What is the cleanest burning fossil fuel that produces the least pollutants?

Natural gas is considered the cleanest burning fossil fuel primarily due to its chemical composition and the efficiency with which it burns. It consists mainly of methane (CH4), which, when combusted, produces significantly lower emissions of carbon dioxide, sulfur dioxide, and nitrogen oxides compared to other fossil fuels like coal and oil.

When burning natural gas, the primary products are carbon dioxide and water vapor, resulting in almost no particulate matter or heavy pollutants. This reduction in harmful emissions contributes to better air quality and mitigates the impacts of climate change when compared to other fossil fuels.

The other fuels listed do not share this same level of cleanliness. For instance, coal produces high levels of carbon dioxide and various pollutants such as sulfur and nitrogen oxides, along with particulates that contribute to respiratory problems and environmental damage. Kerosene, while cleaner than coal, still releases significant amounts of carbon emissions and other pollutants when burned. In contrast, nuclear energy, while it has a low emission profile after its lifecycle is considered, is not classified as a fossil fuel.

Therefore, based on the low pollutant output and its relatively higher efficiency when burned, natural gas stands out as the cleanest fossil fuel option available.