One good way to motivate others to be ecologically conscious is to introduce them to ecologically sustainable products and solutions that they can use without altering their behavior. 

For example, instead of explaining the reasons why they should stop using plastic straws and utensils, why not gift them with a metal straw that they can carry anywhere, so they can use it instead of plastic straws. Or, instead of trying to convince them to save electricity, why not show them more energy-efficient alternatives to their current devices and appliance, and show the potential cost-savings involved. 

By reducing the friction involved on their part or not making it seem like a big deal, perhaps you can nudge their way into ecological consciousness.