to exceed 1.5 °C above pre-industrial temperatures — at least temporarily — within the next five years. This threshold, central to the Paris Agreement, is intended to prevent irreversible damage to the planet. While surpassing it for a single year does not technically violate the agreement, doing so repeatedly or for a multi-year average could signal a dangerous new climate reality.

The WMO’s latest decadal outlook, released in June 2024, combines over 200 simulations from leading global climate centers, including the UK Met Office, to predict short-term temperature trends and their implications. The findings underscore the urgency of reducing greenhouse gas emissions and investing in adaptive infrastructure — especially as the risk of record-breaking heat increases.

How Likely Are We to Cross the 1.5 °C Limit?

According to the WMO’s report, the odds are higher than ever:

• 80% chance that at least one year between 2024 and 2028 will exceed 1.5 °C above pre-industrial levels.
• 86% chance of any single year in that window crossing the threshold.
• 47% chance that the five-year average from 2024 to 2028 will surpass 1.5 °C — and a 70% probability for the 2025–2029 average.

These figures highlight a steep rise in likelihood compared to just a few years ago. For context, the chance of breaching 1.5 °C in any given year was negligible before 2015, ~20% between 2017 and 2021, and 66% in 2023.

The Arctic Is Heating Fast — and That Affects Everyone

One of the most concerning projections in the WMO report is the Arctic's acceleration:

• The region is expected to warm 3.5 times faster than the global average.
• The Arctic mean temperature could reach 2.4 °C above the 1991–2020 baseline by 2028.

This rapid warming can disrupt global weather patterns, accelerate ice melt, and amplify sea level rise. Arctic changes also have knock-on effects on jet streams, potentially intensifying heatwaves and cold spells in the Northern Hemisphere.

Could We Hit 2 °C in a Single Year?

While still unlikely, the WMO estimates a 1% chance that global temperature in a single year will reach or exceed 2 °C before 2030. This level of warming was once considered remote — now it’s in the realm of possibility.

Each tenth of a degree matters, increasing the odds and intensity of extreme weather events. Scientists note that every increment of warming leads to:

• More frequent and severe heatwaves
• Increased risk of extreme rainfall and drought
• Escalation of wildfire events worldwide

“It’s like adding pressure to a system already on the brink,” said a WMO spokesperson. “We’re not just warming — we’re pushing climate extremes further and faster.”

The Role of Climate Models and Forecasting

The WMO’s predictions stem from a multi-model ensemble approach, integrating over 200 simulations from climate centers worldwide. The models are tested using historical data to ensure reliability and reflect seasonal variability, ENSO cycles, and regional emission trends.

• The baseline for comparison is the 1850–1900 period, in line with the Paris Agreement.
• Forecasts are built on observational datasets and short-term climate drivers such as El Niño, aerosols, and land use change.

Although temporary breaches of 1.5 °C are not violations of the agreement (which is based on multi-decade averages), the growing frequency of such events adds pressure on policymakers to act.

Implications for Policy and Preparedness

1. Reassessing Climate Strategies

A year above 1.5 °C may not break the Paris Agreement, but it undermines its credibility and signals a shift in global climate dynamics. As the odds of a multi-year breach grow, nations must reassess and strengthen their Nationally Determined Contributions (NDCs).

2. Infrastructure Adaptation Is Urgent

Heatwaves are no longer rare events. Cities must prepare for:

• Increased health emergencies
• Water scarcity in agricultural regions
• Pressure on energy grids and public transport
• Wildfire risks in new regions

Regions without cooling infrastructure or access to emergency services are especially vulnerable.

3. Early Warning and Rapid Response

The WMO urges:

• Enhanced climate monitoring and forecast dissemination
• Clear risk communication to citizens
• Rapid integration of forecasts into public health, agriculture, and disaster management plans

Short-term predictions can help reduce the impact of climate extremes if matched with swift government response.

Conclusion: We Are Entering the "Era of Exceedance"

Crossing 1.5 °C, even briefly, is no longer theoretical — it’s imminent. The data underscores that global warming is accelerating, with compounding impacts on natural systems, economies, and public health.

If there’s a message to take from the WMO’s forecast, it’s this: we are running out of time to treat climate warnings as hypotheticals. The 2024–2028 period will be critical in shaping not just the next climate agreements, but the future we inhabit.

Topics of interest

Climate