Evidence from late 2021 onward shows that China quickly reversed the coal-usage and energy‑intensity constraints that had contributed to power rationing and factory slowdowns, and it did not allow those climate/clean‑energy‑driven limits to cause a prolonged, multi‑year industrial shutdown.

1. The 2021 problem really did stem partly from clean‑energy/dual‑control targets. In September–October 2021, many provinces restricted power to energy‑intensive, high‑emissions industries in order to meet strict “dual‑control” targets on total energy use and energy intensity, which were a key tool for meeting carbon and pollution goals. Analyses note that these dual‑control targets and their over‑implementation were a major driver of the widespread industrial power rationing in 2021. (jorae.cn)

2. Beijing rolled those constraints back very quickly by pivoting hard to coal. Within weeks, central authorities ordered major coal‑producing regions (Shanxi, Shaanxi, Inner Mongolia) to restart and expand mines and to "release advanced production capacity" to ease the shortage, and eased conditions on mine extensions. (adamtooze.com) By November 2021, China’s coal output hit a record monthly high as miners were told to run at maximum capacity; official data show coal production in October–November 2021 at unprecedented levels and coal stocks at power plants rising rapidly as supply tightened constraints eased. (investing.com) For full‑year 2021, China’s coal production reached an all‑time record (about 4.07 billion tonnes), explicitly because the state “encouraged miners to ramp up their fossil fuel output to safeguard the country’s energy supplies.” (sej.org) This is the opposite of letting clean‑energy‑motivated coal limits persist.

3. Policy design was changed so that those energy‑caps wouldn’t keep biting growth. Subsequent policy documents reworked the dual‑control system: a previous national cap on total energy consumption was scrapped, annual energy‑intensity targets were relaxed in favor of a more flexible five‑year goal, and no hard caps were placed on coal consumption or coal‑power capacity—explicitly to give more room to support economic growth and energy security while still pursuing long‑term decarbonization. (asiasociety.org) That institutional change is consistent with Sacks’s view that Beijing “woke up” and would not keep restrictive clean‑energy constraints that risked throttling industry.

4. After 2021, China doubled down on coal for energy security instead of maintaining tight coal limits. In 2022–23, China approved roughly 218 GW of new coal‑fired power capacity and started construction on large amounts of new coal plants, making up the overwhelming majority of global coal‑power construction. (bworldonline.com) In 2024 alone, construction began on about 94.5 GW of new coal plants, the highest in nearly a decade. (reuters.com) Parallel analyses note that coal remains central to China’s energy security strategy and that coal‑fired capacity and coal‑mine development have continued to expand. (chinapower.csis.org) This sustained expansion further confirms that the late‑2021 coal restrictions were not allowed to persist as a binding clean‑energy constraint.

5. There was no multi‑year, climate‑policy‑driven shutdown of large parts of China’s industrial economy. The 2021 power rationing and factory curbs lasted weeks to a few months and were largely resolved by the end of 2021 as coal supply and pricing policy were adjusted. (investing.com) Later disruptions to power supply (e.g., during the 2022 Yangtze drought) were handled by leaning more on coal as the "bedrock of energy security," not by maintaining coal‑usage caps that suppressed industry. (global.chinadaily.com.cn) Over 2022–2024, China’s industrial output and exports continued at large scale despite other headwinds (COVID policy, real‑estate downturn, external demand), and the main energy‑policy trend was ensuring reliability—often by increasing coal capacity—not intentionally shutting down industry for clean‑energy reasons.

Putting this together: the specific late‑2021 clean‑energy/dual‑control‑linked coal constraints were indeed rolled back quickly, and China chose to prioritize energy security and industrial continuity over keeping those limits in place. The feared scenario—multi‑year shutdown of significant portions of the industrial economy because Beijing stuck with those clean‑energy‑motivated coal caps—did not occur. Sacks’s prediction is therefore right.