The California Cement Battle


The Sierra Club Released a Report Attacking California Cement Plants, But The Cement Industry Hit Back.

The Sierra Club California claims that California’s cement plants have higher emissions per ton of cement than similar facilities in China, India and other major cement-producing regions.

The Coalition for Sustainable Cement Manufacturing & Environment (CSCME) states that the Sierra Club report “paints an inaccurate and intentionally misleading picture of the California cement industry.”

CemexSo went the opening volley of a new war against the cement industry.

“There are a lot of things the cement industry can do to reduce its energy and process emissions, but few, if any, of California’s cement factories have undertaken any of these measures,” said Ali Hasanbeigi, the principal author of the Sierra Club report and CEO at Global Efficiency Intelligence, an international energy and climate technology consulting firm. “This study benchmarked California’s cement factories against their peers, and the results are not flattering.”

In “California Cement Industry: Failing the Climate Challenge,” Hasanbeigi and co-author Cecilia Springer recommend various options to help the state’s cement industry reduce energy use and GHG emissions. These include: investments in more energy efficiency processes; fuel switching; clinker substitution; use of alternative materials (e.g. engineered wood and high-performance polymers); and carbon capture, utilization and storage (CCUS).

CSCME provided the following rebuttal:

  • The California cement industry has significantly reduced its carbon footprint, while greenhouse gas (GHG) emissions from other cement industries, such as China’s, have grown exponentially (20 percent decrease in California between 2000 and 2015 versus China’s increase of more than 200 percent over the same time frame).
  • The California cement industry is just as carbon efficient as other high-performing cement industries when measured on an apples-to-apples basis.
  • Locally produced cement is the most environmentally responsible option for meeting California’s needs for durable and resilient infrastructure.
  • There is more work to do, and policymakers have real opportunities to unlock and accelerate further GHG savings throughout the cement-concrete supply chain.

The full gist of the Sierra Club’s argument is as follows:

Cement production is one of the most energy-intensive and highest carbon dioxide (CO2) emitting manufacturing processes in the world: On its own, the cement industry accounts for more than 5 percent of global anthropogenic CO2 emissions.

But not all cement is made equal. The cleanest cement factories can emit as little as half the pollution as their dirtiest counterparts. New developments in the cement and concrete sector are driving additional pollution reductions through new materials, enhanced and more effcient processes, and other low-carbon innovations.

The findings of this report show that California’s cement industry is not yet a part of the transition to a low-carbon cement and concrete sector. The state’s cement factories are the largest consumers of coal and petroleum coke in California; in fact, California’s cement factories have higher emissions per ton of cement than similar factories in China, India, and other major cement-producing regions.

California’s aging and ineffcient cement production facilities are substantially dirtier than new facilities in countries like China and India. The opportunity to clean up California’s cement industry is significant.

California’s cement factories are the largest consumers of coal in the state. California is the second-largest cement producing state in the United States after Texas.

California’s nine cement plants together produced about 10 million metric tonnes (Mt) of cement and emitted 7.9 Mt of CO2 pollution in 2015. More than 70 percent of the energy used in California’s cement industry is coal and petroleum coke, which are two of the most air polluting fossil fuels. California’s cement industry used around 34.28 petajoules (PJ– 1015 joules) of fuel, which includes more than 900 kilotonnes (kt) of coal and petroleum coke, and 1,340 gigawatt hours (GWh) of electricity in 2015.

  • The 900 kt of coal and petroleum coke is the equivalent of 7,500 railcars full of these fossil fuels.
  • The 1,340 GWh of electricity use is equal to the average monthly electricity consumption of around 2.3 million California households.

Around 60 percent of the total CO2 emissions from California’s cement industry are process-related emissions from the conversion of limestone to clinker; the remaining 40 percent are energy-related emissions from fuel and electricity consumption

CSCME Disagrees

“A recent paper commissioned by Sierra Club California and authored by Global Efficiency Intelligence paints an inaccurate and intentionally misleading picture of the California cement industry,” CSCME stated. “The paper’s sensational claims that the California cement industry is ‘failing the climate challenge’ and is ‘substantially dirtier’ than cement industries in other nations, including China, are absurd and incompatible with the facts, including many of those presented in the paper itself.”

The California Cement Industry Has Significantly Reduced Its GHG Emissions Since 2000.

Despite the Sierra Club paper’s sensational claim that the California cement industry is “failing the climate challenge,” the truth is that the industry has substantially reduced its GHG emissions.

For instance, as noted in the paper, the California cement industry decreased CO2 emissions by 2 million metric tons (Mt) from 2000 to 2015. This is in sharp contrast to the Chinese cement industry, which increased its CO2 emissions by roughly 700 million Mt over the same timeframe.

As also noted in the paper, the reduction in CO2 emissions in the California cement industry was due to a combination of factors, including:

  • A 17 percent reduction in fuel-related CO2 emissions intensity due to investments in energy efficiency and greater use of lower-carbon fuels.
  • A 13 percent reduction in cement output, which roughly halved during the Great Recession and still remains below pre-recession levels.
  • A 10 percent reduction in electricity-related CO2 emissions intensity due to investments in electricity efficiency and the decarbonization of the California electricity grid.

According to the authors, these trends resulted in a 20 percent decrease in the California cement industry’s GHG emissions between 2000 and 2015. In contrast, GHG emissions in the Chinese cement industry increased by more than 200 percent over the same timeframe, which the paper neglects to mention in its efforts to position the Chinese cement industry as a model of environmental performance.

The California cement industry’s achievements are impressive by almost any standard, not just in comparison to China. For instance, the 20 percent decrease in the California cement industry’s emissions is three times greater than the 6.4 percent reduction in statewide GHG emissions over the same timeframe.

Given these facts, the California cement industry’s performance in recent years is best described as an environmental policy trifecta – reduction of GHG emissions, improvement in energy efficiency and greater use of lower-carbon fuels. All of this was accomplished while minimizing GHG emissions leakage, recovering from one of the most severe downturns in the industry’s history, and complying with California’s other stringent environmental regulations.

The California Cement Industry Is Just As Carbon Efficient As Other High-Performing Cement Industries When Compared On An Apples-To-Apples Basis.

The paper’s conclusion that the California cement industry is “substantially dirtier” than cement industries in other nations is based exclusively on the results of its so-called “benchmarking” analysis. Although the benchmarking analysis is flawed in several respects, the authors’ most egregious error is in manufacturing “apples-to-oranges” comparisons.

Specifically, the authors measure CO2 intensity on a per-ton-of-cement basis, which introduces an extreme bias against the California cement industry. To understand the nature of this bias, note that the primary purpose of a cement plant is to produce clinker, which is the key binding agent in cement and accounts for the vast majority of GHG emissions in the concrete supply chain. Various types of cement are then created by blending clinker with other substances, including gypsum, limestone and supplementary cementitious materials (SCMs).

The addition of these other substances effectively “dilutes” the amount of clinker, which reduces the amount of GHGs per ton of cement without any change in the environmental performance of the plant. This bias is compounded by the fact that SCM blending can happen at either the cement plant or the ready-mix concrete facility. In fact, in most countries, it is customary to add SCMs at the cement plant. As the paper states, however, “in the United States (including California), most SCMs are added at ready-mixed concrete facilities.”

The Sierra Club paper acknowledges this important distinction in several places, but then inexplicably ignores it when conducting the benchmarking analysis. By conducting their benchmarking exercise on a cement basis, the authors virtually ensure that the California cement industry will appear to be worse than all other cement industries.

In other words, the result is more of a “feature” of the analysis than a “finding” from it. Instead, the authors should have measured CO2 intensity on a per-ton-of-clinker basis, which provides a more objective measure for comparing carbon efficiency across industries. CSCME is confident that an apples-to-apples comparison that corrects for this bias would show that the Sierra Club’s analysis is highly misleading and that the California cement industry is just as carbon efficient as other high-performing cement industries around the world.

Locally Produced Cement Is The Most Environmentally Responsible Option For Meeting California’s Needs For Durable And Resilient Infrastructure.

In its attempt to paint a distorted picture of the California cement industry, the Sierra Club paper neglects to point out that locally produced cement is the most environmentally responsible option for meeting the state’s infrastructure needs due to:

  • The stringent environmental regulations under which California plants operate.
  • The GHG emissions associated with transporting cement from other markets.

First, the California cement industry is subject to some of the most stringent local, state, and federal regulations in the world with respect to toxic and criteria air emissions (e.g., mercury, particulate matter, NOx, SO2).

In contrast, the Chinese cement industry releases toxic and criteria air emissions on a breathtaking scale. As noted in a 2017 study co-authored by the principal author of the Sierra Club paper: “Consistent with the Chinese cement industry’s large production volume, total carbon dioxide (CO2) emissions from the industry are very high, as are associated air pollutant emissions, including sulfur dioxide (SO2), nitrogen oxides (NOx), carbon monoxide (CO), and particulate matter (PM). These emissions cause significant regional and global environmental problems. The cement industry is the largest source of PM emissions in China, accounting for 40 percent of PM emissions from all industrial sources and 27 percent of total national PM emissions.”

Second, if California does not source its cement locally then it will most likely import it from countries that can logistically and economically access the coastal market, particularly China. This involves not only producing the cement, but transporting it from a plant to a port, loading it onto a ship, sending it halfway around the world using bunker fuel, unloading it at a port in California, and then transporting it in diesel-powered trucks through California’s port neighborhoods and other communities before it eventually reaches the end customer.

This series of activities results in significant GHG emissions that are likely to outweigh any insignificant differences in the GHG emissions associated with producing clinker. In short, the Sierra Club paper sidesteps the most important question, which is: How does California source the cement it needs in the most environmentally responsible manner?

Instead, the paper focuses on making politically motivated arguments that erroneously paint the Chinese cement industry as a model of environmental performance and that ignore the environmental and climate change benefits of locally sourced cement. Policymakers should take action to ensure that the cement that California consumes meets the state’s stringent environmental standards and to avoid the additional GHG emissions associated with importing cement from China and other distant locations.

There Are Significant Barriers To Increasing The Use Of Scms In California In An Environmentally Responsible Manner.

The Sierra Club paper argues that, when measured on a per-ton-of-cement basis, the California cement industry has a higher emissions intensity than China’s (as well as most others outside of California), primarily due to differences in the use of SCMs.

The paper notes that SCMs are typically added at cement plants in most countries but are added at ready-mix concrete facilities in the United States, including California. However, the paper fails to mention that there are also substantial barriers to increasing the use of SCMs in California, regardless of whether blending takes place at the cement plant or concrete facility.

The primary barrier is the lack of a steady local supply of SCMs such as fly ash and slag, which are waste products from coal-fired electric power and steel manufacturing, respectively. Given that California does not have coal-fired power generation or steel manufacturing, the California cement industry must import SCMs from other regions.

In contrast, the Chinese cement industry has access to a large, local and steady supply of SCMs due to the country’s heavy reliance on coal-fired electricity and steel manufacturing. As a result of these market conditions, efforts to require or incentivize the increased use of SCMs in California could actually increase global GHG emissions.

Given that SCMs are not produced locally in California and are highly utilized in areas where they are produced, increasing demand in California would curb their use elsewhere. This artificial “reshuffling” of materials could create an illusory benefit, with GHG decreases in California being offset by increases in other areas. Diverting cement substitutes to California from distant locations will also increase transportation-related emissions, which means that this artificial reshuffling of supply could, on net, actually increase global GHG emissions.

Policymakers Have An Opportunity To Unlock And Accelerate Additional GHG Emissions Savings By Facilitating The Adoption Of Portland-Limestone Cement (PLC) In California.

The California cement industry, unlike other cement industries, has limited ability to reduce GHG emissions through the blending of SCMs at the plant. It could, however, significantly reduce GHG emissions if the state adopts standards that permit the use of Portland-Limestone Cement (PLC), which would allow an additional 10 percent of limestone to be added to the final product.

CalPortlandThe use of PLC in California would advance the state’s environmental goals, including the reduction of GHG emissions in the cement industry, while providing comparable performance. PLC has been used in Europe for more than 40 years and in Canada for over a decade.

In the United States, a majority of states have accepted PLC standards, which include testing requirements to classify cement for use in high sulfate soil regions, such as California.

Given the size of the California Department of Transportation (Caltrans) and the fact that many other entities use its standards, the agency’s approval of these standards is an essential first step toward producing and using PLC throughout the state.

Permitting the use of PLC is the quickest and most cost-effective pathway to reducing GHG emissions in the California cement industry. It is estimated that, given production dynamics, the widespread use of PLC could reduce the cement industry’s GHG emissions by as much as 9 percent.


The California cement industry is proud of the progress that it has made in decreasing its GHG emissions, and we look forward to engaging with policymakers, regulators, and other interested stakeholders to find new ways to reduce the industry’s carbon footprint while minimizing the risk of emissions leakage.

However, a constructive conversation about how the industry can continue to contribute to California’s climate change objectives cannot be based on sensational claims and intentionally misleading analysis. Rather, it must be rooted in a complete, accurate and even-handed accounting of the facts, as well as full consideration of the industry’s unique circumstances.

The Coalition for Sustainable Cement Manufacturing & Environment comprises all the Portland Cement manufacturers operating in California.

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