Audio version read by George Atherton – Right-click to download

I have come to the conclusion that our human society and economy is now so large that we have passed the limits of our planet’s capacity to support us.

Our current model of economic growth, the one we rely upon for our present and future prosperity, is driving us over the cliff. This means things are going to change. Not because we will choose change out of philosophical or political preference, but because if we don’t transform our society and economy, we risk social and economic collapse and the descent into chaos. The science on this is now clear and accepted by any rational observer. While an initial look at the public debate may suggest controversy, any serious examination of the peer-reviewed conclusions of leading science bodies shows the core direction we are heading in is now clear. Things do not look good.

These challenges and the facts behind them are well known by experts and leaders around the world and have been for decades. But despite this understanding, that we would at some point pass the limits to growth, it has been continually filed away to the back of our mind and the back of our drawers, with the label “Interesting – For Consideration Later” prominently attached. Well, later has arrived. This is because the passing of the limits is not philosophical but physical and rooted in the rules of physics, chemistry and biology. So passing the limits has consequences. If you cut down more trees than you grow, you run out of trees. If you put additional nitrogen into a water system, you change the type and quantity of life that water can support. If you thicken the Earth’s carbon dioxide blanket, the Earth gets warmer. If you do all these and many more things at once, you change the way the whole system of planet Earth behaves, with social, economic and life support impacts. This is not speculation, this is high school science.

In all this though, there is a surprising case for optimism. As a species, we are good in a crisis, and passing the limits will certainly be the biggest crisis our species has ever faced. Our backs will be up against the wall, and in that situation we have proven ourselves to be extraordinary. As the full scale of the imminent crisis hits us, our response will be proportionally dramatic, mobilizing as we do in war. We will change at a scale and speed we can barely imagine today, completely transforming our economy, including our energy and transport industries, in just a few short decades. Perhaps most surprisingly we will also learn there is more to life than shopping. We will break our addiction to growth, accept that more stuff is not making our lives better and focus instead on what does.

This is why we shouldn’t despair in the face of what the science is telling us – it is precisely the severity of the problem that will drive a response that is overwhelming in scale and speed and will go right to the core of our societies. It is the crisis itself that will push humanity to its next stage of development and allow us to realize our evolutionary potential. It will be a rough ride, but in the end, we will arrive at a better place. By coincidence, this story also spans my lifetime. As I was being born in Australia in 1959, the start of this dramatic story was unfolding in the US. The US Department of Agriculture banned the sale of cranberries, just before Thanksgiving, due to the poisoning of the national crop by the excessive use of inadequately controlled pesticides. It was what I consider the beginning of modern environmental awareness. It was the moment people on a large scale started to wake up to the fact that there were limits to the Earth’s capacity to cope with our abuse, that we had grown so powerful as a species that we had now acquired a fateful power to destroy nature, as scientist Rachel Carson stated. It was when people came to realize that while we had for 10,000 years learned to control nature around our houses, villages and farms for our immediate benefit, the scale of our impact had now changed the game.

Environmentalists such as myself also have to acknowledge a sobering reality in this. Given that we were unsuccessful in convincing society to respond to the challenge that was coming, there must have been failings in the approach we took. While I too lament the result and wonder what we could have done differently, I have now moved on. It is what it is. We can only change the future. We all know where we’re heading. We know it from the science, we know it from the politics, and we know it in our hearts. That’s why I get so little push-back. We know. We’ve been borrowing from the future, and the debt has fallen due.

The science says we have physically entered a period of great change, a synchronized, related crash of the economy and the ecosystem, with food shortages, climate catastrophes, massive economic change and global geopolitical instability. It has been forecast for decades, and the moment has now arrived. We now need to get ready. We can manage our way through the hurricane, but only if we acknowledge its coming and are clear first on how we will survive it and then on what our recovery plan is. History is full of evidence that when our backs are against the wall, all the great qualities of humanity, our compassion, our drive, our technical brilliance, and our ability to make things happen on a massive global scale, come strongly to the fore.

Yes, it is also true we have a shadow side, left over in our reptilian brains, that can take us to a bad place, where fear and anger reside. In the circumstances now emerging, this kind of response could lead to the breakdown of society. So, yes, we could choose to have a dog-eat-dog response drive us into ever-smaller conflicting groups of regions, nations and communities of defensive and scared people fighting over what’s left, fighting for physical survival. I don’t believe we will do this. Given our natural survival instincts, our history as a species, our new global connectedness and the scale of the threat, I believe we will instead choose to consciously overcome that tendency, as we have many times in the past. It is true that the crisis coming will almost certainly see great conflict among nations over resources and refugees, mass suffering, and some difficult situations emerge as fear and nationalism rear their ugly heads. We need to plan for all of this. However, we will also see the best humanity can offer, great compassion, extraordinary innovation, and millions of people digging deep and finding their capacity for brilliance and innovation.

We have the opportunity to build a society that represents our highest capacities, with extreme poverty eliminated; great technology that works with rather than against nature and provides us with abundant energy and resources; a closed-loop economy with no waste; communities that work and support one another. The global nature of the problem means only a global solution can fix it, and that means we are going to come together as a people like never before. Protecting national interest will have to be confined to the sporting field. Again, not just because we might choose to, but because it is the only way we can address the challenges we face.

Paul Gilding is a former global chief executive of Greenpeaace. This editorial is excerpted from his latest book, The Great Disruption: How the Climate Crisis Will Transform the Global Economy.