A great thing that you can do for yourself and the Earth is to grow your own food. Even if you live in a small apartment, you can manage to grow sprouts to eat.
If you are fortunate enough to have any space outdoors to grow things, you can grow a lot or all of the food you eat. There are some wonderful videos on youtube about this. A man in Arizona made one of them. It is very encouraging to watch his video about food growing for profit.
He has invented his own hydroponics system and explains how you can make millions of dollars using only an acre of land. That is using his hydroponics system, of course. He shows diagrams of his system and explains how it is basically built. He grows an amazing amount of food in a few feet of space.
He suggests beginning with one hydroponics plant for less than a dollar if that is all of the money that you have available now. He suggests that you use the profits from the one plant to buy more equipment to grow more plants and repeat until you are a millionaire from selling your crops.
The process he suggests works much faster if you have enough money to buy more equipment to begin with. It makes me want to rush out and buy equipment. I actually prefer to learn more about how to grow stuff and operate hydroponics first, though.
Here is a link to his video: https://www.youtube.com/watch?v=9GghlbtGjfk&NR=1&feature=endscreen