You, me, and everyone else too. Current lifestyles and consumption are overheating the earth and causing droughts and flooding, and as this continues the sea will rise and many will lose their homes. There will be starvation, migration, suffering and conflict. Do you want that to happen?
Changes are needed to stop producing so much of the CO2 gas produced when we burn fuels for heating, electricity, travel, manufacturing, and farming. The necessary basics in life - food, clothing, housing, and medicine - can be created and consumed more efficiently, and many wasteful activities stopped.
Just say yes and see what you can do. Go carbon neutral. Go green.