On 13th July 2026, the Climate Change Committee (CCC) – the Government’s own statutory climate advisers – responded to a new Government climate adaptation package. That response contained a stark admission: the adoption of a “cross-government planning assumption of a minimum of 2°C of warming by 2050.“
Not the 1.5°C limit nations promised in Paris in 2015, but two degrees minimum. By the middle of this century.
What the Government is actually planning for
This 2°C figure comes from the CCC’s May 2026 report, A Well-Adapted UK, and it is a planning assumption for domestic climate adaptation – how high to build flood defences, how much cooling capacity hospitals will need, how resilient the water supply must be. It is not a mitigation target, and the CCC is careful to say that efforts to keep global warming “well below 2°C” must remain a priority even though, in its own words, “the world is not yet on track for this.”
That distinction matters, but it is by no means a source of comfort. The Government’s own official advisers have concluded that global efforts to control temperature rise are falling so far short of the goal that Britain must now plan for an overshoot of the 1.5°C target – and that 2°C is the floor, not the ceiling. The same CCC report does not rule out 4°C of warming by 2100 as a scenario UK infrastructure must be able to withstand.
CCC chair Baroness Brown put it bluntly: heatwaves in England and Wales this year are estimated to have caused over 2,700 deaths, and “the UK is built for a climate that no longer exists.”
The global evidence is no better
Climate Action Tracker, the independent scientific project that has benchmarked national pledges against the Paris Agreement since 2009, publishes the most rigorously sourced information available. On the policies (not merely promises) governments have actually implemented, the world remains on course for around 2.7°C of warming. Including national pledges for 2030 and 2035 barely improves that figure, to around 2.6°C. Even with binding long-term net-zero commitments, the world is still tracking toward roughly 2.2°C. Under the most optimistic assumption imaginable – that every country hits every net-zero target it has ever announced, adopted or merely floated – the median estimate only falls to around 1.9°C.
None of these routes reaches 1.5°C. And the most sobering finding is not the number itself but its direction: warming projections have essentially flatlined for four consecutive years, showing almost no improvement since 2021, even as the visible damage from wildfires, floods and heat deaths has escalated sharply. The Paris Agreement narrowed the gap in its first five years; since 2020, collective global ambition has simply stalled.
This is the shameful truth. Not a conspiracy, but a slow, documented, collective failure of governments to do what they signed up to do – while telling their own populations, and their climate advisers, to start planning for the consequences instead.
Where aviation expansion fits into this failure
In its Sixth Carbon Budget advice, the CCC recommended that no UK airport should be allowed to expand until a UK-wide capacity management framework was in place to control the sector’s emissions and its “non-CO2” warming effects – contrails, NOx and water vapour, which add substantially to aviation’s climate impact but remain excluded from every current offsetting and trading scheme. But by the Seventh Carbon Budget advice in February 2025, that “no net expansion” recommendation had quietly disappeared – within weeks of the Chancellor publicly announcing Government backing for Heathrow expansion, with decisions on Luton and Gatwick following. Analysis by the Aviation Environment Federation estimates that an expanded Heathrow, Luton and Gatwick together would add some 92 million tonnes of additional emissions.
The CCC clearly forecasts that aviation is on course to become the UK’s single largest emitting sector by 2040, overtaking every sector currently decarbonising faster, and it says plainly that the cost of decarbonising flying – including its non-CO2 effects – should be reflected in the cost of a ticket, specifically in order to manage demand growth. With its own advisers saying aviation growth needs to be constrained to meet the UK’s climate obligations, the Government has chosen to approve, and pursue, the opposite.
A test of sustainability, not sentiment
The United Nations Brundtland Commission definition of sustainability refers to development that meets “the needs of the present without compromising the ability of future generations to meet their own needs.”
Apply that test to airport expansion in the UK. Every additional runway slot, every additional flight path over our communities, locks in decades of additional noise and additional emissions, in support of growth which the Government’s own climate advisers say the country can no longer afford – at precisely the moment those same advisers are telling every other part of government to start planning for the world we get when climate promises are not kept.
That is not sustainable development. It is the present generation creating a future we cannot afford, led by successive world governments without the moral courage or determination to act responsibly.