This was said half in jest I suspect, but it's not a completely off the wall concern. For an infrequently used program the energy burned in its development could easily be a nontrivial amount of the total energy used over its lifetime. If you can write a 5 line Perl script that gets the job done (and is only run a couple dozen times ever), then you're probably saving energy over the 100 line C program despite the massive differences in runtime energy consumption.
