I was admitted to one University and the oath University wanted to be filled by all the alumni and students included a sentence about switching off lights when not in use. I pondered a lot how switching off lights can reduce green house gases. One ad of a blue chip company in India says reduce use of paper and save trees.  News print is made of plants or plant residues.
I appreciate two time use of envelopes in some Universities - The envelopes that University receives are used again to send internal post. Saving of paper and saving environmental destruction. If we are using less luxurious life taking pains to switch off lights, Newspaper owner become to the point and less advertisement minded at least in India once the coloured pages have started coming in news papers major portion of the news paper is taken away by ads in colour - remember colours are harmful to health. Using a smaller tank for toilet flush  even by one litre could save billions of litre of water across the globe.
If we wish to maintain present level of increase of population in developing world - for obvious reasons and ever increasing luxurious life style of living and education - now many upcoming universities in India and Schools and Colleges have huge areas of several hundred ha as lawns for the happiness of a few while adjacent villagers face decreasing water tables  and crops start drying. Mafias control mining - that was the news item some 10 -20 years ago not today.

Message is simple and clear  in all our efforts to save energy use and optimisation of water on the global earth we are only ensuring a better future for our children to come tomorrow. The question is who wants to have children in rich and affluence societies at least their populations are not increasing as fast as in the developing world after all population growth is also index of some achievement. Only environment is sufferer and so are we.