Are societies capable of sacrificing time and energy exclusively for the benefit of future generations?
Short answer
Yes  

Background
Consider the following organizations solely acting for preservation:


WWF for example attempts to conserve Wildlife and Marine Parks
UNESCO protects cultural properties


One way they do this is by outreach to local communities and educate them on the value of stretches of land. For example see 


How the local (poor) community fishermen are approached to save the vaquita (Nicholls, 2017)  (in an admittedly futile attempt, as there are about 14 left)
Sustainable coffee and cacao production by local farmers in the sensitive Amazone Bassin


So yes, I don't know if this is what you're after, but of course communities can be put to work for the greater cause. 

Further, as others have pointed out, this is borderline ontopic here imo, but it is an interesting and hot issue nonetheless.  

Reference
-  Nicholls, Sci Am, April 2017)