Scientists are predicting that global temperatures are likely to exceed the critical temperature limit of 1.5°C for the first time between now and 2027, with a 66% chance of reaching this threshold. This is due to emissions from human activity and the potentially strong El Niño weather events expected this summer. However, scientists stress that the breach is likely to be temporary and there is still time to curb global warming through cutting greenhouse gas emissions.
Exceeding the 1.5°C limit represents a key milestone in global climate change negotiations, with countries agreeing under the 2015 Paris Agreement to limit global warming to below this threshold. The impacts of warming will become much greater above this level, including more intense storms, longer heat waves and wildfires.
Scientists use the 1.5°C limit as a measure of how much the Earth has warmed or cooled relative to the long-term global average, and it represents a significant change from previous estimates that a global temperature rise of 2°C was the threshold for dangerous impacts. The report stresses that temperatures must remain above 1.5°C for 20 years to say that the Paris Agreement threshold has been exceeded. Even exceeding the threshold for one year is a worrying sign that warming is accelerating.
The report also highlights the consequences of the El Niño weather event, which is expected to bring extra heat to the Pacific Ocean and push global temperatures to new highs. Uncertainty remains high about the occurrence and magnitude of this event, but scientists predict that the Arctic will experience greater levels of warming than many regions, while Northern Europe, including the UK, is likely to see more rainfall from May to September over the next five years.
Overall, the report reinforces the urgency of the need to address global warming and cut greenhouse gas emissions to curb the worst impacts of climate change.