China’s emissions decline masks growing vulnerability in hydroelectric reliance

According to a recent Bloomberg opinion piece, China — the world’s largest emitter of carbon dioxide — has seen coal consumption decline even as its economy continues to grow, signaling progress in emissions control.

Through July 2025, electricity generation from thermal power stations fell by 1.3%, alongside a 4.5% drop in cement production and a 3.1% reduction in steel output. Given that China accounts for roughly a third of global carbon emissions, these trends are an encouraging sign for climate mitigation.

However, Bloomberg highlights that this apparent success comes with a caveat: the country’s hydroelectric output has underperformed, exposing systemic vulnerabilities in its energy transition.

Despite a one-third increase in hydroelectric capacity since 2020, electricity production from these sources grew only 11% in 2025, while actual hydro generation fell by 27.8 terawatt-hours (TWh) compared to 2024—nearly matching the 37.4 TWh drop in thermal generation.

This underperformance is linked primarily to below-average rainfall in key river basins, notably the Yangtze, which accounts for about 20% of the world’s hydroelectric power.

Bloomberg notes that this is part of a broader climate pattern. Despite localised flooding and typhoons, rainfall in the Yangtze basin in July was 25% below long-term averages, marking the fourth dry year in six.

Hydropower shortfalls necessitate reliance on coal-fired plants to fill the gap, complicating China’s path to sustained emissions reduction.

The analysis further links hydrological trends to China’s own air pollution controls. Over the past decade, reductions in PM2.5 and sulfur dioxide have dramatically improved public health, but may have unintended climatic consequences.

The reflective particulates that once cooled the atmosphere by scattering sunlight are now reduced, potentially contributing to higher temperatures and altered precipitation patterns.

Research from Nanjing Normal University suggests that rainfall in the Yangtze basin increases with industrial pollution; as air quality has improved, the region may be experiencing drier conditions.

This combination of factors raises questions about the assumptions underlying China’s ambitious hydroelectric projects, including the $167 billion Yarlung Tsangpo dam in Tibet.

Planned based on pre-2013 climate patterns—when particulate pollution was more pronounced—the dam represents the culmination of China’s hydroelectric expansion. If current dry trends persist, the system may fail to meet expectations, forcing greater reliance on coal and limiting the country’s ability to manage peak electricity demand during extreme summer heat.

In conclusion, Bloomberg underscores a paradox in China’s energy transition: while emissions decline and renewable energy capacity rises, changing climate patterns and past policy successes may be undermining the reliability of hydroelectric power.

This dynamic underscores the need for diversified energy planning, integrating wind, solar, batteries, and demand management, to safeguard both China’s emissions targets and global climate goals.

By Sabina Mammadli