When I was in high-school, I had virtually no knowledge or understanding of what Sustainable Development was, and even less of an understanding about the economic challenges our society faces. Then I read 'The End of Poverty' by Jeffrey Sachs and my mindset drastically changed. I suddenly grew a strong appetitie to better understand the world and my mental horizons expanded tenfold. That one book galvanized my passion for matters of sustainability more than anything else, before or since.
From the first time I read the book, Professor Sachs instantly became one of my favorite authors and economists of all time. His work made such an impression on my life that I later went on to obtain my Masters in Sustainability Management from The Earth Institute at Columbia University, which he directed from 2002 until 2016, and remains involved with. I graduated in May of 2019 and am incredibly grateful and fortunate to have had that unique opportunity.
I recently read Professor Sachs new book, 'The Ages of Globalization' in which he turns to world history to shed light on how we can meet the needs of today's most urgent problems. A thorough review of the book is not the aim of this post, but I will say that (just like the rest of his writings) I cannot recommend this book highly enough.
What I intend to focus on in this post is a central question Sachs poses in Chapter 8 of the book. In the section titled "The Challenge of Planetary Boundaries" on page 187, Sachs asks:
Is there not an inherent contradiction between the endless growth of the world economy and a finite planet?
It's asked in a rhetoric manner, and of course, the answer is an overwhelming 'Yes'. It's abundantly well established and understood that we are plundering our planet's resources at an alarming rate. This cannot persist for much longer without wreaking unrepairable damage on our planetary and biological systems.
But if the answer is so straightforward, and the consequences so dire, why has it proven so difficult to reorient/realign our global economic engine on a more sustainably-oriented pathway?
After posing this question, Sachs goes on to explore the dilemma more thoroughly, and in doing so he references an equation to assist the readers in conceptually understanding some of the trade-offs that may be needed to address the challenges of Sustainable Development. The equation he introduces is the IPAT equation, which aids in understanding some of the factors affecting human impacts on the environment.
**I = PAT (I = P × A × T) is the mathematical notation of a formula put forward to describe the impact of human activity on the environment. **
**The expression equates human impact on the environment (I) to the product of three factors: population (P), affluence (A), and technology (T). **
**It is similar in form to the Kaya identity which applies specifically to emissions of the greenhouse gas carbon dioxide. **
Source: Wikipedia
When used for forecasting, the accuracy of the equation has been questioned, however, that does not diminish its ability to serve as a mental model from which interested individuals can debate the impact of human activity on the environment. As Sachs explains, one basic calculation puts it this way:
**The human impact is equal to the population times GDP/population times impact/GDP, sometimes summarized as I = P × A × T, where I is impact, P is population, A is affluence (GDP per capita), and T is technology (impact/GDP). **
What is clear from this equation is that per capita economic growth (a rise in A) or population growth (a rise in P) must lead to a greater human impact (I) on the planet unless offset by an improvement in technology (lower T), in the sense of a lower environmental impact per unit of GDP.
With this example in mind, one can reasonably assume that economic growth is therefore sustainable if the rise in P and A are offset by a sufficiently large decline in T—that is, by technologies that lower the impact on the environment per unit of GDP.
The solution to that example may seem so straightforward that its almost trivial, but the bad news is that global growth during the past two hundred years has tended to be neutral or increasing in T. Society's dependence on fossil fuels, land clearing for agriculture, bottom trawling for fish, clear-cutting of tropical hardwoods, and fracking for oil and gas are all examples of technological advances that intensify the human impact on the environment. As you can imagine, the list goes on.
As Sachs goes on to explain, the good news is that there are plenty of opportunities today for major technological shifts to lower T, the human impact per unit of GDP. To name a few, Sachs lists four major themes/opportunities that can help redirect our global economy on to a more sustainably-oriented pathway. These include the shift:
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From fossil fuels to renewable energy (wind, solar, hydro, geothermal, and others), which would provide more energy with lower greenhouse-gases.
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From heavy meat-eating, especially beef-eating, toward the use of more plant proteins, which would improve human health while also reducing the pressures on land for feed grains and pastures.
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To improved building designs, which can greatly reduce the need for heating and cooling and thereby the demand for energy.
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To precision agriculture, meaning more precise applications of water and fertilizers—for example, through drip irrigation and fertigation (direct injection of the fertilizers via the irrigation system).
These four themes/opportunities represent areas of economic activity that account for the lions share of global emissions. Whatsmore, these opportunities are not outlandishly drastic to implement. This is not rocket science! We know the answers and we have the technology. What's needed is the financial products, trade mechanisms, and political willpower to make the change.
In 2016, I wrote about a similar topic, where I highlighted the investment deficit that exists in emissions-intensive industries, and the risks we run by not committing capital to these areas to continuously spur innovation. A lack of investment in these areas, especially those that are interconnected, like the water-energy-food nexus, will more than likely lead to more severe and more frequent global challenges and calamities.
Fast forward four years and the topic is as relevant now as ever before. While massive strides have been made in funding the development of clean energy, energy storage, energy efficiency systems/processes, and next-generation agricultural technologies, there is still a tremendous amount of work to be done.
In recognition that this random rambling is getting quite long, I'll end it here with another excerpt from Sach's new book, The Ages of Globalization:
Throughout most of history, humanity has been profligate with nature: use it, lose it, and move on. Yet in our time, there is no possibility of simply moving on. We have filled every nook and cranny of the planet and pushed the environmental crisis to a global scale.
The scale of the sustainability challenge is therefore unprecedented, threatening all of the planet, and all of humanity, in ways that we have never before faced. We must therefore lower T, our impact on the planet per unit of GDP.