The global climate system is no longer merely trending upward; it is leaping. According to the UK Met Office’s annual global temperature forecast for 2024, the planet is on course to breach the 1.5°C warming threshold above pre-industrial levels for the first time in a single calendar year. This is not a statistical nuance. This is a physical signal that the Earth’s energy imbalance is accelerating faster than our models had anticipated.
The Met Office, whose HadCRUT5 dataset is among the most reliable in climate science, calculates a mean global temperature anomaly of 1.58°C above pre-industrial levels for 2024, with a 90 per cent confidence interval ranging from 1.43°C to 1.73°C. To put that in perspective: the previous record, set in 2016 during a major El Niño, was 1.28°C. We are now talking about a jump of 0.3°C in seven years. That is roughly the same magnitude as the entire warming of the three decades between 1970 and 2000.
Professor Adam Scaife, head of long-range prediction at the Met Office, put it bluntly: “Records are not just broken, they’re smashed.” This is not alarmism. It is a description of the data. The underlying driver remains the relentless accumulation of greenhouse gases from human activity, mainly carbon dioxide and methane. The current atmospheric CO2 concentration of over 420 parts per million is the highest in at least 3 million years, back when sea levels were 20 metres higher and forests grew on Antarctica.
But there is a compounding factor. The ongoing El Niño in the equatorial Pacific is adding a temporary spike on top of the long-term warming trend. El Niño events release heat from the ocean into the atmosphere, pushing global temperatures up for a year or two. The current event, which began in mid-2023, is expected to peak in early 2024 and then fade. However, even after it subsides, the baseline will have risen. The heat-trapping capacity of our atmosphere is now such that the next La Niña, which usually cools things down, will likely only bring us back to what we used to call a record-hot year just a decade ago.
The consequences are already unfolding. We are seeing marine heatwaves in the Atlantic and Pacific that are decimating coral reefs and disrupting fisheries. Antarctic sea ice extent has reached record lows for this time of year, setting off feedback loops that accelerate ice melt and sea-level rise. On land, heatwaves and droughts are becoming more frequent and intense, as witnessed in southern Europe, South Asia, and parts of South America. These are not isolated events. They are systemic responses to a planet that is running a fever.
From a policy standpoint, the 1.5°C target was always a political threshold, not a physical cliff. The Paris Agreement aimed to limit warming to well below 2°C, with an aspirational goal of 1.5°C. Exceeding it in a single year does not mean the Paris goal is dead, because the agreement refers to a long-term average over decades. But it does mean we are far closer to the edge than we thought. Every fraction of a degree matters. The difference between 1.5°C and 2°C, for example, means twice as many large cities exposed to extreme heat, and a projected loss of practically all tropical coral reefs.
The Met Office forecast is a stark reminder that the window for meaningful action is narrowing. The energy transition away from fossil fuels is not progressing fast enough. Global carbon emissions are still rising, and the emissions gap between current pledges and the reductions needed to hold warming to 1.5°C is vast. Technological solutions like renewable energy, electric vehicles, and carbon capture exist, but their deployment must accelerate by an order of magnitude.
We are caught in a race between our ability to alter the planet’s energy balance and our capacity to change our energy systems. The latest data suggests the planet is winning that race. The sense of calm urgency I have long felt is now verging on alarm. But alarm is not paralysis. It is a call to action. We need a war-level mobilisation of resources, a transformation of our energy infrastructure, and a political consensus that treats climate change as the existential threat it is.
For now, we have a choice. We can treat this forecast as an abstraction, a number on a spreadsheet, or we can treat it as what it is: a warning from the physical world that the comfortable climate we have known is ending. The planet does not negotiate. It simply responds to the physics we impose upon it.
