The year 2024 was the hottest globally since records began – and the heating climate phenomenon El Niño also contributed to this. Although this time it was relatively weak, in combination with the greenhouse effect it led to maximum temperatures due to the now immense amounts of CO₂ in the atmosphere. But in the coming decades, El Niño and its more chilling counterpart, La Niña, could escalate to new extremes, a new study suggests.