What are the safest and cleanest sources of energy?

Reducing cleanliness to greenhouse gas emissions is misleading to determine the ecological impact. Sure, the importance is extremely relevant but it should not lead to neglecting any other factor. The safety number is misleading too. Of course there is no data on increased cancer risks from radioactivity in the food chain while the same estimated are done for air pollution. That does not seem right. And the dam that broke and killed a lot of people wasn't build to generate hydro-power. There is also a difference in case numbers if such an event happens in a very populous region compared to a small European city with perhaps 20,000 inhabitants.

Every form of energy production has advantages and disadvantages. Overall I don't think the data here can really inform here without digging deeper into the topic. For someone that hasn't informed himself about advantages and disadvantages of energy production regarding to safety and ecological impact, I fear this data is more misleading than enlightening.

Please correct me, isn't biomass (wood, dung, and charcoal) one of the most common ways of cooking in many rural parts of the world? I wasn't aware of its use for energy like electricity for power grids. Is it even efficient and viable?