Pope's message is clear: the poor have the greatest stake in climate talks
Pope Francis' encyclical on climate change is the Vatican's most controversial since Pope Paul VI's 1968 document, Humanae Vitae, enshrined the Catholic Church's ban on the use of contraception by its followers. What also sets it apart is that it is not teaching for Catholics on a matter of conscience, but directed at everyone as cohabitants of our "common home" with shared responsibility for it.
It is therefore worldly rather than spiritual. But this left no room for debate about the science of climate change. The pope made his stance clear and enshrined it with the church's ministry for the poor. In accepting that most greenhouse gas emissions are man-made, he spared hardly any area of society of blame, citing worship of technology, compulsive consumerism and addiction to fossil fuels as examples of reckless behaviour that have stressed the planet.
The pope's embrace of the issue of climate change and his criticism of capitalism reflect his signature economic concern - eradicating poverty. He referred to the relationship between the poor and the fragility of the planet, adding: "Both experience and research show that the gravest effects of all attacks on the environment are suffered by the poorest." Elevating it to a moral issue, he called on rich nations to begin paying their "social debt" to the poor and shoulder the economic burden of cutting emissions, an issue that has blocked progress in global climate change negotiations for years.
Francis has courted criticism by condemning the trading of carbon emissions credits because it "creates new forms of financial speculation" without effecting radical change, even though it has been widely adopted to cut carbon pollution while sustaining economic growth. Some commentators have questioned his attack on science and technology, given that they are tools that offer a solution to climate change. But no one can accuse him of failing to give a voice to the world's weak and poor at a climate summit in Paris later this year to try to strike a new deal to cut emissions.