Every April we show the latest energy flow chart from the Lawrence Livermore National Laboratory, which are “single-page references that contain quantitative data about resource, commodity, and byproduct flows in a graphical form.” I have called it The Chart That Explains Everything.

© Lawrence Livermore National Laboratory and the Department of Energy

For the last few years I have been looking at this chart and noted that our single biggest problem is not the building sector but in fact the transport sector, thanks to that big honking green bar at the bottom. And indeed, when you compare it to 2014, transport energy use is up by .8 of a quad, significantly more than the entire installed base of solar power. I have written that getting people out of cars is the most important thing we can do; hence the preoccupation with walkable and cyclable cities. I wrote last year:

Solar panels are lovely things, but the only way we are going to solve this problem is to stop designing our world around the car, to design homes and buildings that need significantly less cooling, and to get a bike.

USGBC/via

I have also questioned this pie chart and the assumption of Ed Mazria and the 2030 Challenge that buildings are our biggest problem, and the architectural community’s preoccupation with building energy consumption instead of urban planning, suggesting that transportation was in fact the biggest offender, the biggest generator of carbon dioxide.

But I now believe that I have been reading this wrong all this time.

© Lawrence Livermore National Laboratory and the Department of Energy

If you look at the last year that Livermore did a flow chart for CO2 output, 2014 the single biggest source is the production of electricity, at 2040 million metric tons (MMT).

© Lawrence Livermore National Laboratory detail

However when you look back to the energy consumption graph, the commercial and residential sector are using 9.44 quads, or 74.9 percent of all the electricity. That is 1528 MMT, mostly for air conditioning. Add the CO2 created directly by commercial and residential buildings and they total 2101 MMT, or 38.84 percent of the total CO2. Transportation uses 33.82 percent, and industry, 27.34.

Lloyd Alter/ pie chart of 2014 carbon emissions /CC BY 2.0

So the 2014 pie chart looks pretty much like Ed Mazria’s 2004 pie chart, and I have been wrong in claiming that transportation is a bigger source of CO2 than buildings. About the only thing that I can say is that transportation is going up while buildings are getting better, down by .8 of a quad since 2014.

Two years ago I concluded:

So basically it’s the car, driving to air conditioned sprawl, that’s responsible for as much as 71% of our carbon emissions. Changing light bulbs doesn’t fix that. Really, we have to do everything we can to get people out of their cars, and into walkable communities in temperate climates. Everything else is just gnawing around the edges.

But I was wrong to suggest that transportation is a bigger problem than our buildings. How we get around is obviously still critically important, and is going in the wrong direction. But what we build in fact does matter more.

Related on TreeHugger.com:

• Lessons from Livermore: Look at the big picture to figure out where we have to go
• Latest look at the Lawrence Livermore graph that tells you everything you need to know about America’s energy use