This is demonstrably false because our mere existence also gives back to the planet – in default conditions. Uncomfortable topics like human waste (pee / feces), if disposed of properly and given back to forests and fertile lands, definitely falls under the “giving back” category. 
(but not when it’s indiscriminately thrown out in the ocean, along with literal thousands of tons of plastic)
But I wouldn’t dwell on the fact that no matter how hard we try, we end up always taking more than we give. It’s the circle of life – the “simpler” life forms are used to fuel the more “complex” life forms and that has been the case since life at all existed. We’re not the only ones to reap the benefits of our superior intelligence compared to other species around.
A sweet but an ultimately doomed effort. Ego and greed are innate engines of evolution; without them systems get stuck and eventually looted and pillaged by the more savage and unscrupulous elements in the system.
Our life should IMO resemble a sinusoid curve – during some periods we take more, during others we give more. We cannot and should not always put ourselves in service of some invisible society. Sure all those people exist, I don’t doubt that; but how much of them do you meet or care about? And are you really sure what you do is going to affect them positively? Maybe, by skimping on some expenses you’re not saving the planet but are leaving an Indian or Chinese father jobless?
You already were that in my life and we haven’t even met. There are many ways to be an actual positive force. You absolutely are. You don’t have to center your entire existence around this ideal. All things in moderation!
ABSOLUTELY NOT. Please. For years now we have regulations that dog owners have to pick their dog’s poop after them. Why? One of the main reasons was that there are now so many dogs in the cities that the soil in the parks literally cannot handle all the poop!
It’s okay to love animals. I’d probably get physically violent if somebody harms a parrot or a cat in front of me. But animals in inner cities that litter outside – which means dogs in particular! – are becoming more and more of a problem. Plus, irresponsible owners figure they don’t want to care for their dog anymore and they just drive several blocks away and let the dog out and go back. And then you have non-neutered dog procreating with the other street dogs. Then people get attacked by the increasing number of stray dogs as well.
It’s a huge can of worms and I feel people should stop worshipping dogs as much as they do. Love them, sure, but refrain from taking more of them under your roof! I’d go even further: if you live in the inner city you should even be required to have a special permit to own a dog. That permit should likely cost 20,000 EUR and you should also be periodically required to prove that you continue to be a good dog owner. This steep financial penalty would likely fix the problem for decades ahead.
(Unless you live outside the city of course; there the dogs can do no harm to nature since nature there is so much more in area compared to the inner cities.)
Finally, the whole “be ecological citizens” thing I always found to be very hypocritical and very often an empty virtue signalling activity. I think I shared that with you once but it bears repeating – once I drew out a calculator to prove to a teacher that 50,000 people stopping their usage of electric kettles is but a drop in the ocean for less electricity usage and if that just ONE local factory switches to a more eco-friendly manufacturing process they can very easily outweigh what 250,000 to 500,000 citizens can do.
This was proven and backed by math by statisticians and engineers, many times.
Yes, we can be better. Yes, we can try to be less disruptive to the planet’s ecology. But us the regular citizens really can’t do much. There are much bigger entities out there that should lead the way.