The encyclical letter Laudato Si is available here on the Vatican website. Here we begin a five-section examination on the theme of “Civic and Political Love.” Let’s read:
228. Care for nature is part of a lifestyle which includes the capacity for living together and communion. Jesus reminded us that we have God as our common Father and that this makes us brothers and sisters. Fraternal love can only be gratuitous; it can never be a means of repaying others for what they have done or will do for us. That is why it is possible to love our enemies. This same gratuitousness inspires us to love and accept the wind, the sun and the clouds, even though we cannot control them. In this sense, we can speak of a “universal fraternity”.
Love of others is rooted in a common family orientation with other people who are all claimed by the Father as his children. So it is like family: we cannot choose whom we will love.