Translate the following English sentence to French:
"Finally, I want to say that I attach great importance to making a start on phasing out discharges, emissions and leaks of hazardous materials and to the fact that we can do this gradually but, at the same time, be set a target, namely the year 2020 by which time we should hopefully have reduced such emissions to zero."
J'ajouterai enfin que l'introduction de mesures d'élimination progressive des déversements, émissions et pertes de substances dangereuses constitue, selon moi, un élément capital. Nous pouvons y arriver progressivement, mais nous devons parallèlement fixer un objectif final, à savoir l'an 2020, où, j'espère, nous aurons atteint le chiffre zéro.