1) Central co2 laboratory, sio 2) Half of d 3) II into D 4) One quarter of M 5) One-sixth of MD 6) Quarter M 7) Quarter millennium 8) Quarter of a mille 9) Quarter of m 10) Quarter-millennium 11) Roman 250 12) Third-century year 13) When doubled, D 14) Xxv x x Found on https://www.crosswordclues.com/clue/ccl
Climate Change Levy - this Levy is charged on industrial and commercial use of energy and is one of the Government's tools for reducing emissions of greenhouse gases.
Found on http://www.encyclo.co.uk/local/20715