Fear of climate change is only natural, and it is perhaps inevitable that some people take refuge in denial. One father I met in San Francisco, a city proud of its green consciousness, told me that he deliberately avoided news about climate change – it was too depressing… “I think people my age will be alright,” he said. “Things will be tolerable for the next twenty years or so. But our kids are screwed.”

The twisting tug of alternate strategies for dealing with the not-so-slow motion catastrophe that seems ready to engulf human civilization is one that threads through Mark Hertsgaard’s lively, surprisingly hopeful treatise but is never quite resolved. That is as it should be, and not just because the proponents of each camp have such potent arguments in their favor. This is also due to the fact that climate change has advanced to such an alarmingly dangerous state that we as a race no longer have the luxury of choosing between strategies – we’re going to have to use all of them, and hope that it will work.

Much in the same way that the American reading public tuned out stories of the wars in Afghanistan and Iraq after a couple years, no matter what the status of the conflict (those IEDs just keep coming), so too readers have now seem to go glaze-eyed when the subject turns to climate change. Perhaps this is as a result of the message’s tendency to get darker and more severe with each passing season. No matter how doom-saturated Al Gore’s Earth in the Balance and An Inconvenient Truth may have been, they seemed to hold out the hope that once people really woke up to the issue. Preferably, the nations of the world would figure out that pumping billions of tons of pollutants into the air and water was going to irreparably damage our environment, and would then do something about it.

This is the mitigation argument, which says that we can still, by cutting emissions and changing our way of life, curb climate change to such an extent that we will be able to escape its worst side effects. Its proponents have long pushed for optimism in their message, fearing that overuse of scare tactics – or even just worst-case scenario forecasting of factual data, as Hertsgaard points out – would make people so frightened they would duck their heads in the sand, much like the father quoted above.

What Hot, in its somewhat circuitous manner, makes clear is that, much like how long-honed military strategies can be made irrelevant in seconds by a clever enemy, the mitigation side’s point has been overtaken by facts on the ground. In other words, it’s too late to completely stem the tide of climate change, no matter what we do. Hertsgaard quotes one alarming study that purports to show that even if the developed world slashed its emissions to nothing, climate change would still occur.

What has happened, Hertsgaard reports, is that scientists are learning more about how things like melting polar ice, warming seas, and a hotter atmosphere can create vicious “positive feedback” loops that, once started, become almost impossible to stop. In this situation, then, mitigation remains an incredibly crucial point in ensuring humanity’s survival in the coming years, but adaptation to the change that can’t be stopped becomes just as important.

In toggling back and forth between the mitigation and adaptation sides, Hertsgaard sometimes loses sight of his central thesis, namely, his daughter Chiara, who he wrote this book for. Hertsgaard’s mission was to investigate what the world was going to look like in the coming decades that Chiara was going to have to live through. To say that it’s a frequently disheartening report that he brought back is a staggering understatement, and not just because of the gargantuan human folly involved.

Much like Peter Ward’s The Flooded Earth: Our Future in a World Without Ice Caps (Basic Books, 2010), Hertsgaard cuts through much of the chaff around climate change by simply stating the facts: sea levels have already risen by about a foot in the last century, and in the next they will definitely rise several more. Because of that irreversible fact, untold millions of people are going to be displaced into a world where – because of other climate-change stressors on water supply and agriculture – their survival will be in danger. This is a harrowing truth, and one that hasn’t been done any favors by what Hertsgaard called “the lost decade” of George W. Bush’s time in office (which followed the similarly wasted Clinton-Gore years), when the world’s greatest polluter turned its back on science, “thereby leaving the door open for China and other nations to continue increasing their own emissions.” Because of this, Hertsgaard writes, our future scenarios range from the tough and unpleasant but manageable to apocalyptic; there are no good options left:

When I think about Chiara confronting a world like the one described in the UK Met Office’s study of a 4ºC temperature rise – snowpacks gone, the Amazon burning, sea levels soaring – well, I can’t think about it for long. It’s too depressing. I said earlier in the book that denial isn’t much of a survival strategy, and I still believe it, but I confess I sometimes see its attractions.

Hertsgaard is a worrier but ultimately a hopeful one. A realistic pessimist, he is intent on delivering the news that people are going to need to hear about their future, whether they want to or not. The seas will rise, temperatures will soar, storms will come faster and more frequently, and there is no single action or invention that will turn this around. Of the many “silver bullet”-styled techno cures (like using biochar, or charcoal, to remove CO2 from the atmosphere) that attract the attention of many climate scientists and bubbly pro-tech cheerleaders like Bjorn Lomborg, none will be able to magically deliver humanity from the abyss. “But,” Hertsgaard writes, “they may be pieces of silver buckshot.”

While this can seem a depressing point of view at first, it is ultimately hopeful, showing a belief that humanity will be able to come up with many, many pieces of buckshot to protect itself from the dangers already unleashed. The message from the many wise and dedicated people whom Hertsgaard talked to for this book can be summed up by what he calls the “cardinal rule” of the Dutch planners who (being that their below-sea-level country is more at risk than many) are building contingencies for the next two centuries: “Begin now: you have farther to go than you think.”