Urging All Cities to Consider Using Carbon Dioxide Mineralized Concrete for Future City Building and Infrastructure Projects Utilizing Concrete
Adopted at the 87th Annual Meeting in 2019
WHEREAS, the Intergovernmental Panel on Climate Change, an intergovernmental body of the United Nations that is dedicated to providing the world with an objective, scientific view of climate change, reported in 2013 that the last 30 years were the warmest since 1850 and likely the warmest in the past 1,400 years; that carbon dioxide, methane, and nitrous oxide levels are at their highest levels in 800,000 years; and that global mean sea level rose 0.62 feet from 1901 to 2010; and
WHEREAS, the U.S. Conference of Mayors has supported action to reduce greenhouse gas emissions as outlined by the Mayors Climate Agreement and the Paris Climate Agreement, and
WHEREAS, the built environment accounts for over 40% of the world's carbon dioxide emissions, and the world's building stock is expected to double by the year 2060; and
WHEREAS, embodied carbon, defined as the carbon emitted through the manufacturing of materials and construction of building and infrastructure projects, will be responsible for almost half of total new construction emissions between now and 2050; and
WHEREAS, cities play a significant role in the procurement of building and infrastructure development, and infrastructure renewal is a critical need across the nation; and
WHEREAS, concrete is the most widely used construction material in the world because of its low cost, strength, and durability, among other factors, and is a significant component of many civil construction projects, such as buildings, wastewater treatment facilities, reservoirs, and transportation infrastructure; and
WHEREAS, cement, the critical ingredient that gives the concrete its strength, is responsible for up to seven percent of the world's carbon dioxide emissions, mainly through a chemical process called calcination, as well as through the use of energy in production derived from the combustion of fossil fuels; and
WHEREAS, carbon dioxide mineralized concrete is concrete that has undergone active carbonation treatment such that post-industrial carbon dioxide is injected into concrete during mixing as a beneficial reuse; and
WHEREAS, upon injection into concrete, carbon dioxide reacts with calcium ions from Portland cement to form nano-sized calcium carbonate minerals that become permanently embedded in the concrete; and
WHEREAS, utilization of carbon dioxide in concrete results in post-industrial carbon dioxide that is chemically transformed into a mineral form, which means it will never be released into the atmosphere as a greenhouse gas; and
WHEREAS, carbon dioxide mineralization in concrete has been utilized across the country by several vendors and in dozens of cities without compromising the concrete's quality, price, or construction schedules;
NOW, THEREFORE BE IT RESOLVED, that the United States Conference of Mayors calls upon its membership to prioritize utilizing post-industrial carbon dioxide mineralized concrete for use in city building and infrastructure projects involving concrete where the utilization of carbon dioxide mineralized concrete does not significantly increase the costs of or significantly delay the project.