Climate change is one of the incoming Biden-Harris administration’s core priorities. Its plan for rebuilding infrastructure would eliminate carbon emissions from the national power grid by 2035, greatly expand the availability and use of electric vehicles plus electric mass transit, and provide universal broadband. It would create jobs in climate-smart agriculture, resilience, and conservation, including the plugging of abandoned oil and natural gas wells and reclaiming abandoned mines. It also calls for upgrading buildings and weatherizing homes to make them more energy-efficient.
That all sounds great! But asphalt and concrete exacerbate the climate crisis, and spending hundreds of billions of dollars to repair our crumbling roads and bridges is a scary proposition. Washington State needs to provide oversight.
The asphalt in roads is a semi-solid form of petroleum. It absorbs 90% of the sun’s radiation, contributes to rising temperatures, and is a major source of air pollution. Asphalt emissions form organic aerosol in the atmosphere and tiny particles called PM2.5 which are one of the most dangerous types of air pollution for human health. Climate change causes higher temperatures which trigger more emissions.
Washington’s political subdivisions should do what Los Angeles and Phoenix do -– spray asphalt streets with CoolSeal, a rubberized asphalt emulsion which makes them more reflective and reduces the amount of trapped heat. It’s not a green solution. But the air pollution, greenhouse gas emissions, and water quality depletion caused by asphalt “heat islands” are mitigated by 10 to 15-degree cooler streets.
The Ash Grove cement plant generates a disproportionate 10% of Seattle’s greenhouse gas emissions. The chemical reaction that turns limestone into Portland cement releases CO2. Heating the kilns to 2,500°F to make that happen is the other half of its carbon footprint.
Washington needs more stringent clean air standards — ones that will force manufacturers and users to make/use green concrete which produces less carbon dioxide and is more durable than Portland cement. Green concrete incorporates at least one form of recycled materials in its components – including used concrete, quarry and mining waste, slag, burnt clay, power plant waste, combustor ash, saw dust, foundry sand, and waste glass. CO2 can also be injected into the concrete and trapped there.
A state green infrastructure component could be to stop or limit the use of concrete for schools and other public structures, as well as private homes, large residential and commercial buildings, etc. We could promote the use of compressed-earth bricks, hempcrete (biocomposite of hemp fibers and lime), or ferrock which is made from waste steel dust and silica from ground up glass. It’s five times stronger than concrete and rather than emitting CO2 as it dries, it absorbs and binds it.
Good old-fashioned timber also stores carbon dioxide, and that’s the best alternative for the Evergreen State. Everyone should be encouraging our state legislators to promote the use of the newer, cross-laminated timber grown and manufactured in Washington.