“I’ve seen things you people wouldn’t believe … Attack ships on fire off the shoulder of Orion … I watched C-beams glitter in the dark near the Tannhäuser Gate. All those moments will be lost in time, like tears in rain … Time to die.”
Rutger Hauer’s character from Blade Runner, Roy Batty, closes the film with a philosophical reflection on humanity and the precious power of memory and moments. For Distinguished Professor Michael Mann, the last words of this quotation are problematic.
He is known for serious, cautious, evidence-led work, rather than a sensational ‘doomer’ approach, so Our Fragile Moment is neither dirge nor eulogy. Instead, this is an accessible, engaging book, which details how we have arrived at the “absolute fragility of this moment in time”, comparing our present day with extinction events in the past and exploring what solutions we have currently at our disposal.
Lessons from the past
The lesson from the past that Mann opens with is that every species and civilisation has its moment, but that, “Thanks to the efforts of those [fossil fuel] corporations, we’re now coming up against the boundary of habitable life for us humans”.
Mann emphasises that though climate change is a crisis, it remains a solvable one. Mann is known for scientific rigour and he is clear that uncertainty itself is no bad thing, but is part of the process that leads to greater understanding – as indeed, scientific exploration always has. He says, “We must embrace scientific uncertainty. The scientific process builds on itself. New data come to light that help us refine our understanding”.
Is it then ‘time to die’, as in the Blade Runner quotation? Mann acknowledges that this is the “big question on everybody’s mind: Are we doomed?” And although a fatalistic reader may expect a clear answer, as global temperatures continue to rise and climate events become more frequent or extreme as we inch towards 1.5°C above the pre-industrial levels, Mann is still emphatic that “it is entirely up to us”.
He repeatedly makes the point that the challenge in implementing climate action is down to political will, rather than not knowing the solutions:
“We have sophisticated technology today that we can employ in an effort to adapt to climate change …
“Most importantly, we have the technological know-how to decarbonize the global economy, moving away from the harmful burning of fossil fuels toward clean energy and climate-friendly agricultural and land use policies. The obstacles here aren’t technological. They are political.”
Beware of climate determinism
Mann charts the climate impacts that have shaped the paleoclimatic past of our planet and the devastating effects that some had on life forms present at the time, from the Permian-Triassic extinction – “an estimated ninety percent of all Permian species disappeared from the face of the planet” – to the cataclysmic event that wiped out the dinosaurs:
“From sixty-six million years ago, when our distant rodent-like ancestors crawled out from the shadows of the dinosaurs, to five million years ago, when our less-distant primate ancestors came down from the trees to hunt on ancient African savannas, climate has shaped us.”
He focuses on the impact of our human ancestors’ migration and settlement. “Our species, Homo sapiens, had finally made the transition from nomadic to sedentary existence. We had learned to cultivate food crops and raise livestock.”
Mann investigates various cultures and civilisations such as the Sumerians, Romans and Anasazi and cautions against assuming there is just one deciding factor in the decline of empires.
“Now, we must be wary of climate determinism: the notion that every significant historical event, every societal origin or collapse, can be interpreted entirely through the lens of climate change. We must always appreciate the complexities of human behavior and sociopolitical dynamics that effect societal changes.”
An over-dependence on fossil fuels
He believes humans “delved too greedily and too deep” and as a result, awakened the ‘Balrog’ of the fossil fuel industry.
“We helped create our fragile moment, a stable global climate upon which to build the infrastructure of human civilization. We should have stopped while we were ahead. But we went further. We constructed an industrial civilization that was entirely dependent on fossil fuels.”
More optimistically, he suggests that, “We also have distinct advantages over the past civilizations … because, unlike them, we have the ability to anticipate the future”.
We should see the collapse of other civilisations as cautionary tales in how to manage the inevitable mass migration that will follow.
Mann quotes Andrew Harper, an adviser to the United Nations high commissioner for refugees, who argued that “climate change is reinforcing underlying vulnerabilities and grievances that may have existed for decades, but which are now leading to people having no other choice but to move”.
The ‘known unknowns’
Switching the focus to exploring the ‘known unknowns’ of climate stability, Mann evaluates the two faces of climate – resilience and fragility. He makes the argument that knowing how far away climate ‘tipping points’ are can be difficult to predict.
“As we continue to burn fossil fuels and generate atmospheric carbon pollution, we’re pushing the planet harder and harder. The question is, how long before we’ve pushed too hard?”
Mann warns that this ‘unknown’ should give humanity pause, since pressing the ‘reset’ button on the climate later on, will not restore what has been lost. The ice sheets, once gone, will not return in human timelines and the deep-ocean circulation system won’t suddenly come back if it collapses.
“Even if we warm the planet up enough to melt the ice sheets, there’s a chance we could cool the climate back down over the next century … But it’s not as if the ice sheets will return. They’re done. It would take millions of years to bring them back …
“A similar thing holds with the great ocean conveyor. If that circulation pattern collapses due to warming and we cool the climate back down, that circulation pattern doesn’t come back.”
How risk-tolerant can we be with this one Earth?
Mann opens up a fascinating comparison of our carbon pollution behaviour now with what took place in ‘the Great Dying’ of the Permian-Triassic extinction. He argues that as our focus is usually on the catastrophic extinction levels, we sometimes forget that life finds a way and that some species both survived and thrived in their own fragile moment.
“The question on your mind won’t be, ‘Why did ninety-six percent of ocean life die off?’ It will instead be, ‘How did four percent actually survive?’”
He highlights that there were multiple factors involved in the Great Dying which we are not witnessing in today’s world and therefore it is not time to give up hope.
“The Great Dying is often pointed to as a potential analog for the consequences of current-day human-caused climate change. But it’s an imperfect one … The message here is that there is cause for concern, and a strong reason to act. But it’s certainly not a reason to give up hope for our species.”
Mann’s analysis does not neglect to mention the unquantified amount of carbon released by the numerous wildfires we have seen around the globe in 2023 and he points out that this new information and evidence needs to be factored into the discussion. The emission rate of the carbon that humans are contributing, Mann argues is seriously problematic:
“We’re adding carbon to the atmosphere a hundred times faster than the natural episode that caused the greatest extinction in planetary history.”
It is no longer a philosophical question that must be asked at this moment in humanity’s existence, but rather a practical one which reminds us of what is at stake: “How risk-tolerant are we willing to be with our one and only planetary home?”
Earth is our present and future home, and despite our searching of the stars for new habitable planets, we cannot discard the beauty and splendour of this fragile marble in space, nor push the equilibrium past a point of no return, without dire consequences for our species.

There is urgency and there is agency
Mann makes the emphatic point though that, unlike the dinosaurs, humans now have both urgency and agency with which to act and that this creates hope for extending our fragile moment in the sun.
“A better reason for optimism is this essential distinction: there was nothing the dinosaurs could have done about their plight. They had no means to deflect the asteroid. They lacked agency. We do not. We are threatened with a catastrophe of our own making. And the primary challenge we face isn’t the immutable laws of astrophysics. It’s political will.”
He convincingly argues that “our fragile moment can still be preserved”, but that this is reliant on what we choose to create.
“We cannot say what our future will be. But we can talk about what futures we are still able to create.”
The future is not black and white
As this is a carefully nuanced book, rather than one which celebrates the absolute states of black and white, I can understand why it might not be universally applauded, especially by those who look for simple, sensationalist points to generate social media engagement. Some readers seem to want the authors of new climate books to provide cut-and-dried answers and become frustrated when they are met with complexity and uncertainty.
But Mann encourages us to welcome the complex incremental moves forward in climate science knowledge, rather than to respond to every successive climate report as if it was the end of the world as we know it.
He warns against the new breed of hypersensitive social media users, for whom engagement is more important than recognising scientific uncertainty and informed debate, lamenting that, “nuanced views struggle to gain currency in a political economy where hot takes, hyperbole, and polarizing commentary best generate clicks, shares, and retweets”.
Mann is clear that this hyperbolic approach is unjustified:
“There is no need to exaggerate the threat. The facts alone justify immediate and dramatic action.”
We can be the winners or the losers
Climate projections of possible futures perhaps lack the inclusion of one factor – that of human endeavour and unity. Our science fiction stories normally have the same common factor – they portray events happening to us. Humans are the common factor and we are capable of greatness. This is our moment.
Mann indicates that in the historical record, there are always species that take advantage of changing climates and adapt faster than others and therefore survive.
“There are always winners and losers … If we extinguish ourselves, other creatures will undoubtedly exploit the niche we had filled. They’ll be the winners. And we’ll be the losers. Yes, the planet itself will continue on just fine. But without us. Our fragile moment will be over.”
It is perhaps fitting that the final words do not go to Mann, but rather to his idol and great scientific thinker of the late twentieth century, Carl Sagan. Mann opens Our Fragile Moment with this quotation from Sagan, but maybe we should be using it as a clarion call for the times yet to come:
“We are at a crossroads in human history. Never before has there been a moment so simultaneously perilous and promising. We are the first species to have taken evolution into our own hands.”