Global temperatures are more likely to breach the long-term warming threshold of 1.5 degrees Celsius in the next five years, the World Meteorological Organisation (WMO) has warned.
An El Niño weather pattern which is expected to develop in the coming months is partially responsible, WMO scientists says.
During El Niño, warmer waters in the tropical Pacific heat the atmosphere above, lifting global temperatures.
The legally binding international treaty agreed in Paris in 2015, which came into force in 2016, set an overarching goal is to hold “the increase in the global average temperature to well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels.”
World leaders have in recent years stressed the need to limit global warming to 1.5°C by the end of this century, due to the severe consequences outlined by the UN Intergovernmental Panel on Climate Change (IPCC).
The IPPC has warned that crossing that threshold risks unleashing severe impacts, including more frequent and severe drought, heatwaves and rainfall.
The WMO prediction that this could occur within the next five years has prompted repeated calls for action on fossil fuel use, attributed to the main (four-fifths) cause of climate breakdown.
The El Niño "will combine with human-induced climate change to push global temperatures into uncharted territory", WMO secretary-general Petteri Taalas said in a statement.
The weather phenomenon, while separate from climate change, is likely to boost extremes and bring warmer weather to North America and drought to South America, with the Amazon at greater risk of bad fires, the WMO says.
A year of warming at 1.5C could offer an alarming picture of what crossing the longer-term threshold would be like, scientists say.
The prediction is for a 66% chance of temperatures temporarily reaching 1.5C by 2027.
