I am old enough to remember 1976. In the UK that was the year of the long hot summer, of water standpipes in the street and the first murmurings of a new wave of music called punk rock. In some ways it seems not so long ago, but 1976 is as far back from now as it is forward to 2050. Given how much the world has changed since the mid-1970s, it is perhaps no surprise that Jonathon Porritt’s new book about the mid-21st century presents a radically different place from the one we know today.

For anyone paying attention to the different reports being published on a range of global trends, then very different it will need to be – if it is to support the needs and comfort of nearly 9 billion people, while navigating the multiple pressures of climate change, rising demand for food, declining renewable resources and ecosystem degradation.

Porritt presents this future world from the point of view of a fictional character called Alex McKay. McKay is a teacher and has tasked his students to trace the events and breakthroughs that shape their lives in 2050. The book is a summary of what they found out.

Among the world-changing landmarks picked out by McKay and his students is the point at which solar power became cheaper than that from fossil fuels. Another is the introduction of a nationwide carbon-reduction programme to the US (by a Republican administration). The world’s coral reefs are in a period of recovery while fish populations across the oceans have bounced back in the wake of more intelligent management. Natural systems are appreciated because of the economic value they provide, including the tropical forests that are subject to more effective conservation because of an international mechanism helped into being by the man who is, in the 2020s, the UK’s King Charles III.

There are smart cities that produce not only much of their own power from renewable energy, but also about 15% of the world’s food; countries are connected by super-efficient electric-hybrid aircraft and stately airships, while most road transport is electric and propelled by super-efficient batteries. A circular economy has been largely achieved, with waste virtually eliminated through new design, technology and changed consumer behaviour. A whole range of energy storage devices have placed intermittent renewable energy sources at the centre of economies worldwide, and both international education and health programmes are funded to the tune of trillions of dollars from a financial transaction tax.

The events and breakthroughs that brought the world toward these and other positive outcomes are chronicled in a fascinating narrative that places speculative (but plausible) landmarks into ‘history’ written from the future. For example, a more intelligent approach to food security is stimulated by a massive famine in the 2020s that kills millions of people. Nuclear power is phased out due to a near-disastrous cyber attack on stations in the UK and the US.

Additional drivers for change come in the form of new political agreements, and from the world’s major faiths finally taking decisive action. A global campaign to reduce food waste is one example of how they eventually deploy their implicit moral agenda to practical effect for sustainability. Inevitably, however, a lot of what Porritt describes is down to the adoption of new technologies. And this is where, for some readers, there will be an instinctive rejection of the picture he paints.

Among expected future developments that will cause alarm for some is the introduction during the 2020s of wheat that has been genetically modified to fix nitrogen. Another is the use of synthetic biology for the development of new microorganisms that make the raw materials for new biofuels. Nanotechnology has a big role, as does the application of advanced genetic technologies in personal health care. Synthetic meat is also on the menu. There are caveats to the technology focus, however. In relation to agriculture for example, Porritt suggests that a bigger contribution to future food security will come from increases in productivity by smallholders, rather than from genetically modified plants.

While the content is strong, compelling and provocative, I wasn’t taken by the visual style. There are great images, but the layout and design didn’t connect very well with me as a reader. When it comes to the cover I think Porritt should have urgent consultations with his publishers. It doesn’t really work. His name is nearly nowhere, and the bland yellow cover does no favours to the massive intellectual effort contained within. There were also questions for me about the target readership. I liked it very much, but what is the mass-market opportunity?

Porritt knows very well that even among his warm audience not everyone will agree with his projections, and that, in some ways, is a big part of the value of this book. By provoking readers into addressing the question “If not that, then what else?” The World We Made should get a lot of people thinking outside their boxes and cosy comfort zones.

And as the anti-‘technofix’ chorus pipes up, it is important to say that Porritt himself is quite clear the ‘technotopia’ he sets out is no panacea. For those who still reject his scenarios, then comes the challenge of setting out alternative pathways. If cultural, spiritual and philosophical revolution is the alternative to technology, then what would be the pathway to a sustainable 2050 through those frames? What would be the trigger points, the change agents and drivers of new ways of thinking?

While Porritt has gone out of his way to stretch our possible future to be an optimistic one, this is at times still not a comfortable read. But since we are in a rather uncomfortable position, this is perhaps to be expected. While no one can predict the future, at least one thing is for sure, and that is how carrying on as we are now will court disaster. The really tricky thing is what to do about it. This book will be an important contribution in that debate.

Tony Juniper is the author of What Has Nature Ever Done for Us?