
My co-presenter at last weekend's Carbon Neutrality Unconference, smart-guy Pete Erickson of Stockholm Environment Institute, used four slides that are worth sharing again. Taken together, they're an excellent -- if somewhat wonky way -- to think about the basic structure of reducing emissions.
1. What are the cheapest reductions?

Full size image here. This McKinsey Institute chart depicts the cost of various carbon "abatement" (i.e. "reduction") strategies given current technology. The bars that fall below the horizontal axis depict abatement opportunities that pay for themselves (such as energy efficiency). The bars above the x-axis show the strategies that cost money (such as sequestering carbon from coal plants), at least given the current state of technology. The width of the bars depicts how much carbon reduction is available.
(Source: McKinsey & Company, "Pathways to a Low-Carbon Economy")
2. How far do the reductions get us?

Full size image here. Another chart from McKinsey. This one uses a "wedge" diagram to illustrate how much carbon reduction we can achieve from several major categories of abatement strategies.
(Source: McKinsey & Company, "Pathways to a Low-Carbon Economy")
3. Who takes responsbility?

Full size image here. Based on each country's population and historical contribution to climate change, this chart depicts how much carbon "budget" countries have if we were to equitably distribute the right to emit carbon in the future. The pale color shows how much a country has "consumed" (i.e. "emitted") and the dark color shows how much budget remains. The United States has a negative carbon budget, shown by the dark bar below the horizontal axis, implying that an equitable distribution of carbon resources would require the US to go beyond carbon neutrality.
(Source: German Advisory Council on Global Change, "Solving the Climate Dilemma: The Budget Approach" )
4. What does "carbon neutral" mean if we take greater responsibility?

Full size image here. A closer look at the carbon responsibility for the United States under an equitable distribution of carbon resources. Notably, the red line -- showing the "fair share" for the US -- dips below zero (net carbon neutral) by around 2025, and continues on a downward path. A significant share of the US reductions, however, are "mitigation" actions (i.e. "offsets") funded in other countries.
(Source: Greenhouse Development Rights Book, second edition)
This article comes to Worldchanging courtesy of Sightline, the Northwest's premier sustainability thinktank.
Great summary and the first graph is enlightening as it shows that the items that have the lowest cost of abatement will come down to the individual and their choices for construction and maintenance of the homes and offices. Also management of landscape and farming practices also play a great role in GHG abatement, it will take education but I think we will get there. I download the full report and I am going to read it thoroughly. Thanks Eric & Pete for bring this to our attention.
Conspicuously absent from the graphs are any calculation of reforming land use to increase quality of life, reduce infrastructure cost, and, of course, reduce carbon emissions. Why was this not a factor in the McKinsey study?
For a good starting point in looking at the potential effects of smart growth on climate, http://www.smartgrowthamerica.org/climate.html
All of these graphs are interesting and good (I'd never seen the last two before). What is always lacking for me, especially with the first Mckinsey chart is the absence (simplification) of timing. Timing matters. How long does it take for any of the noted possibilities to produce real CO2 reductions?
Answer: a long time for the vast bulk of them.
Missing is behavior change. Sure, it is hard, but it is the only thing that is going to get us to where we need to go in the time required. And maybe, we've already lost that battle. Here is a blog I wrote a couple of years ago (!!) that has a nice table illustrating the length of time it will take for particular actions to produce real CO2 reductions.
Slide 3 presents the idea that we might be able to "to equitably distribute the RIGHT to emit carbon in the future." (capitalization for emphasis) Where does this RIGHT to emit carbon come from? Is this an inalienable right, or something more temporal and convenient?
