The encyclical letter Laudato Si is available here on the Vatican website.
The term “climate change” covers many possibilities: warming of climate, changes in geography and precipitation and agricultural patterns, as well as possible tipping points where climate conditions yank back into unpredictable and very short-term changes. It is, as Pope Francis describes, a worldwide issue:
25. Climate change is a global problem with grave implications: environmental, social, economic, political and for the distribution of goods. It represents one of the principal challenges facing humanity in our day. Its worst impact will probably be felt by developing countries in coming decades. Many of the poor live in areas particularly affected by phenomena related to warming, and their means of subsistence are largely dependent on natural reserves and ecosystemic services such as agriculture, fishing and forestry. They have no other financial activities or resources which can enable them to adapt to climate change or to face natural disasters, and their access to social services and protection is very limited.
The wealthy will be able to afford beachfront property in the Canadian, Alaskan, or Russian Arctic.
For example, changes in climate, to which animals and plants cannot adapt, lead them to migrate; this in turn affects the livelihood of the poor, who are then forced to leave their homes, with great uncertainty for their future and that of their children.
One issue missed by many scoffers is that human damage to the environment has already put tens of millions on the road, trying to rebuild their personal economies:
There has been a tragic rise in the number of migrants seeking to flee from the growing poverty caused by environmental degradation. They are not recognized by international conventions as refugees; they bear the loss of the lives they have left behind, without enjoying any legal protection whatsoever. Sadly, there is widespread indifference to such suffering, which is even now taking place throughout our world. Our lack of response to these tragedies involving our brothers and sisters points to the loss of that sense of responsibility for our fellow men and women upon which all civil society is founded.
This, my friends, is the definition of civilization. It separates us from those who would abandon or ignore the neediest among us.