Nearly 70 million people, and still growing

The United Kingdom is home to about 69.7 million people in 2026, and unlike much of Europe it is still growing. The UN’s medium projection adds another 5.7 million by 2050, taking the country to 75.4 million¹.

Britain’s own statisticians are far less sure about that. The Office for National Statistics (ONS) projects about 72.5 million by mid-2050, roughly half the growth the UN expects, with the population peaking in 2054 and then starting to fall². Both agree on where the country stands today. A provisional count put it at 69,487,000 in mid-2025, within 1% of the UN’s figure⁴. They disagree on how many people will move here.

Almost all of the growth now comes from immigration

Births and deaths have all but cancelled each other out. In the year to mid-2025 the UK recorded about 653,000 births and 651,000 deaths, a natural increase of only 2,000 people across the whole country⁴. The ONS expects deaths to overtake births from 2026². From then on, the UK grows only if more people arrive than leave.

That is why the two projections split. Women in the UK have between 1.4 and 1.53 children on average, depending on whose estimate you use, well short of the roughly 2.1 that keeps a population steady on its own¹². So the 2050 figure comes down almost entirely to one assumption about migration.

And migration has swung hard. Net migration peaked at a massive 944,000 in the year to March 2023, then fell to 331,000 in 2024 and 171,000 in 2025, a drop of more than four-fifths in under three years³. The UN’s projection, finished before that fall, still assumes about 364,000 a year¹. The ONS assumes 230,000 a year over the long term², which is how it ends up about 3 million people lower.

England holds 85% of the people

Most of the UK is England. At mid-2024 it had 58.62 million people, against 5.55 million in Scotland, 3.19 million in Wales and 1.93 million in Northern Ireland².

The four nations are on different paths, too. England keeps growing for another 30 years, to a peak of 62.1 million in 2056. Scotland peaks at 5.6 million as early as 2033, Wales at 3.2 million in 2035 and Northern Ireland at 1.9 million in 2031². A UK total that is still rising hides three smaller nations that are close to turning.

An eighth of the world’s blanket bog

The UK holds about 13% of the world’s blanket bog, the thick, waterlogged peat that forms on cool, wet hills⁵.

Together the UK’s peatlands hold at least 3.2 billion tonnes of carbon. Losing just 5% of it would release as much as the whole UK emits in a year⁵, which implies the full store is worth roughly 20 years of the country’s emissions. Drained bogs dry out and the carbon escapes into the air, adding to the world’s CO2 emissions. Healthy, wet ones keep it locked away.

What 70 million Britons draw from other countries’ land

If everyone in the world lived like the average person in the UK, humanity would need 2.43 Earths⁸. Each Briton uses about 3.65 global hectares of productive land and sea a year, while the UK’s own land renews only 1.09 hectares per person⁸. The country runs a deep ecological deficit, and makes up the difference with imports.

Carbon is the biggest slice, 1.44 Earths. That’s the forest that would be needed to absorb the carbon dioxide from the fossil fuels the UK burns. Cropland adds another 0.45⁸, and much of that land isn’t in Britain at all: about 11 million hectares of farmland abroad grow food and animal feed for the UK⁷.

Offshore wind now makes a fifth of the UK’s electricity

The biggest driver of that footprint is starting to move. Offshore wind generated 52 terawatt-hours in 2025, nearly a fifth of the UK’s electricity and enough, by the Crown Estate’s reckoning, to supply 15.5 million homes⁶. The latest auction awarded another 8.4 gigawatts of capacity, the largest offshore wind auction in Europe⁶.

Electricity is only part of the carbon slice, though. Heating, transport and the imported food behind the cropland figure have changed far less.

Where the UK is heading

By 2050 the UK will probably have somewhere between 72.5 and 75.4 million people, and which end it lands at depends on migration policy more than anything happening in maternity wards. If net migration stays near 2025’s 171,000, a rough extrapolation rather than a forecast, the country would grow more slowly than either projection and would likely start shrinking sooner.

Either way, the number of people matters less to the UK’s footprint than how they live. The country already uses more than three times the biocapacity its own land provides, so the bigger question for 2050 is whether the shift that has begun in electricity reaches heating, transport and food.