Doing little things makes a big difference. Here are just a few fast ideas to get started:
Don't drive when there is any other alternative. Use the off switch and go outside. Get out of debt. Take more time for connecting face to face in the home neighborhood. Eat food that is local and fresh. Read books about nature. Never have stinky trash. Use only canvas or alternative bags for shopping. Never waste food. Don't buy new when it's more affordable used. Don't waste water. Go to bed earlier. Reduce plastic containers. Demand durable goods. Cut down on meat, fat and grease. Car-pool. Watch birds. Recycle.
For human beings there are no small steps. Just the slightest change in behavior makes a huge impact. It was slowly, over the last two hundred years, that industrialized society made day by day, tiny changes. The result is that the world thrives on greenhouse gases to fuel vehicles, heat and cool surroundings, fertilize, water and eliminate pests in agriculture, create mountains of waste and much more. Each activity became so routine that even today, many remain in denial about the idea that the earth is finite or full.
Yet, people should celebrate that all it takes is small steps. Changing the world for the better can be compared to the moon landing but it is much more important, with an enormous pay off. If humanity is up to it, they should be proud, fierce and determined to take each small step that is a giant leap for all Earth-kind.
The idea that human beings are petty, selfish, arrogant and entitled should be challenged. Humans are quite capable, and indeed, actually thrive and feel better physically, emotionally, mentally and spiritually when they embrace belonging to one another and the world. That humans survived the first hundred thousand years, and that the present mess is most likely a weird blip on the stage of history, is evident when viewing the big picture. It is only quite recently that fossil fuels seemed to be drug of choice for everyone.
More persistent and evident in human history is the human drive to innovate, explore find better ways of optimizing efficiency and taking on great challenges. Discovery language was great. Discovering agriculture went a bit haywire, but is still great. Discovering evolution and DNA, our belonging on the planet-essentially, is very great (and HIGHLY recommended). Discovering alternative ways to produce clean energy, control overpopulation, end poverty and curb all exploitation against one another, and the rest of Earth's systems, is perhaps the greatest of all.
Oh and not having stinky garbage? That is also great. Simply never add food or organic waste of any kind in with the small amount of non recycled waste the household collects. Put all food scraps in the compost bag or sealed bucket. If you live in an urban tower, find the closest person who will be thrilled and thankful to you for providing it weekly to the community garden.