ROME — Jeffrey Sachs — one of the world’s best-known economists — is also arguably one of the world’s biggest cheerleaders of Pope Francis and believes him to be the most important moral leader in the world today.

Sachs, who is not Catholic, has advised the Vatican on papal documents for over 25 years now. Despite having notable disagreements with the Church on issues such as contraception and population control, he’s accepted the call of the last three popes for people of “goodwill” to dialogue with the Church and seek common understanding.

Through his work with the Pontifical Academy of Sciences, Sachs was a critical player in helping craft Laudato si’, Francis’s 2015 encyclical calling for greater care for creation, and today he’s a leading champion of the document on the global stage.

Sachs was recently in Rome for meetings of the Pontifical Academy and spoke with Crux on the third anniversary of the encyclical’s release, which he believes remains a clarion call for change from policymakers and powerbrokers all the way down to everyday Catholics in the pews.

Crux: You’ve consulted on a number of papal documents, both under St. Pope John Paul II and now Francis. How was the process for Laudato si’ different than previous experiences?

Sachs: Each time that I’ve participated, it’s been a very serious and impressive process. In Centesimus Annus [Pope John Paul II’s 1991 encyclical on Catholic social teaching] advisory preparation they called in many economists from around the world for input and a very considered process with a long discussion with Pope John Paul II.

In the case of Laudato si’, there was an absolutely remarkable period of lead-up bringing the world’s top scientists, climatologists, engineers, as well as many other communities of engagement — politicians, judges, mayors, and others to the Vatican so that this issue could be explored in tremendous depth.

I regard the Pontifical Academy of Sciences as a unique institution in the world because it’s the cutting edge and the highest level of scientific engagement, combined with the faith of the Church. There are no counterparts that I know of with the convening power where the world’s leading experts came, made inputs, contributed, and then we all sat back and watched this beautiful encyclical emerge.

By some accounts, Laudato si’ is the most quoted papal document in history in just three years’ time. How do you account for that?

It’s magnificent — absolutely magnificent. You read it and it’s breathtaking. I often say that I can assign it to first year graduate students in earth sciences, biology, theology, diplomacy, or political science. It’s so compellingly holistic that it can be read from all these crucial points of view, so therefore it inspires in its profundity, and it speaks to our urgent needs in a very direct way. The language is also very clear, and I think it brings the full emotional response to all of the knowledge that is deeply interwoven in the document.

Pope Francis recently met with leading oil industry executives and urged them to reduce their use of fossil fuels. Do you believe they’ll take this to heart?

I think it was a very significant gathering, and I was privileged to be part of it. These were oil industry executives who have accepted the basics of climate change. They know that this is real and that they have an important measure of responsibility.

However, I don’t think that the industry is taking as a group the decisive clarity of action — the strength and urgency of action necessary in light of the science. Pope Francis spoke to them extremely directly and said you have the responsibility of the Paris Climate Agreement and a lot of that involves leaving oil and gas under the ground because if we try to take all of the oil and the gas that we economically and profitably can, we will wreck the planet. Pope Francis was very direct, and I know that in such settings everyone listens in rapt attention, so I’m sure that it has a big effect.

What’s been your experience with U.S. leaders over the past three years since the release of the encyclical — both in terms of embrace of, and resistance to, the document?

I’ve been to many university gatherings since Laudato si’ was issued, and of course, I love universities and believe they are centers of learning and knowledge, reflection and contemplation and are unique in our society. Laudato si’ has been deeply received by scholars in the United States and these are universities holding powerful meetings engaging faculties across many disciplines, engaging students, and engaging the public.

On the other hand, some time you see parts of the American Catholic community that are resistant and even misunderstanding completely the process because they say, ‘Who is the pope to speak about these issues? He’s not a climatologist.’ They seem not to be aware of the commitment of the Church to get the best knowledge and the most rigorous science in the world as preparation for a document like this. They simply seem not to be aware of how it really works and how this is a Church that is committed to scientific evidence and rigor, as well as to the morality, the ethics, and the social teachings and theology.

There are definitely parts of conservative Catholic America that have been resistant to this, but I think they really misunderstood when they glibly say ‘the pope shouldn’t get into this.’ The pope is into this, of course, because it’s at the core of our moral need, but he doesn’t do it lightly. He does it on the basis of the most careful, multi-year examination of this issue, which is thoroughly embedded in Laudato si’.

Some of your critics complain that because you’re at odds with the Church on certain issues that you shouldn’t be involved in consulting on Church documents. What’s your response to them, and in the process of being involved, are there areas where you’ve come to sympathize more with Church teaching?

I love the Church’s social teaching, and I love the leadership the Church shows in goodwill to humanity. Pope Francis has said repeatedly that his encyclicals are a call to all of humanity and they touch me very deeply. I find Pope Francis to be our greatest moral leader in the world.

When I had the profound honor to work with Pope John Paul II, I found similarly the power of this Church to promote the common good in ways that no other institution can. I came here in 1999 when Pope John Paul II was propounding the Jubilee Year and the call to debt relief. I’m one of the world’s authorities on sovereign debt crises, and what Pope John Paul II said on that occasion was not only accurate, which I’ve come to expect, but profoundly important in moving the U.S. Congress and moving international institutions.

I came here in 1991, around Centesimus Annus, and I was then Poland’s leading external economic advisor, and obviously, Pope John Paul II was deeply interested in interrogating me closely about Poland’s economic reforms that I was very involved in. Of course, this Church played a huge role in making those reforms successful in helping keep the moral spirit and the morale of the Polish people. So, when the Church calls, we listen and we find it compelling. We also respond to the profound ethics of this Church and our ears, and heads, and hearts are open.

Much of Laudato si’ is engaged in calling on broad, structural changes in our world. How would you respond to the average Catholic who says, ‘Give me a tangible way in which I can live it out practically in my own life’?

I hope that their parishes have solar panels on their roofs, and I hope that they’re speaking with their congressmen who very often take contributions from oil companies, and therefore, don’t speak about the urgency of climate change, and tell them that ‘we are your real constituency — not the oil company. You are to look after us, and we hear Pope Francis’s call and agree with it, and we want our representatives to represent the public, the common good, and future generations.’

I hope similarly that within the Church, Catholics will tell their bishops who are big voices in our nation and our world to please follow Pope Francis in his plan for our common home. Each person has a role to play in being a responsible steward of their own homes and a responsible citizen. They may be business people, they may be students, they may be academics, they may be community leaders or politicians — everybody has a role to play to pitch in for the common good, and Laudato si’ is a magnificent and inspiring guide for us.

I think people should reflect on their multiple roles in our households, as consumers, and producers, within the multiple sectors of society, to answer that question by thinking carefully what indeed they can do, what Pope Francis calls on all us to do, which is to play our role for the common good.