Coal use for electric power generation has been, mercifully, falling off a cliff since 2007 or so (Figure 7.2 from the EIA’s July 2016 Monthly Energy Review). Since buildings make up most of electricity demand in the EIA’s Residential and Commercial sectors, this drop in coal use has lead to a drop in the emissions from buildings (Figure 12.2 also from EIA’s July 2016 report).
Ed Mazria of Architecture 2030 has been pointing out the central role buildings play in reducing emissions, because of their longevity, because they use mostly electricity, and because coal has provided the largest share of electricity generation. Mazria (and many others) have focused on making better buildings and, in a time with expensive photovoltaics and coal the dominant fuel, this seemed to be our only option. Buildings have seen improvements as revealed by the flattening curve in Figure 2.1 (especially against a background of growth), but the collapse of coal seems the biggest contributor to emission reductions.
With the now low, and rapidly falling, cost of photovoltaic and wind generation — and their rapidly increasing share of electric production (Fig 12.2 indicates renewables at about 20% that of coal in 2006, jumping to more than 30% today, just 10 years later), we can expect building emissions to continue falling dramatically. Lucky for us, better buildings will contribute to reduced emissions, but are not our only hope for reductions.
Transportation emissions are still high. They fell some with the 2008 economic crisis, but seem to have leveled off and even increased with low motor fuel prices and a recovering economy. The good news here is that electric vehicles have just started up their growth curve and with most major auto makers following Tesla’s lead, and trucks, buses, and even ferries, all heading rapidly towards electric, the adoption rate could be fast indeed.
All of this against the backdrop of a steady increase in what I think of as “energy productivity”, the amount of economic activity per unit of energy consumption (Fig 1.7). Today, we have roughly 3 times the economic active per kWh as we did in 1950. Prospects for continued gains in energy productivity, renewable generation, and motor vehicle electrification is (very) good news.