How fast can we transition to a low-carbon energy system?
The total value of all this infrastructure is on the order of US$10 trillion, or nearly two-thirds of US gross domestic product. Nothing that huge and expensive will be replaced in a year, or even a few years. It will take decades.
Yet there is good news, of a sort, in the fact that all infrastructure eventually wears out. A 2010 study asked: what if the current energy infrastructure were simply allowed to live out its useful life, without being replaced?
The surprising answer: if every worn-out coal-fired power plant were exchanged for solar, wind or hydro, and every dead gas-powered car replaced with an electric one, and so on, we might just stay within our planetary boundaries.
According to the study, using the existing infrastructure until it falls apart would not push us past the 2 degrees Celsius global warming that many scientists see as the upper limit of acceptable climate change.
The problem, of course, is that we aren’t doing this yet. Instead, we’re replacing worn-out systems with more of the same, while drilling, mining and building even more.
.. In Queensland, Australia, over 20% of homes now generate their own electricity. This example suggests the possibility that a “tipping point” toward a new social norm of rooftop solar has already been reached in some places. In fact, a recent study found that the best indicator of whether a given homeowner adds solar panels to a house is whether a neighbor already had them.