Evolution of science and implications for humanity
PAS Academician Martin Rees
Food systems are far from my expertise as an astronomer. But I’m a Council member of the Pontifical Academy, and the President has invited me to make brief comments from a broader perspective.
First a few words on the overall scientific landscape. Science has two fundamental frontiers: the very small (atoms and particles) and very large (the cosmos). But these frontiers concern less than one percent of scientists. 99 percent work on a third frontier: the very complex. Even the smallest insect, with its layer upon layer of intricate structure, is far more complicated than a star or galaxy. And ecological systems are more complex still.
So I defer to everyone here who is tackling systems far more complex – and challenges far more urgent – than my own specialist concerns. And I speak less as an expert than as just an anxious member of the human race.
Our Earth has existed for 45 million centuries. But this century is special: it’s the first when the main threats are induced by one species, humans. We’re deep in the anthropocene. We have an ever-heavier collective footprint on the planet. We’re empowered by ever more powerful technologies that can be hugely beneficial, but which if misapplied could trigger catastrophic setbacks to civilization. And such events would be global: we’re so interconnected that no continent would be unscathed. For this, Covid 19 has been a wake-up call.
The world is getting more crowded. Fifty years ago, its population was below four billion. It’s now about 7.8 billion. But doom-laden forecasts – by Paul Ehrlich and the Club of Rome – proved off the mark. Food production has kept pace with rising population. Famines still occur, and there’s widespread undernourishment, but these evils stem from conflict or maldistribution, not overall scarcity.
The number of births per year is now going down in most countries. Nonetheless world population is forecast to rise to around 9 billion by 2050. That’s partly because most people in the developing world are young: they are yet to have children, they will live longer. And partly because the demographic transition hasn’t reached some of the poorest countries.
Avoiding mass hunger will require further-improved agriculture – low-till, water-conserving, and GM crops – and maybe dietary innovations: converting insects – highly nutritious and rich in proteins – into palatable food; and eating artificial meat and not beef. To quote Mahatma Gandhi – enough for everyone’s need but not for everyone’s greed.
Optimists say that each extra mouth brings two hands and a brain. But the geopolitical stresses, especially if North-South inequalities aren’t reduced, are surely worrying. Those in poor countries now know, via internet, etc, what they’re missing – they’re not fatalistic about the injustice of their fate.
And another thing: if humanity’s collective impact pushes too hard, the resultant ‘ecological shock’ could wipe out many species – we’d be destroying the book of life before we’ve read it.
Already, the biomass in humans, cows and domestic animals is 20 times that in wild mammals. And chickens and turkeys outnumber all the world’s wild birds. Biodiversity is crucial to human wellbeing. We're clearly harmed if fish stocks dwindle to extinction; there are plants in the rainforest whose gene pool might be useful to us. And insects are crucial for the food chain and fertilization. But preserving the richness of our biosphere has value in its own right – as proclaimed in the encyclical Laudato Si’. To quote a secular sage, E.O. Wilson, ‘mass extinction is the sin that future generations will least forgive us for’.
To avoid massive encroachment on natural habitats, ‘sustainably intensive’ agriculture must be a goal. Moreover, these pressures are aggravated by anthropogenic climate change. Under ‘business as usual’ scenarios we can’t rule out, later in the century, really catastrophic warming, and tipping points triggering long-term trends like the melting of Greenland’s icecap. That’s why developing clean energy systems – carbon-free generation, cheap storage and efficient distribution – is another global imperative
It’s hard to conceive more inspiring goals for young scientists, technologists and engineers than to ensure sustainable food and energy supplies worldwide in the coming decades. This year we see not only the UN food systems meeting that we’re focused on here, but also two other crucial UN conferences: climate change (COP26) in Glasgow; biodiversity in Kunming.
The case for urgent action is compelling. But politicians won’t prioritise long-term decisions unless there’s public clamour from their voters. Scientists must enhance this clamour – by engaging with NGOs, via blogging and journalism, and enlisting charismatic individuals and the media to amplify their voice.
Pope Francis’s 2015 encyclical had a worldwide influence in the lead-up to COP20 in Paris. There’s no gainsaying the church’s global reach, long-term vision and concern for the world’s poor. And it’s welcome that his sentiments are amplified by many others – especially by the diverse trio of David Attenborough, Bill Gates and Greta Thunberg. It’s encouraging to witness more activists – especially among the young, who may see the dawn of the 22nd century. Their commitment gives grounds for hope.
Finally I offer a few cautionary words about our cosmic habitat and the rope of space science. During this century, the entire solar system will be explored by flotillas of tiny robotic craft. But will people follow them? A few may. But don’t ever expect mass emigration from Earth. It’s a dangerous delusion to think that space offers an escape from Earth's problems. Coping with climate change is a doddle compared to terraforming Mars. There’s no ‘Planet B’ for ordinary risk-averse people. We must cherish our Earthly home.
Indeed, a cosmic perspective actually strengthens our concerns about what happens here and now, because it offers a vision of just how special our Earth is, and how prolonged and prodigious life’s future could be. In the aeons that lie ahead, even more marvellous diversity could emerge. The unfolding of intelligence and complexity could still be far from its culmination. We’re all surely mindful of the heritage we’ve inherited from our forebears. If our generation are negligent stewards – ‘poor ancestors’ as it were – we shall not only jeopardize the welfare of our children and grandchildren but risk foreclosing vast future potentialities
“Space-ship Earth” is hurtling through the void. Its passengers are anxious and fractious. Their life-support system is vulnerable to disruption and break-downs. But there’s too little planning, too little horizon-scanning, too little awareness of how interconnected we are. We need to think globally, we need to think rationally, we need to think long-term – empowered by twenty-first-century technology but guided by values that science alone can’t provide.
Let’s hope these sentiments gain traction in what’s going to be a crucial year.