1. Is a prediction based on linear trends in population and pollution per population and their first order effects. I would grade this is science only.
2. has a lot of predictions and some normative statements based on those predictions. "The oceans will be dead as lake eerie" is science "and it does need saving" is a normative statement synthesizing this guys failed scientific predictions with a philosophical framework, most likely utilitarianism.
3. I would grade the highlighted part as science only. "it is now urgent to..." is a normative statement synthesizing the science this guy is doing, and varied philosophical frameworks most like utilitarianism and rational empiricism.
4. The highlighted part is a normative synthesis of science (what are anti cyclone and what are their physical effects) and philosophy (their effects are "adverse.")
5. is completely descriptive (science)
6. The highlighted part is a normative synthesis of science (predictions about conditions) and philosophy (comparing conditions using "worsen")