Why do humans cut down trees when they are our main source of oxygen?

Look around you. Your walls are probably framed with wood, your floor is probably wood, most furniture is made of wood, the paper you use is partly wood pulp, wood doors, wood trim, kitchen cabinets, etc. Our forests are being managed and replanted, maybe not well, but much better than they were many years ago. Until someone finds a viable and affordable alternative to wood, trees will continue to be used for our comfort.

Trees are not our main source of oxygen. The main source of oxygen is the protists and photosynthetic bacteria of the oceans. A common misconception. Be more worried about what we are doing to the oceans and how that will impact our true oxygen producers.

We actually have many trees in the US ( some places, not so many anymore ) though they are farmed trees destined to become lumber.

If done properly they will replant the trees that have been cut. There are also other plants that give off oxygen, which is why I have a fair number of plants in my house. If you are worried about you oxygen supply get some house plants.

Because money is more important than whether we can breath. They will be taxing us on oxygen soon, whilst building more airports and more toll tunnels, so they can make money while we all suffer the fumes from queues and the on going expense of the toll. They build eco friendly electric cars with batteries which will be far from Eco friendly when they've had their day. They don't care about the environment, they care about how rich they can make themselves whilst flying about in their private jets, believe me they are not squashed in economy, and peeing in a toilet the size of a sardine can, eating plastic food with plastic cutlery and mini drink cans for £5 a pop which wouldn't quench the thirst of a gnat. There have been plenty of ideas for greener fuel and guess what? They tax them. By the way as a tip your 5p bag also works as a hat when it rains (I like to make the most of mine, just remember putting bags over your head causes suffocation so make sure you roll it up over your face or you will suffocate...still I don't think you get taxed on suffocating O_o

That's Life...

Stupidity, greed as wood is a cheap and abundant (or was once) source of which to build cheap buildings without ever thinking of what it would to the Planet and how long it takes for a tree to regrow

Also paper comes from trees . So we need paper. Especially kids that go to school with the note books they write in do there home work and essays in. Paper is important to .