A fascinating article at Foreign Policy:
These scientists are beginning to look for a Plan B. There are two distinct approaches under consideration — sucking carbon out of the atmosphere, or creating an artificial sun shield for the planet. The former, which involves reversing some of the very processes that are leading to the climate problem, is expensive.
A sun shield?
If the world can’t get its act together to limit carbon emissions, geoengineering may be the only option we have. Distill the climate problem down to the essentials, and it becomes obvious that global warming is fundamentally a market failure: All seven billion of us human beings are “free riders” on a planet that is heating up. We put billions of tons of carbon dioxide into the atmosphere every year, and largely aren’t required to pay for the privilege. There’s too little incentive to stop polluting. …
“Free riding” also plagues relations between countries. Some, like the European Union have a cap or tax on carbon pollution. Most are still waiting on the sidelines. Why should any single country cut its carbon emissions when it knows that its reductions will only be a drop in the bucket toward solving climate change — and other nations aren’t asking their citizens to pay their fair share? Blame it on short election cycles, partisanship, or fossil energy interests, the political will often doesn’t exist — whether in Washington or the latest global environment gathering in Rio de Janeiro.
Yep, unless China and India are part of any agreement, other countries won;t commit.
“Free riders” are only half the problem. “Free drivers” may be as important. The allure of geoengineering derives from the simple fact that – given what little we know about it at the moment – it appears to be a comparatively cheap way to combat climate change. And it doesn’t take a global agreement to act. It takes one actor – one country – in the driver’s seat.
If, for example, the very existence of an island, nation, city, or agricultural region is threatened by global warming, the question among its leaders will no longer be whether geoengineering is an option, but what the effects, positive and negative, might be and how it could be carried out. That’s also where the science stands today, and the economics points in the same direction.
This makes sense. Something one or more countries can do by themselves, without the need for universal support.
In fact, the price tag of these geoengineering strategies is likely to be negligible relative to the purported benefits: Columbia University’s Scott Barrett, among others, has calculated that it would cost pennies to offset a ton of carbon dioxide from the atmosphere. By comparison, it costs dollars per ton to reduce carbon dioxide emissions in the first place.
And much cheaper.
What makes scientists believe geoengineering could work? It’s been tried before – by nature, not by humanity.
When Mount Pinatubo erupted in June 1991, it forced the evacuation of 200,000 Filipinos and shot 20 million tons of sulfur dioxide into the stratosphere. The added sulfur counteracted the effect of 1,100 billion tons of carbon dioxide that had been accumulating in the atmosphere since the dawn of the industrial revolution. In 1992 and 1993, it decreased global temperatures by a bit less than 1 degree Fahrenheit by reducing the amount of sunlight that hit the earth’s surface. That was about the same amount temperatures had risen at that point from carbon added to the atmosphere by human activity. In other words, Mount Pinatubo alone offset all temperature increases from the beginning of the Industrial Revolution.
So all we need is to have more volcanoes erupt!
As the article makes clear, geoengineering has considerable risks and side-effects. But with the major emitting countries unwilling to cap carbon emissions, it may well be that one or more countries turn their attention to geoengineering.