Page 35 - Green Builder Nov-Dec 2021 Issue

Carbon phase-out. The “City by the
Bay,” a.k.a. San Francisco, is one of
many California cities that’s saying THE STATE OF
goodbye to new natural gas-powered SUSTAINABLE
homes and switching to all-electric
BUILDING 2022
by 2022. CREDIT: GREEN BUILDER MEDIA

Where Fresh Air Isn’t

One of the biggest sources of carbon emissions comes from inside U.S.
(and world) households. According to the U.S. Environmental Protection
Agency (EPA):
Approximately 70 million American homes burn natural gas, oil, or
■
propane on site to heat interior space and water.
This generates 560 million tons of CO2 each year—one-tenth of total
■
U.S. emissions and just under half of all residential end-use energy
consumption nationally.
Gas stoves also emit pollutants such as nitrogen dioxide and carbon
■
monoxide into the home, resulting in asthma and other ailments.
Everyday indoor activities, such as cooking meals, can enable those
invisible pollutants to easily reach levels that would be illegal outdoors.

solid rock within a couple years. Swiss clean air technology manu-
facturer Climeworks recently went online in Iceland with Orca,
the world’s largest direct air capture plant. It’s capable of drawing
down 4,000 tons of CO2 annually—about the amount that 790
passenger vehicles pump out in a year.
Carbon utilization. This process of taking carbon particles
out of the air and infusing them into products is necessary for
highly intensive industries like concrete, asphalt and steel. One
method, mineralization, transforms CO2 into mineral carbonates,
which can be used to make concrete and cement. Because these
building construction materials are used at an enormous scale
and have product lifetimes that span decades, mineralization
“represents a significant opportunity for long-term carbon stor-
age as well as utilization,” according to the National Academies CREDIT: ISTOCK/PEOPLEIMAGES
of Sciences, Engineering and Medicine. A variety of processes
that use carbon dioxide in the production of concrete and cement
are already operating at limited commercial scales.
Other technologies use chemical and biological processes to
transform CO2 and methane into fuels, polymers and chemi- Global Greenhouse OTHER
cals. Some of these processes are already producing high-value Gas Emissions by ENERGY
chemicals, National Academies notes. Economic Sector 10%
But being able to use technology to reduce GHGs is only part ELECTRICITY AND HEAT
of its environmental benefit. The process also assigns a value to Building up heat. INDUSTRY PRODUCTION
CO2 and changes the way people think of the gas, according to Greenhouse gas (GHG) 21% 25%
COGNITION. emissions from the
There are also government incentives. More than $20 million Buildings sector result
has already been allocated to companies that have sequestered from on-site energy
or reused carbon in products. Another $6 billion has been ear- generation, and burning AGRICULTURE,
marked for companies developing carbon capture, storage, and fuels for heat in buildings TRANSPORTATION FORESTRY AND OTHER
utilization technologies. And Congress is considering the Storing or cooking in homes. But 14% LAND USE
24%
CO2 and Lowering Emissions Act (SCALE) Act, a $5 billion plan they’re the smallest
calling for an infrastructure to transport carbon dioxide from the source of GHGs when BUILDINGS
sites of capture to locations where it can be utilized in manufac- stacked against other 6%
turing or sequestered safely and securely underground. GB parts of the economy.
SOURCE: INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE
www.greenbuildermedia.com November/December 2021 GREEN BUILDER 33