Havel's essay "Politics and Conscience" (link to English translation from here; I have a print copy in a book entitled Vaclav Havel: Living in Truth) was written in February 1984 as a speech to be delivered on receiving an honorary doctorate at the University of Toulouse-Le Mirail. Havel himself was prevented from travelling to Toulouse for the occasion as the Czech authorities had confiscated his passport; the text was first circulated in a samizdat publication(underground publishing) in Czechoslovakia. There are striking similarities between Havel's text and chapters three and four of Pope Francis' encyclical letter Laudato si. Compare, for example, the opening paragraph of Havel's essay (written, like the remainder of the essay, from an existentialist background):
As a boy, I lived for some time in the country and I clearly remember an experience from those days: I used to walk to school in a nearby village along a cart track through the fields and, on the way, see on the horizon a huge smokestack of some hurriedly built factory, in all likelihood in the service of war. It spewed dense brown smoke and scattered it across the sky. Each time I saw it, I had an intense sense of something profoundly wrong, of humans soiling the heavens. I have no idea whether there was something like a science of ecology in those days; if there was, I certainly knew nothing of it. Still that "soiling of the heavens" offended me spontaneously. It seemed to me that, in it, humans are guilty of something, that they destroy something important, arbitrarily disrupting the natural order of things, and that such things cannot go unpunished. To be sure, my revulsion was largely aesthetic; I knew nothing then of the noxious emissions which would one day devastate our forests, exterminate game, and endanger the health of people.and n.115 of Pope Francis' encyclical (the quotations are respectively from Romano Guardini and Pope John Paul II):
Modern anthropocentrism has paradoxically ended up prizing technical thought over reality, since “the technological mind sees nature as an insensate order, as a cold body of facts, as a mere ‘given’, as an object of utility, as raw material to be hammered into useful shape; it views the cosmos similarly as a mere ‘space’ into which objects can be thrown with complete indifference”. The intrinsic dignity of the world is thus compromised. When human beings fail to find their true place in this world, they misunderstand themselves and end up acting against themselves: “Not only has God given the earth to man, who must use it with respect for the original good purpose for which it was given, but, man too is God’s gift to man. He must therefore respect the natural and moral structure with which he has been endowed”.Both Havel and Pope Francis address the place of technology, and the dominance of what Pope Francis terms a "technological paradigm", not only in its impact on the natural world but also in its impact on how persons live in society, on economic and political life. Both argue against a "depersonalised" (Havel's word) exercise of political power, driven by technology, ideology, consumerism etc, and in favour of a resumption on the part of the individual person of their own responsibility towards the world around them and towards their neighbours. Both warn that solutions that are merely technological in nature will not suffice, and that solutions need to be sought that will reform the way in which people live. What Havel terms "anti-political politics" (cf the last paragraph of section IV, but you need to read the two preceding paragraphs to fully grasp this idea) has an affinity to what Pope Francis terms "the common good" (Laudato sinn.156-158).
Interestingly, in his essay Havel can refer to "science as displacing God and taking over his throne", though one should not thereby infer a religious belief on his part. Rather, if the essay is seen in its whole, Havel is recognising that there is something transcendent, and deserving of respect, in the world in which we live; and something in the human person that seeks to recognise and live in harmony with that transcendence. Pope Francis, of course, can situate this within an explicit teaching on the world as created by God.
Pope Francis, in Laudato si, sought to approach the question from the point of view of offering a teaching about mankind's relationship to the natural world in which we live. Havel, though he opens his essay by considering the ecological question, primarily seeks to offer a warning to Western European nations about the depersonalized and dehumanizing exercise of power to which he was subject under a Communist regime but which he saw in their nations under the guise of technology, consumerism and a politics of system and bureaucracy. From different directions, they approach the same question, the question that, since the publication of Laudato si, might be termed the question of an "integral ecology"; though the different directions of approach and their different immediate contexts also explain the treatment of different specific questions, particularly in Laudato si
To fully appreciate the proximity of the thought expressed in Havel's essay to that in chapters three and four of Laudato si, I think you have to read the full texts themselves .....