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Last month, the G8 – the eight largest nations in terms of their economies – agreed to a 50% reduction in global carbon emissions by 2050. In a related move a few weeks earlier, the Waxman-Markey bill passed the House, bringing a carbon-constrained economy one step closer to the U.S. Supporters and detractors reacted with predictable fury. If you take the inadvisable approach of listening to both at once, you might believe these steps will fail to save the planet while destroying our economy.
The science and policy tools surrounding cuts in emissions are complicated, and even figuring out what one personally thinks about these matters is difficult. It was around this time that I attended the 2009 Berkley Workshop on Land Conservation and Energy Infrastructure in Tarrytown, NY and the invigorating discussions there helped me get my own thoughts in order.
Here’s the bottom line: the overall concentration of carbon dioxide in the atmosphere is what matters. Too high a concentration is bad news, and leads to melting ice caps, rising sea levels and a lot of complex effects that we don’t yet fully understand. Before the Industrial Revolution, the amount of CO2 was around 280 parts per million (ppm). According to latest numbers from NOAA, the concentration is 390 ppm today – and rising. The best science out there suggests keeping overall concentration below 450 ppm this century is only somewhat likely to avert catastrophic effects, with 550 ppm probably much worse. I’ll take 450 ppm rather than the catastrophes, thanks, though all indications look like we’ll exceed it anyway.
Carbon dioxide stays around for a long time – hundreds of years, and the atmosphere is a finite place. So keeping overall concentration at 450 or 550 or any other concentration requires us to set an overall carbon budget that cannot be exceeded. It’s like having a delicious cake: we can eat it now, or save some for later. However we choose to eat it, there’s still only one cake. Except, with emissions we can pig out and eat more than we should, by emitting so much carbon dioxide that overall emissions rise above a safe level. To extend the cake analogy, we’re now eating someone else’s cake, and if we don’t pay back things are going to get very hot for us. Going over 450ppm will require us to pull carbon dioxide out of the atmosphere and store it, in order to get back below the safe level.
That carbon budget isn’t just for a few years until this climate change thing passes by. It’s forever. As long as human life keeps going on Earth, we’ll be limited to having 450 parts per million of carbon dioxide over our heads. As a society, we need to go from producing vast emissions of CO2 to carbon neutrality, and then some: we need to become carbon negative. Over the next century, we face the necessity of keeping billions of people alive and living well while simultaneously reducing the overall amount of CO2 in the atmosphere. This is a staggering challenge. This is why cuts in emissions aren’t the whole story – they are a start, but we can’t just cut emissions in half and be okay. We need to cut, cut, cut, cut and then stop emitting. Are we up to it? I don’t know.
While our region may be one of the most sustainable places to live in the nation, and the most energy efficient and low-carbon place to be, we still emit a lot of CO2. Last time I counted it up, my own footprint was somewhere between 7-11 tons/year including all travel, waste and energy. Getting from 11 tons to zero tons is a big task, bigger still for an auto-dependent suburban family in an inefficient house. A carbon-negative economy will change everything: where we live and travel, how we build and use land, how energy is generated, the products and food we consume. We don’t have much time. Can we do it? I don’t know. Are current trends encouraging? Not really.
And yet… human nature is optimistic. These could be amazing years for brilliant policy making, for full carbon cost accounting, for innovation in new technologies, for human resourcefulness and community and hope – and planning?
By Frank Hebbert, Associate Planner, RPA
