Until 2021 China hosted much of the world's mining, using cheap coal and seasonal hydro. Then it shut the industry down.
The ban
Crackdowns began in mid-2021. On 24 September 2021 the NDRC and other agencies published a notice banning new mining projects and ordering existing ones to be phased out, citing energy use and carbon targets.
What happened next
- Miners unplugged and shipped machines abroad. Hashrate fell, blocks slowed for a while, and the difficulty adjustment brought block times back toward 10 minutes. No coins were lost and no rules changed.
- CCAF's mining map showed China's share at effectively zero in July–August 2021, then 22.3% in September 2021 – evidence of underground mining.
- The US EIA notes that US growth was "largely due" to miners relocating from China.
The map today (dated)
CCAF's 2025 survey (data 2024, not a full census) found the US at 75.4% of reported activity, Canada 7.1%, Paraguay 3.4%, Norway 2.8%, Russia 2.3% and the UAE 2.2%. CCAF warns the US share is likely overstated because US firms answered most eagerly.
The lesson
A country can ban mining inside its borders but not stop Bitcoin. The work simply moves. That is what being permissionless looks like in practice.