Reducing emissions by targeting hyper-polluting power plants

A new study suggests that 5% of the world's power plants are responsible for 73% of all electricity-based CO2 emissions.

The journey towards net-zero is underway. Many nations have made some sort of commitment to eliminating CO2 emissions by the midpoint of the century. How that ought to be achieved, however, is a different story entirely.

A recent study published in Environmental Research Letters suggests a new tactic for reducing global CO2 emissions – targeting the hyper-polluting power plant. The study, aptly named Reducing CO2 emissions by targeting the world’s hyper-polluting power plants, found that 17% to 49% of global electricity-based CO2 emissions could be eliminated using this approach.

The study draws its emissions data from an updated version of 2009’s Carbon Monitoring for Action file (CARMA), which tracks CO2 emissions from the world’s power plants. The newest version, created in 2018, “consists of 29,078 fossil-fuel powered plants from 221 countries,” according to the study. CARMA draws from 3 key data sets: plant-level emissions reports, global-plant and company-level data, and country-specific power production data.


In countries like the US, Japan, South Korea, Germany, and Australia, 5% of polluters are responsible for 75% - 89.6% of emissions. This trend scales globally, with the top 5% of the world’s polluters contributing to 73% of all electricity-based CO2 emissions. China’s top 5% is responsible for much less CO2 output – around 24.5% - due to the country’s distribution of emissions evenly amongst different sized plants.

The study goes on to suggest that targeting this top 5% with reforms could significantly reduce global emissions levels. It suggests four key changes along with an estimate of the reduction in CO2. These include lowering intensities to match a national - then international - average, switching to natural gas, and implementing carbon capture technology (with the assumption that 85% of carbon is captured).

The results show that the implementation of all 4 policies could be highly effective in reducing electricity-based CO2 emissions. South Korea, for example, could reduce its electricity-based CO2 emissions by a whopping 76%. Similarly, the US could reduce its carbon output by 63.7%. China, the outlier in this list, would only reduce its CO2 output by 20.7%.

According to the study, implementation of these policies could reduce global electricity-based CO2 emissions by up to 48.9%. Merely switching the world’s plants to natural gas would result in a reduction of 29.5%.

The paper concludes by offering its main takeaway: “Findings suggest that instead of relying on sweeping environmental initiatives, substantial environmental progress can be made through selectively targeting nation’s hyper-polluters – the worst of the worst – that are responsible for the lion’s share of their carbon pollution.”

One key limitation, as the study points out, is the difficulty in enforcing such policy changes at a global scale. Furthermore, some countries benefit much less from such an approach. China may benefit more from targeting 10% of its polluters instead of 5%. This is due to its distribution of emissions across plants.

There is also the issue of data accuracy. The study points out that some plants either do not report their CO2 emissions or they keep them confidential. Thus, the study provides estimates of emissions in the absence of accurate data. The study believes that while some small plants may have been left off the list, the estimates for the largest power plants are reliably accurate.