There's a reason we call it "the blue marble". Effects spread wide enough can be said to be characteristic of the Earth's dynamics without needing to cover 100

There's a reason we call it "the blue marble". Effects spread wide enough can be said to be characteristic of the Earth's dynamics without needing to cover 100.000% of the surface. In the case of the article, if it affects enough of the population, we can generalize without missing the point.