Pope Benedict XVI warned those mulling climate change in a U.N. conference in Bali that good science rather than fashionable notions should guide attempts to slow the heating of the planet, and that the world’s poor should not have to bear a disproportionate burden of the cost.

And in an oblique incursion into the American presidential election, Benedict stressed that those who undermine family values, such as those who divorce or who propose same-sex unions, threaten the peace of the world.

He also contributed to the debate over an issue that is exercising presidential candidates of both major parties by saying he believed that “basic health care for all” was essential to maintain family life and cause it to prosper. The Vatican released the pope’s New Year’s message three weeks early to maximize its impact upon the Bali conference on climate change. “We need to care for the environment: It has been entrusted to men and women to be protected and cultivated with responsible freedom, with the good of all as a constant guiding criterion,” the pope wrote.

“Respecting the environment means not selfishly considering nature to be at the complete disposal of our own interests, for future generations also have the right to reap its benefits.”

But that did not mean mindlessly adopting arbitrary measures to sustain the Earth’s resources. “Humanity today is rightly concerned about the ecological balance of tomorrow. It is important for assessments in this regard to be carried out prudently, in dialogue with experts and people of wisdom, uninhibited by ideological pressure to draw hasty conclusions,” he warned.

“Nor must we overlook the poor, who are excluded in many cases from the goods of creation destined for all,” he wrote. “If the protection of the environment involves costs, they should be justly distributed, taking due account of the different levels of development of various countries.”

The pope did not play down the urgency of coming to a conclusion about what needed to be done about climate change. Developed countries like America must change their wasteful ways, because “the problems looming on the horizon are complex and time is short.”

Rich countries, he wrote, are “facing two pressing needs: to reassess the high levels of consumption due to the present model of development, and to invest sufficient resources in the search for alternative sources of energy and for greater energy efficiency.”

Developing countries should not be “forced to undersell the energy resources they do possess.” Exploitation of poor countries for their energy supplies sometimes meant “their very political freedom is compromised,” which was “clearly humiliating.”

“Due account must also be taken of the moral obligation to ensure that the economy is not governed solely by the ruthless laws of instant profit, which can prove inhumane,” the pope wrote. Countries must work together to find a way to protect the environment, the pope argued. “Further international agencies may need to be established in order to confront together the stewardship of this home of ours.”

The pope made his plea for environmental fair play in the wider context of a single world family based upon millions of individual families, which were the building blocks of a just and humane society.

“The human community cannot do without the service provided by the family. Where can young people gradually learn to savor the genuine ‘taste‚’ of peace better than in the original ‘nest‚’ which nature prepares for them,” he wrote.

In a passage that is sure to discomfit those presidential candidates who preach family values but have been divorced, the pope spelled out that if the institution of the family is undermined, the peace of the world, no less, was put at risk. He went out of his way to stress that the only marriage he recognized was one between a man and a woman.

“Whoever, even unknowingly, circumvents the institution of the family undermines peace in the entire community, national and international, since he weakens what is in effect the primary agency of peace. This point merits special reflection: Everything that serves to weaken the family based on the marriage of a man and a woman constitutes an objective obstacle on the road to peace,” he wrote.

In a further indirect contribution to the American presidential debate, he stressed that to maintain the health of the family requires universal health care. “The family needs to have a home, employment, and a just recognition of the domestic activity of parents, the possibility of schooling for children, and basic health care for all,” he wrote.

Without naming Iran, the pope also hinted that the Islamist nation should not be allowed to develop nuclear weapons. “It is truly necessary for all persons of good will to come together to reach concrete agreements aimed at an effective demilitarization, especially in the area of nuclear arms,” he wrote.