That depends. If you're talking about the environment in general (e.g. that it's in danger due to pollution), then no. But if you're talking about a habitat of sorts (e.g. where a bird lives is its "environment"), then yes.
Cylinders.
boats
McDonald's
Martinez's
cobwebs
You wouldn't pluralize "processing", but you would pluralize "process" making more than one process "processes".
Handkerchiefs is correct.
To pluralize the surname "Fourness," you would simply add an "es" to the end, making it "Fournesses."
Sirs is the plural of sir
To pluralize a surname like Folisi, simply add an "s" to make it Folisis.
The plural form of panic is panics.
Do you mean, "How do you pluralize the phrase 'follow God's word' ? 1) Follow the words of God, or 2) Follow God's words.