Wilson da Silva

Science journalist, feature writer and editor.

Apr. 1, 2013
Published on: Cosmos Magazine
6 min read
OPINION | Mother of All Challenges
A 260,000 square kilometre sunshield in orbit between Earth and the Sun [Art by Jamie Tufrey]

Here’s what I think is going to happen over the next 50 years.

By Wilson da Silva

ANY DAY NOW, I will become a father. And like any new parent, and many people who are already parents, I find myself thinking more acutely about the future. Mostly, it’s about the mundane but important machinations of daily life. Until recently.

Not long ago, I caught up with Carin Aquiline, a dear American friend I hadn’t seen since Cosmos launched 50 issues ago. She’s a long-time fan of Cosmos, which may be why she posed this question: “How do you reconcile what you’ve written about the looming hazards of climate change in the decades ahead, with the fact that you’re about to become a father?”

It’s one thing to talk about the future in the abstract, and quite another when you have, as it were, ‘skin in the game’. And it’s a question I hadn’t considered, until Carin – herself a mother of two young boys – coaxed it out.

So here’s what I think is going to happen over the next 50 years.

Little will be achieved in the drawn-out diplomatic effort to strike global agreements to reduce greenhouse gases. What is achieved will be far too little, too late. Some nations will make dramatic strides forward to generate low-carbon energy and reduce their reliance on fossil fuels; some will succeed in notable initiatives but fall short on the big picture; and most nations will, I suspect, pay lip service and dawdle.

And none of it will affect the incessant climb in the world’s average temperature; this will continue to spike higher as our annual emissions add more layers of heat to the thermal blanket of carbon dioxide (CO₂) already in the atmosphere from emissions over the past 100 years or more.

Greenhouse gases such as CO₂ take up to 500 years or more to be cycled out of the air, so what is warming the planet today is largely a combination of today’s emissions and those from every year since the Industrial Revolution.

At best, I suspect atmospheric CO₂ will reach 550 ppm (parts per million) by 2050; about 40% higher than today’s estimated high point of 396.80 ppm.

Global average temperatures will climb by 2.5°C to 3°C above preindustrial levels – enough to disrupt rain patterns farmers rely on, and for glaciers to largely disappear. In some parts of the world – Vietnam, Bangladesh and Indonesia, for example – sea-level rise will render some cities and towns uninhabitable, as seawater reaches inland and causes erosion, flooding of wetlands, the contamination of aquifers and agricultural soils and the destructive loss of habitats for fish, birds and plants.

Extreme weather events will intensify, at times to unprecedented levels. There’ll be hundreds of billions of dollars in property damage annually. In the years ahead, almost 100 million people will die as a result of climate change.

Finally, when our backs are against the wall, we’ll act. As humans so often do: we seem to be at our best in a crisis.

I don’t mean that humanity will finally reduce emissions dramatically – it’ll be far too late for that. The CO₂ blankets will be piled too high, there’ll be too much heat trapped in the atmosphere, and temperatures will already be threatening to cross a tipping point that might see them accelerate higher. No, it’ll be crunch time.

It’s simple, really: if we can’t reduce the rate at which heat is being trapped by the atmosphere fast enough, we’ll have to reduce the amount of heat entering it in the first place. That means reflecting more sunlight back into space – and that means large-scale dispersal of aerosols in the stratosphere, building massive reflectors in deserts or constructing a 260,000 km² sunshield in orbit between Earth and the Sun.

My preference would be for a sunshield, since this would have less localised impact on the biosphere and could be applied to the planet as a whole, reducing global average temperatures down by 1.5˚ C. This would stabilise global temperatures and begin pushing them lower within a year.

It would cost hundreds of billions, maybe even trillions, of dollars – perhaps the equivalent of an Iraq War or two. But it will reduce catastrophic warming, buy humanity time to shed its addiction to fossil fuels and ratchet down emissions to sustainable levels – levels the natural carbon cycle of the planet can process.

Some argue that this is the easy way out. I disagree. The loss of lives, property and treasure that will precipitate such global action, along with the cost of the geoengineering itself, will ensure we take emissions seriously – and fundamentally rearrange our civilisation so this never happens again.

Am I worried about climate change? Yes, of course. But I know that humans are at their best in a crisis, I know we’re a clever, inventive species, and I think civilisation will pull through. And I think the world that emerges from this will be the better for it. Here's to hope.