The globe stands at a critical threshold in the race against warming. After reviewing fresh climate data, the World Meteorological Organization (WMO) issued a clear warning: there is a 50% chance that the planet’s average annual temperature will temporarily surpass pre-industrial levels by 1.5°C within at least one of the next five years. This figure refers to the long-term average based on the 1850-1900 baseline and suggests that temperatures could drift above that level more often as time goes on. The Paris Agreement established a target not to reach this level of warming within the century, a goal that has guided international climate policy since it was adopted.
There is also a strong likelihood, at 93%, that at least one year between now and 2026 will set a new record as the warmest on record, potentially displacing 2016 from the top spot.
Even more striking is the 93% probability that the five-year average for 2022-2026 will exceed the 2017-2021 period, according to the Global Annual – Decadal Climate Update published by the United Kingdom Met Office, the principal forecasting center within the WMO network.
The Paris Agreement aims to keep the long-term rise in global temperatures to well below 2°C above pre-industrial levels this century, a target reaffirmed through successive COP sessions. Yet the room for maneuver to stay within 1.5°C continues to shrink.
The bulletin draws on the expertise of renowned climatologists and the most advanced forecasting systems from leading climate centers around the world, providing decision-makers with actionable insights.
Historically, in 2015 the probability of exceeding 1.5°C at any point was nearly zero, but that probability has risen steadily since then.
WMO data further show that the probability of surpassing the 1.5°C threshold for the period 2017-2021 stood at 10%, rising to about 50% for the 2022-2026 window.
Harmful effects for the entire planet
The top scientific assessment emphasizes that the planet is significantly closer to temporarily breaching the Paris Agreement’s lower limit on climate change, and the 1.5°C threshold is not a random number. It marks the point where climate impacts become increasingly harmful for humans and ecosystems alike.
Exceeding the 1.5°C limit triggers a domino effect: without a halt in greenhouse gas emissions, temperatures will keep rising. The oceans will warm and acidify further, ice and glaciers will melt, sea levels will rise, and weather will become more extreme. The Arctic will feel the strongest effects, and what happens there influences global systems.
The United Nations and WMO remind the world that the Paris Agreement sets long-term targets to reduce greenhouse gas emissions globally, with progress aimed at keeping the rise well below 2°C this century and, ideally, around 1.5°C.
Even 1.5°C of warming increases climate-related risks to natural and human systems. Yet to a lesser extent than a 2°C rise, according to assessments by the Intergovernmental Panel on Climate Change.
Continuous increase in temperature
The latest climate forecasts indicate a continuing upward trend in global temperatures. In one of the 2022-2026 years, there is a 50% chance that global warming will exceed the 1.5°C mark relative to pre-industrial levels, according to Leon Hermanson, the UK Met Office forecaster who leads the bulletin discussion.
Even if the 1.5°C threshold is surpassed in a given year, it does not mean the Paris Agreement has already been surpassed. It signals that the threshold could be breached for a prolonged period if emissions remain unchecked.
Among the key takeaways from the bulletin: each year through 2026 is projected to see average planetary surface temperatures ranging from 1.1°C to 1.7°C above pre-industrial levels. Relative to the 1991-2020 baseline, Arctic temperature anomalies are expected to be more than triple the global average.
The bulletin highlights the need for urgent action to reduce greenhouse gas emissions and to accelerate adaptation efforts worldwide, especially in vulnerable regions across North America and beyond.
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