Cement, Steel, and Natural Gas Are Major Greenhouse Gas Emitters, Too

Taken together, cement production, iron- and steelmaking, and natural-gas leaks rival transportation in their effects on climate

2 min read
Opening illustration

While our June 2018 special report, “Blueprints for a Miracle,” covers many of the key sources of greenhouse gases and strategies for their mitigation, the report does not address three rather substantial sources. The production of cement—the primary component in concrete—accounts for about 5 percent of global carbon dioxide emissions. Iron- and steelmaking contributes a similar amount [PDF]. The use of natural gas (methane) in place of oil or coal reduces carbon emissions, but methane itself is a potent greenhouse gas, and a considerable quantity leaks into the atmosphere during its production and transport. Estimates suggest that such leaks are comparable in their climate effect to those of cement production or iron- and steelmaking. Here’s a quick take on what might be done to limit these three sources.

  • Cement Production

    img Illustration: James Provost

    The Problem: Copious quantities of CO2 are emitted during the conversion of limestone (CaCO3) to lime (CaO), a key ingredient in cement. That conversion is done in a kiln [yellow], which is heated by burning fossil fuels, a process that emits still more CO2.

    Low-Tech Solution: Use less lime and replace it with fly ash, a by-product of burning coal. The ancient Romans did something similar, using volcanic ash in their pozzolana concrete, examples of which have lasted thousands of years.

    High-Tech Solution: Add liquefied CO2 captured from power plants to wet concrete, where it will form tiny crystals of calcium carbonate, effectively sequestering the carbon and keeping it out of the atmosphere indefinitely.

  • Iron- and Steelmaking

    img Illustration: James Provost

    The Problem: Converting iron ore to iron—the principal component of steel—requires coal, which serves as a reducing agent and provides the necessary heat as it is burned in a blast furnace [yellow]. That combustion releases large amounts of CO2 into the atmosphere.

    Low-Tech Solution: The simplest way to reduce these emissions is to recycle more steel, thus diminishing the need to mine iron ore and convert it to iron. Steel is often recycled now, but even more could be reused.

    High-Tech Solution: If sufficient renewably sourced electricity is available, iron could be extracted from iron ore by electrolysis, thereby avoiding carbon emissions. Electrolysis is similarly used today at aluminum smelters.

  • Natural-Gas Leaks

    img Illustration: James Provost

    The Problem: The infrastructure used in the production and transport of natural gas is prone to leaking if it is not properly maintained.

    Low-Tech Solution: The natural-gas industry could be more diligent in its routine checks for leaks in the equipment it uses, even in settings where such gas leaks don’t create a risk of explosion.

    High-Tech Solution: Laser-based systems can be used to monitor for leaks at a distance. One company pursuing this technology is LongPath Technologies, a spinoff from the University of Colorado, Boulder.

The Conversation (0)

Revealed: Jupiter’s Secret Power Source

Auroras explain why the gas giant is so hot

4 min read
Image captioned 25 January 2017 of Jupiter taken by the Keck telescope revealing an aurora at the planet’s poles and wide swaths of heat radiating downward into the planet’s temperate latitudes

For all its other problems, Earth is lucky. Warmed mostly by the sun, 150 million km away, shielded by a thin but protective atmosphere, the temperature at the surface averages 14 to 15 degrees Celsius—a good number to support liquid oceans and a riot of carbon-based life.

Jupiter is a different story. Its upper atmosphere (Jupiter has no solid surface) has a temperature closer to what you'd find on Venus than on some of Jupiter's own moons. As will be seen below, planetary scientists have for decades puzzled over why this planet so far from the sun is so inexplicably warm. In 2021, however, the solution to the mystery may at last have been found.

Keep Reading ↓ Show less

Paying Tribute to Former IEEE President Richard Gowen

His research for NASA looked at the effects space had on astronauts

4 min read

Richard Gowen, 1984 IEEE president, died on 12 November at the age of 86.

An active volunteer who held many high-level positions throughout the organization, Gowen was president of the IEEE Foundation from 2005 to 2011 and two years later was appointed as president emeritus of the IEEE Foundation. He was also past chair of the IEEE History Committee.

Keep Reading ↓ Show less

Transforming 55,000+ substations into independent micro data centers addresses the most pressing distribution, security and cost challenges plaguing the U.S. power grid. Learn how virtualization delivers a holistic solution to modernize and expand the Grid with the capacity, protection and reliability needed to keep power flowing smoothly.


Keep Reading ↓ Show less