If fertility remains at current levels, the population would reach the absurd figure of 296 billion in just 150 years. Even if it drops to 2.5 children per woman and then stopped falling, the population would still reach 28 billion. Current UN mid-range projections assume that women in the developing world will soon average two children apiece -- the rate at which population growth stabilizes and the global population reaches a maximum of 10 to 11 billion towards the end of the next century, up from just under six billion at the end of the present century.
The total fertility rate TFR) is the number of children that would be born to a woman if she were to live to the end of her childbearing years and bear children at each age in accordance with prevailing age-specific fertility rates. Many governments have programmes to reduce the fertility rate by encouraging the use of family planning through offering subsidized information and health care. Family planning ranges from indirect methods such as economic incentives and improved women's literacy to direct methods through use of contraceptives, sterilization and abortion.
From 1965-1970 to 1980-1985 fertility in poor countries dropped 30 percent, from a TFR of 6.0 to one of 4.2. In that period the poor countries of the world moved almost halfway to a TFR of 2.1: replacement level. It had fallen to 3.5 by 1994 -- almost two-thirds of the way. If the decrease continues, it will be the most astonishing demographic shift in history. (The second most astonishing will be the rise that preceded it.)< if this trend continues we will arrive at replacement level in the subsequent twenty years -- that is, by 2005.
2. Reducing population growth through positive, voluntary means is intended to help avert Malthusian means of population control such as starvation, war and epidemics. On the family level, more resources are available for each child and women have greater opportunity to contribute to family and community life.
3. Many are the means towards this end which need to be developed with skill and serious commitment. At the first stage of life, centres for natural methods of regulating fertility should be promoted as a valuable help to responsible parenthood, in which all individuals, and in the first place the child, are recognized and respected in their own right, and where every decision is guided by the ideal of the sincere gift of self. (Papal Encyclical, Evangelium Vitae, 25 March 1995).
2. Let it be considered also that a dangerous weapon would thus be placed in the hands of those public authorities who take no heed of moral exigencies. Who could blame a government for applying to the solution of the problems of the community those means acknowledged to be licit for married couples in the solution of a family problem? Who will stop rulers from favouring, from even imposing upon their peoples, if they were to consider it necessary, the method of contraception which they judge to be most efficacious? In such a way men, wishing to avoid individual, family, or social difficulties encountered in the observance of the divine law, would reach the point of placing at the mercy of the intervention of public authorities the most personal and most reserved sector of conjugal intimacy.
Consequently, if the mission of generating life is not to be exposed to the arbitrary will of men, one must necessarily recognize insurmountable limits to the possibility of man's domination over his own body and its functions; limits which no man, whether a private individual or one invested with authority, may licitly surpass. And such limits cannot be determined otherwise than by the respect due to the integrity of the human organism and its functions, according to the principles recalled earlier, and also according to the correct understanding of the 'principle of totality' illustrated by our predecessor Pope Pius XII.
The teaching of the Church on the regulation of birth, which promulgates the divine law, will easily appear to many to be difficult or even impossible of actuation. And indeed, like all great beneficent realities, it demands serious engagement and much effort, individual, family and social effort. More than that, it would not be practicable without the help of God, who upholds and strengthens the good will of men. Yet, to anyone who reflects well, it cannot but be clear that such efforts ennoble man and are beneficial to the human community.
The honest practice of regulation of birth demands first of all that husband and wife acquire and possess solid convictions concerning the true values of life and of the family, and that they tend towards securing perfect self-mastery. To dominate instinct by means of one's reason and free will undoubtedly requires ascetical practices, so that the affective manifestations of conjugal life may observe the correct order, in particular with regard to the observance of periodic continence. Yet this discipline which is proper to the purity of married couples, far from harming conjugal love, rather confers on it a higher human value. It demands continual effort yet, thanks to its beneficent influence, husband and wife fully develop their personalities, being enriched with spiritual values. Such discipline bestows upon family life fruits of serenity and peace, and facilitates the solution of other problems; it favours attention for one's partner, helps both parties to drive out selfishness, the enemy of true love; and deepens their sense of responsibility. By its means, parents acquire the capacity of having a deeper and more efficacious influence in the education of their offspring; little children and youths grow up with a just appraisal of human values, and in the serene and harmonious development of their spiritual and sensitive faculties.
To Rulers, who are those principally responsible for the common good, and who can do so much to safeguard moral customs, we say: Do not allow the morality of your peoples to be degraded; do not permit that by legal means practices contrary to the natural and divine law be introduced into that fundamental cell, the family. Quite other is the way in which public authorities can and must contribute to the solution of the demographic problem: namely, the way of a provident policy for the family, of a wise education of peoples in respect of moral law and the liberty of citizens. We are well aware of the serious difficulties experienced by public authorities in this regard, especially in the developing countries. To their legitimate preoccupations we devoted our encyclical letter Populorum Progressio. But with our predecessor Pope John XXIII, we repeat: no solution to these difficulties is acceptable which does violence to man's essential dignity and is based only on an utterly materialistic conception of man himself and of his life. The only possible solution to this question is one which envisages the social and economic progress both of individuals and of the whole of human society, and which respects and promotes true human values. Neither can one, without grave injustice, consider divine providence to be responsible for what depends, instead, on a lack of wisdom in government, on an insufficient sense of social justice, on selfish monopolization, or again on blameworthy indolence in confronting the efforts and the sacrifices necessary to ensure the raising of living standards of a people and of all its sons. (Papal Encyclical, [Humanae Vitae]: On the regulation of birth, 25 July 1968).