“Everything is connected,” wrote Pope Francis in his 2015 encyclical Laudato Si’, a document much praised for its insights on the environment, although it offers much more than that. It blends an examination of climate change with a dissection of the ethical and moral failings of humankind to argue convincingly that spiritual decline and environmental destruction are two parts of a single crisis.

Pope Francis addressed Laudato Si’ to all the world, not just to Catholics, which made it unique among more than a century of papal encyclicals. But as we mark the fifth anniversary of this seminal document, it is clear 2015 will be known as the year the Catholic Church moved boldly from the periphery of the environmental movement into the centre — or even perhaps into a leading role.

The Pope wrote persuasively about an integral ecology in which the relationship between the environment and humanity is intimately interconnected to the planet’s social, political, economic and cultural structures.

Smokestacks may pollute the air, but they are fuelled by human choices. When those choices are founded on greed or consumerism, rather than the common good, the nuanced relationship with the ecology breaks down.

To avert a climate catastrophe, wrote the Pope, society must reverse its ethical and moral decline. This means rejecting arrogance, individualism and consumerism in favour of a new sensibility founded on a genuine commitment to our common home with a particular focus on the poor.

More than clean air and water, he called for a “bold cultural revolution” led by a social and moral awakening that exchanges selfish and wasteful behaviours for ethical and spiritual ones that honour creation.

Laudato Si’ has impacted ecological thinking beyond Catholic circles, but the document is every bit Catholic. Its denunciation of self-serving business and political elites goes too far for some, but its thesis is true to social-justice teachings of the Church dating back more than a century.

It declares that the environment is a Catholic issue. Further, the Pope has imbedded the Church into the defining social issue of our times by penning the defining document on the topic. Remarkably, it is a Catholic essay that even an atheist can love.

Yes, there remains a long way to go. But Laudato Si’ has inspired thousands of Catholics and others around the world to heed the Pope’s call to remake the planet into a common home that is less polluted because it is more just.

Just five years on, it seems safe to predict Laudato Si’ will be a centrepiece of the Pope Francis legacy.