Answer:
To protect the environment one could reduce the amount of plastic he is using and replace it with recyclable or biodegradable material such as paper, glass or aluminum.
One could also not use electricity when he doesn't need to. By turning off household appliances or lights we can save electricity and thus reduce the waste needed to create electricity. We could also replace our lightbulbs with LED lights that are a lot more power-efficient.
We could also cut animal products from our diet. That doesn't mean cutting it off completely but if we are looking to save the environment eating half as many animal products as before would drastically improve the environment if enough people did it.