What’s the best way any given individual can take action to mitigate climate change? Recycle? Drive an electric car? Buy energy efficient appliances? Insulate and use less heating and cooling? Stop flying? Buy organic and local? Use public transportation? Pee in the shower and turn off the faucet while brushing teeth?

Eco-virtuous as all those actions may be, their net effect, even multiplied across the many billions of people living with the resources to make those choices, would be virtually nil compared to the one choice that would truly make a difference if taken collectively by a majority of inhabitants of the Earth: not having a child (interested in reading more about this? Try here and here).

But what does it mean, for an average couple, to take the planet under consideration in their family planning?

That’s pretty much the premise from which Duncan Macmillan’s extraordinarily smart and timely play Lungs takes off. A young-ish couple has reached that point in their relationship when baby-making is in the cards. But these two – a nameless man and woman – are the kind of high-information, self-reflective people who want to do what’s rational, right, and moral, even as they feel the irrational urge to do what generations of humans before them have done without much reflection at all. She (played by Sarah Silk) is a Ph.D. student, an overthinker and overanalyzer who is initially thrown completely off balance by her boyfriend’s suggestion that they even discuss the possibility of having a baby together, and almost immediately brings up the ecological implications: “they say if you really care about the planet then don’t have children.” He (played by Alec Silberblatt) shares her concerns, but also sees a responsibility for “good people” like themselves to reproduce, lest the genes of responsible and caring persons like themselves not survive. Their (often quite absurdly funny) back-and-forth on the decision touches on many of the arguments and rationalizations that are brought forth whenever people think about their individual actions in the face of the enormous problem of climate change – like, for example, the argument that if the only people who stop reproducing are the altruistic ones, then the world will fill with selfish people, or the argument that not having a child might mean not bringing into the world the genius who could invent a technical solution to the problem.

Off The Wall/Carnegie Stage presents "Lungs"

L to R: Alec Silberblatt & Sarah Silk. Photo by Heather Mull, courtesy Off the Wall Productions

What’s brilliant about this play is the way it puts our human tendency to rationalize and justify decisions on display and opens that tendency to both sympathy and scrutiny. As “He” puts it: “everyone thinks they’re doing the right thing.” At the same time, the play vividly makes clear that our current ecological predicament is a direct consequence of that tendency to rationalize. Multiply the kinds of individual justifications we see the man and woman making by 10 billion (the projected population in 2050), and you have a planet that will no longer be able to sustain human life.

Lungs is not only or even mostly about climate change, however – at its core, it’s a play about the relationship between the man and the woman, and about how they miscommunicate and misread each other and yet still find what they need in each other. Macmillan’s portrait of the couple feels honest and fresh, and his dialogue is sharp and often surprising. His play is also unconventionally challenging to stage: he specifies that it should be played on a completely bare stage, with no lighting or sound cues to indicate scene transitions, and although the action shifts forward in time and takes place in several locales, the script gives no clear indication where and when those shifts occur. The Off the Wall production cheats on the “bare stage” parameter a tiny bit: Adrienne Fischer’s set is a pair of oval platforms covered in bright green shag carpet, which is bordered by a set of fluorescent lights canopying like the branches of a tree over the playing space. But otherwise the play is presented in accordance with the playwright’s insructions, without furniture, props, or mime. Rising magnificently to those challenges, director Spencer Whale does a beautiful job of choreographing the action to tell the story with precision and lucidity.

This kind of spare storytelling is a gift to talented actors, and Silberblatt and Silk are superb beyond description as the man and woman. These may, in fact, be two of the finest performances I’ve seen in Pittsburgh this year – and if you didn’t make it out to Carnegie to see this play, you missed out on a highlight of 2016 (although you still have time, if you don’t have plans for tonight!!). Not only do Silk and Silberblatt bring the relationship between the man and woman into crystal clear focus and flesh out their characters’ needs and vulnerabilities with empathy, sensitivity, and wit, but they also give us two people to whom those of us who like to think we are “doing right” (and isn’t that all of us?) can utterly relate. In so doing, they give us pause to consider all the ways in which our own individual actions – as justifiable and rationalizable as they may be – will collectively bequeath the children we can’t seem to stop having a world they won’t want – or be able – to live in.