Some years back, my wife received the news that absolutely no one ever wants to hear. We were seated beside each other in front of her doctor’s desk as he told us the tests she’d undergone confirmed that she did, indeed, have Cancer.
In that instant, every item on our life’s to-do list faded to insignificance. The scourge of Cancer immediately leapt to number one on our life-agenda. We were, in a word, gobsmacked.
Over the next few weeks, we dragged ourselves through the same range of emotions so many other people have experienced, I’m sure—disbelief, anger, denial, terror, uncertainty, guilt, anxiety. And then gradually, resolve, hope, and action.

A few years later, I received the same grim diagnosis, from a different doctor this time, but with the same gamut of emotions tumbling out in the wake of the news. And with the same re-ordering of life’s priorities. I suspect anyone who has received such a shock has experienced a similar phenomenon—every other issue of importance in one’s life comes to a jarring halt, at least for a time.
In both our situations, the Cancer had been growing inside our bodies for some while before we ever became aware of its presence. And it had continued to grow during the time it took us to obtain medical advice, to undergo tests, and to receive the results back. Our initial diffidence and slowness to act were based on a purely human trait, a perhaps-understandable reluctance to admit, even to ourselves, that something might be amiss, that something might disrupt the normalcy of our lives.
But Cancer, we discovered, is constrained by no such hesitancy. It exists insidiously, mindlessly, remorselessly, bound by no laws except its own biological imperative to metastasize, to survive. As with viruses, Cancer has no regard for our human concerns. It has no mercy.
As I write this, both my wife and I have outdueled the scourge, at least for now. But the possibility of recurrence is ever in our minds, even as our own innate optimism buoys us. It fooled us once, but we are more vigilant now, and readier to act more quickly if the need arises.
Once bitten, as the old saw has it, twice shy.

But our personal experience reminds me, unhappily, of the situation in which we, as a species inhabiting this planet Earth, presently find ourselves. For some time, a looming catastrophe has been growing, a sort of Cancer very few of us seem ready to acknowledge. We are perhaps so wrapped-up with the management of other crises and issues of importance—pandemic disease, pollution and environmental degradation, malnourishment and hunger, government corruption and a rise in authoritarianism, regional wars, terrorism, substance abuse, domestic violence, to name a few—that we are unable to pause to re-order our priorities.
But like all other Cancers, this one will prove indifferent to our ignoring of its presence. It will dwarf our other concerns, smother them, render them insignificant in the big picture, and will leap to the fore as humankind’s number one agenda-item. It will continue to grow exponentially until such time as we resolve to take immediate, aggressive, and effective action to curtail it. And by then—perhaps already—it may be too late.
Our planet, the only home we have in the vast reaches of the known universe, is overheating, so far uncontrollably. It has been doing so for a long time now, since before we became aware of it, and has shown no sign of slowing down, even though some of the more learned and wise among us have finally acknowledged it.
Glaciers melt, ocean-levels rise, moderate zones become sub-tropical, drought ravages formerly-fertile lands, famine spreads, extreme weather-events increase in frequency worldwide, wildfires rage. And most ominously, global freshwater reservoirs are shrinking.

Like the oncologists my wife and I depended on to deal with our own Cancers, earth-scientists have conducted their tests, studied the results, and announced their diagnoses. As they see it, climate change is the existential crisis of our time, the Cancer that has the potential to bring about the demise of human life on Earth as we know it.
We ignore these warnings at our peril.
The hope, of course, is that advances in science and technology will merge with the ingenuity of humankind to arrest the changes that are upon us. But even the most optimistic do not profess to believe the changes can be reversed. Just as there is no guarantee my wife and I will remain Cancer-free forever, there is no assurance our Earth will fully recover from the climate-Cancer assailing it.
But we must deal with it. And soon.
The Cancer has no mercy.