We know about the consequences, but the question here is not whether we know, but whether said consequences are of any importance or relevance.
Only someone who has absolutely no value for life, whether human or animal or even their own genetic line, would believe such a thing as you just said.
Right now we're doing great damage to the environment, little of which is reversable. We are driving countless creatures towards extinction, undoing hundreds of millions of years of evolution. You could bring back these creatures to life or converse a small amount in captivity, but what would be the point when there is no suitable habitat left for them to live in the wild?
We're not only poisoning the soil we walk on, fowling the water we drink & swim in, polluting the air we breathe, destroying the plants & creatures we share this planet with, but we're even harming ourselves. There are so many ticking time bombs right now in the world, from the consequences of persistent use of low level antibiotics in intensively farmed animals, the constant draining of water from soil leaving it dry & salty, the destruction of our forests to the plastics industries polluting our water etc etc. Technically, there is no such thing as fresh water anymore- our drinking water may now be free of disease & parasites, but it is now full of artificial hormones (from the plastic industries), chemicals and even drugs.
I totally agree with Putrefaction that we need to be doing so much more with recyling. Recyling preserves resources and reduces wastage. I forsee that perhaps in the distant future people will go back to the landfills we dig today to recycle the materials we dumped in them.
The reason why no politicion will commit to recycling on anything more than a superficial level though is the same reason why our economies are failing and that even problems almost everyone can see and see solutions too are not being fixed...These measures take time & money to put into practice, and no matter how much unlimited good putting in better practices will do in the long term, few politicions are willing to put their necks on the line for the initial work to get things going. Politicions are self-absorbed and only care about their carears. Democracy is flawed and the government is corrupted by political "sponsership".
So yes. Many people probably don't really care about how much plastic is being dumped into landfills or how many by-product chemicals are being washed into our waters (causing all manner of damage to marine ecosystems and people, which we are only just beginning to understand)- they probably care more about their job right now, their mortgage payments, their childrens education or their food or fuel budget. And they only care about politics when these things are being directly negatively affected- afterall, why spent energy worrying about someone elses problems?
But un-united we fall, and its this "its someone elses problem not mine" attitude that has allowed so much of the immoral behaviour in our governments. We no longer fight for everyone's benefit, only our own. In the big picture all these things are in one way or another way interconnected!
Support your fellow citizen if he or she has a good cause, because although it might not interest you particularly, standing together we empower ourselves and can have much more sway when our own interests are threatened! Though of course, the government would rather have everyone divided in this farce of a democracy as divided we are weaker and easier to control. We complain, but increasingly no one pays heed. The more we complain the less we do and the weaker we become.
Instead of relying on other people to solve the future's problems, why not make an effort to find solutions yourself, make an ethical/moral stand or even just make an individual effort, as then you will be a part of the solution rather than a part of the problem.