Save our planet, make Greta Happy, use Lisp.
+--------------+------+--------------+------+--------------+------+
| |Energy| |Time | |Mb |
+--------------+------+--------------+------+--------------+------+
|(c) C |1.00 |(c) C |1.00 |(c) Pascal |1.00 |
+--------------+------+--------------+------+--------------+------+
|(c) Rust |1.03 |(c) Rust |1.04 |(c) Go |1.05 |
+--------------+------+--------------+------+--------------+------+
|(c) C++ |1.34 |(c) C++ |1.56 |(c) C |1.17 |
+--------------+------+--------------+------+--------------+------+
|(c) Ada |1.70 |(c) Ada |1.85 |(c) Fortran |1.24 |
+--------------+------+--------------+------+--------------+------+
|(v) Java |1.98 |(v) Java |1.89 |(c) C++ |1.34 |
+--------------+------+--------------+------+--------------+------+
|(c) Pascal |2.14 |(c) Chapel |2.14 |(c) Ada |1.47 |
+--------------+------+--------------+------+--------------+------+
|(c) Chapel |2.18 |(c) Go |2.83 |(c) Rust |1.54 |
+--------------+------+--------------+------+--------------+------+
|(v) Lisp |2.27 |(c) Pascal |3.02 |(v) Lisp |1.92 |
+--------------+------+--------------+------+--------------+------+
|(c) Ocaml |2.40 |(c) Ocaml |3.09 |(c) Haskell |2.45 |
+--------------+------+--------------+------+--------------+------+
|(c) Fortran |2.52 |(v) C# |3.14 |(i) PHP |2.57 |
+--------------+------+--------------+------+--------------+------+
|(c) Swift |2.79 |(v) Lisp |3.40 |(c) Swift |2.71 |
+--------------+------+--------------+------+--------------+------+
|(c) Haskell |3.10 |(c) Haskell |3.55 |(i) Python |2.80 |
+--------------+------+--------------+------+--------------+------+
|(v) C# |3.14 |(c) Swift |4.20 |(c) Ocaml |2.82 |
+--------------+------+--------------+------+--------------+------+
|(c) Go |3.23 |(c) Fortran |4.20 |(v) C# |2.85 |
+--------------+------+--------------+------+--------------+------+
|(i) Dart |3.83 |(v) F# |6.30 |(i) Hack |3.34 |
+--------------+------+--------------+------+--------------+------+
|(v) F# |4.13 |(i) JavaScript|6.52 |(v) Racket |3.52 |
+--------------+------+--------------+------+--------------+------+
|(i) JavaScript|4.45 |(i) Dart |6.67 |(i) Ruby |3.97 |
+--------------+------+--------------+------+--------------+------+
|(v) Racket |7.91 |(v) Racket |11.27 |(c) Chapel |4.00 |
+--------------+------+--------------+------+--------------+------+
|(i) TypeScript|21.50 |(i) Hack |26.99 |(v) F# |4.25 |
+--------------+------+--------------+------+--------------+------+
|(i) Hack |24.02 |(i) PHP |27.64 |(i) JavaScript|4.59 |
+--------------+------+--------------+------+--------------+------+
|(i) PHP |29.30 |(v) Erlang |36.71 |(i) TypeScript|4.69 |
+--------------+------+--------------+------+--------------+------+
|(v) Erlang |42.23 |(i) Jruby |43.44 |(v) Java |6.01 |
+--------------+------+--------------+------+--------------+------+
|(i) Lua |45.98 |(i) TypeScript|46.20 |(i) Perl |6.62 |
+--------------+------+--------------+------+--------------+------+
|(i) Jruby |46.54 |(i) Ruby |59.34 |(i) Lua |6.72 |
+--------------+------+--------------+------+--------------+------+
|(i) Ruby |69.91 |(i) Perl |65.79 |(v) Erlang |7.20 |
+--------------+------+--------------+------+--------------+------+
|(i) Python |75.88 |(i) Python |71.90 |(i) Dart |8.64 |
+--------------+------+--------------+------+--------------+------+
|(i) Perl |79.58 |(i) Lua |82.91 |(i) Jruby |19.84 |
+--------------+------+--------------+------+--------------+------+
source: https://greenlab.di.uminho.pt/wp-content/uploads/2017/10/sleFinal.pdf