Please explain what you mean. All animals breed, are you suggesting that humans don't have the same right as all other living creatures?
What do you mean by sustainable future?
Not all animals breed. Many animals die before they can accomplish that. Human beings are very successful as a species. Modern medicine, nutrition, and lifestyles mean that people, on average, live a long time, giving everyone plenty of opportunity to breed. For example, some people theorize that bad eyesight is a recent phenonmenon. Ancestors carrying the trait would have been at a serious disadvantage. But glasses fix that.
People with genetic diseases (eyesight is a little extreme) should not be allowed to reproduce as much simply because they are able to reproduce as much. One child for the most severe of cases would be fine. If you have a dominant p53 mutation, for instance, you should be able to have only one surviving child.
Our population is growing exponentially, and the problem must be remedied fast. The world's carrying capacity cannot currently support a population of 20 billion. Like Malthus predicted a long time ago (before the agricultural revolution), we are heading for disaster once more, this time at the limits of human potential. Our minds will be tested, and it is arrogant to believe we will prevail over nature once again.
P.S. Obviously the controversial point is, "Who decides who can have how many children." But I think that some kind of legal consensus could be reached. Even fairly fit individuals should not be able to reproduce like rabbits.
The point is that it is simply irresponsible to have more children than the world can handle.
[edit: the population problem is greater in developing countries. the genetics problem is greater here. fecundity in the US is already fairly low.]