The pope's encyclical, "Caritas in veritate," was published yesterday. You can find it at http://www.vatican.va/holy_father/benedict_xvi/encyclicals/documents/hf_ben-xvi_enc_20090629_caritas-in-veritate_en.html

I could not find any explicit references to Sunday, but the following quotes were interesting.

37. ...

In the global era, the economy is influenced by competitive models tied to cultures that differ greatly among themselves. The different forms of economic enterprise to which they give rise find their main point of encounter in commutative justice. Economic life undoubtedly requires contracts, in order to regulate relations of exchange between goods of equivalent value. But it also needs just laws and forms of redistribution governed by politics, and what is more, it needs works redolent of the spirit of gift. ...

41. ...

... The State does not need to have identical characteristics everywhere: the support aimed at strengthening weak constitutional systems can easily be accompanied by the development of other political players, of a cultural, social, territorial or religious nature, alongside the State. ...

62. ... Another aspect of integral human development that is worthy of attention is the phenomenon of migration. This is a striking phenomenon because of the sheer numbers of people involved, the social, economic, political, cultural and religious problems it raises, and the dramatic challenges it poses to nations and the international community. We can say that we are facing a social phenomenon of epoch-making proportions that requires bold, forward-looking policies of international cooperation if it is to be handled effectively. Such policies should set out from close collaboration between the migrants' countries of origin and their countries of destination; it should be accompanied by adequate international norms able to coordinate different legislative systems with a view to safeguarding the needs and rights of individual migrants and their families, and at the same time, those of the host countries. ...

67. In the face of the unrelenting growth of global interdependence, there is a strongly felt need, even in the midst of a global recession, for a reform of the United Nations Organization, and likewise of economic institutions and international finance, so that the concept of the family of nations can acquire real teeth. One also senses the urgent need to find innovative ways of implementing the principle of the responsibility to protect[146] and of giving poorer nations an effective voice in shared decision-making. This seems necessary in order to arrive at a political, juridical and economic order which can increase and give direction to international cooperation for the development of all peoples in solidarity. To manage the global economy; to revive economies hit by the crisis; to avoid any deterioration of the present crisis and the greater imbalances that would result; to bring about integral and timely disarmament, food security and peace; to guarantee the protection of the environment and to regulate migration: for all this, there is urgent need of a true world political authority, as my predecessor Blessed John XXIII indicated some years ago. Such an authority would need to be regulated by law, to observe consistently the principles of subsidiarity and solidarity, to seek to establish the common good[147], and to make a commitment to securing authentic integral human development inspired by the values of charity in truth. Furthermore, such an authority would need to be universally recognized and to be vested with the effective power to ensure security for all, regard for justice, and respect for rights[148]. Obviously it would have to have the authority to ensure compliance with its decisions from all parties, and also with the coordinated measures adopted in various international forums. Without this, despite the great progress accomplished in various sectors, international law would risk being conditioned by the balance of power among the strongest nations. The integral development of peoples and international cooperation require the establishment of a greater degree of international ordering, marked by subsidiarity, for the management of globalization[149]. They also require the construction of a social order that at last conforms to the moral order, to the interconnection between moral and social spheres, and to the link between politics and the economic and civil spheres, as envisaged by the Charter of the United Nations.

I recall the SoP speaking of the earth's highest authority decreeing something in the end, but can't find the quote at the moment. Anyone remember such?

If the UN were reformed along the lines proposed above, the language above would allow for the universal enforcement of Sunday rest.