Another option is using a package system that properly handles dependencies. http://www.nixos.org/, for example, allows multiple Perl versions, multiple CPAN trees - and even within CPAN different module dependencies. That makes for predictable deployment, and can help development too when testing diffferent CPAN dependencies. Interestingly Nix can be used inside Debian. I have it on all my systems to test different setups. Way to go Nix! There is also an article on linux.com.

It takes 10-20 years to build nuclear power plants. Do the math. Also wind power and solar will in no forseeable future replace our current need for power. Leave alone the growing need. You missed two points of my short message: (1) we need to reduce consumption and (2) even after solving CO2 there will be other problems. The whole thing is caused by a growing population combined with unsustainable consumption. Indeed, an unpopular message.