Avoid contractions such as 'doesn't'
Contractions are typical of speech and less formal writing but are best avoided in formal text.
Less formal:
(1a) This problem doesn’t have an environmentally friendly solution.
More formal:
(1b) This problem does not have an environmentally friendly solution.
(1c) This problem has no environmentally friendly solution.
In (1c), the phrase does not have an has been replaced by has no; see Strategy 7: Choose 'no', 'few' and 'little' .