Smoking a cigarette increases the chance of cancer in those around me. Multiply by the number of smokers.

Making a new coal-burning plant causes cancer and death by emphysema in those around it.

Farting increases global warming, which increases the chance of skin cancer in the world.

Each of those has a net amount of harm (which we can only attempt to quantify), and takes a certain amount of political and physical/economic effort to rectify (which in the case of coal plants, includes alternative types).

So, yes, is this a big deal, overall, or a fart in the wind?