I remember that many of these suggestions also appeared under the guise of saving money in this thread…
Small things that make a big difference…
Unfortunately that thread was hijacked by a strange argument that lower consumption, re-use and frugality are anti-Catholic!

It would have been good to have Pope Francis to refer to then.
My parents and grand-parents lived through the depression and many of their attitudes to consumption came from that.
Of course, there is also the financial savings to reducing waste. So when people speak against reducing waste, saying that there are more important issue like helping the poor, I then suggest the savings from reducing one’s waste can be contributed to the poor. Or to any other Catholic issue. Or to pay off one’s debts and help climb out of poverty.
There was a very good episode of Women of Grace on EWTN last year. The guest had thought “thrift” would be a virtue mentioned in the Bible, but she could never find it. Later she came to understand that it is not a virtue at all, though giving to others is.
Another word for “thrift” might be “hording” (which says it all).
It is probably a tempation of all of us who strive to reduce waste to save a good many things we think we might be able to use later – pack-ratting. I plead guilty!!

And since I’m married to another pack-rat, we’re up to our ears in junk. This, of course, is better than simply throwing things away to go to some land fill. However, I guess we need to find a balance – giving some things to the poor, recycling others, reusing what we can, and not feeling bad that the thing we need most right now, which we had in our garage or closet for many years, we gave to the poor or recycled last month.
OTOH, there are misinformed Catholics who think anything smacking of environmentalism or anything besides 100% commitment to the anti-abortion campaign is a sin…or at least a distraction from more important issues. To them I usually say that I have never had an abortion and have always been against it (even before becoming a Catholic), sometimes joining in various parish and other activities against it, but I AM guilty of harms thru my wastefulness and personal contributions to pollution, so for me at least I would like to strive to reduce these. (I also have much more serious sins, such as lack of charity and outright meanness, esp to my closest loved ones, which I also need to continually work on, but that doesn’t stop me from striving to reduce my less serious imperfections or from doing good to others.)
Also, some environmental harms actually cause miscarriages and birth defects, so reducing these would help reduce risk of these harms. And it behooves us, esp pregnant women, to understand these types of issues, so as to avoid or reduce the risk of such harms.
I don’t know why some Catholics disregard the environment so much. It’s true the environment is “not God”; however, it IS God’s creation, which He pronounced good.
Also trapped in the false notion of nature as something well apart from our human condition – beyond the fringes of civilization, the wild (read “useless”) species in wilderness (useless) places – some are unable to grasp that the environment is also the air we breathe, water we drink, food we eat, chemicals that permeate thru our skin, the resources with which we build our buildings and make our products, and the climate in which grow our crops.
I love Pope Francis, who perhaps because he is a scientist, understands the environment and environmental issues better than most people, and how we are highly interconnected and dependent on it. In his first message as pope he revealed this profound understanding:
Please I would like to ask all those who have positions of responsibility in economic, political and social life, and all men and women of goodwill, let us be protectors of creation, protectors of God’s plan inscribed in nature, protectors of one another and of the environment.
To protect creation, to protect every man and woman, to look upon them with tenderness and love is to open up a horizon of hope; otherwise the way is open to destruction and hearts are hardened. Let us not allow the omens of destruction and death to accompany the advance of this world.
I couldn’t believe my ears. I was moved to tears. Habemus Papam!