If the world is strategic about which power plants we retire early and which ones we merely regulate, a new study predicts we could significantly cut our fossil fuel emissions while improving air quality in the short term.

Combined with strict climate mitigation policies, these public health policies could save up to 12 million lives and avoid 18 percent of future CO2 emissions.

These estimates are based on real-world data from 2010 to 2018, which have been extrapolated out into the coming decades. During this eight-year period, researchers calculate there were more than 800,000 premature deaths each year that were related to air pollution from fossil fuel plants.

About 92 percent of these deaths occurred in lower income or emerging economies, such as China, India, and nations in Southeast Asia. Outside of Asia, the Middle East and Africa experienced the most power plant pollution-related deaths.

Unsurprisingly, these are also the very regions of the world where power plants are the newest, the least efficient, and the least regulated. Energy demand in these parts is also growing rapidly.

In India alone, for instance, power plant emissions are projected to quadruple between 2010 and 2050 under the status quo, which will inevitably mean more deaths in the future.

If these super-polluting plants can be retired early or run with stronger pollution controls, new models suggest we could "substantially reduce the health burden under the same climate-energy and clean air pathway" by 2050.

Today, the most ambitious climate mitigation strategies don't see air pollution-related deaths dropping significantly until about halfway through the century. In the meantime, millions of people are expected to die from breathing bad air, especially in Asia.

If we can target the most polluting power plants now, researchers think we could avoid many of these deaths.

According to a worldwide database of power plants, known as the Global Power Emissions Database, the biggest 'super-polluting' plants today are located in the Middle East, India, and Africa.

Coal-fired power plants have historically been the worst offenders for both the climate and our health, so focussing on them first will be key. In 2010, these specific energy plants were responsible for nearly 80 percent of all power-related air pollution deaths, researchers say, despite contributing less than half of the world's energy output.

If these coal-fired plants can be retired early, made more efficient, or have carbon capture technology installed, the benefits to public health could be seen almost immediately.

"In contrast to the health benefits of ambitious climate targets which occur mostly after 2030, the deployment of pollution control technologies – focusing on reducing the end-of-pipe emissions – can effectively and immediately lower pollution emission intensities," the authors write.

"Indeed, widespread deployment of strong pollution controls in the near-term can mostly avoid increases in PM2.5-related deaths in 2030 and 2050 even where climate mitigation is weak."

This means even if energy demands continue to increase, populations continue to grow and age, and climate change mitigation remains limited, we can still significantly improve human health in the short term.

Combined with strict climate mitigation policies that keep warming below 1.5 degrees Celsius, there are benefits to human health and the health of the planet.

Under this scenario, even if power plants are not retired early but are only regulated more strictly, models suggest up to 6 million pollution-related deaths and 235 gigatonnes of carbon emissions could be avoided between 2010 and 2050.

If power plants are retired early, on the other hand, that number jumps to 12 million deaths prevented and 278 gigatonnes of carbon emissions avoided.

Because India suffers 45 percent of the model's pollution-related deaths, while Asia and China take on four-fifths of the rest, that means that a high proportion of deaths could be avoided just in those places alone.

The findings suggest climate-mitigation policies on their own are not enough to save human lives from air pollution, at least in the short term.

"Rather," the authors write, "pollution controls and strategic retirements of the most-polluting and harmful power plants may ultimately determine the extent to which health co-benefits are realized."

Our health and our planet's health really are intimately intertwined.

The study was published in Nature Climate Change.