PODCAST: ネット通訳担当tensaimon 20: セメントの環境影響 Cement’s environmental effects



The Outline: Are we stuck with cement?


まとめ Summary:

Earlier this year, Sara Law of the Carbon Disclosure Project raised her hand at a conference in New York to discuss opportunities for investing in low-carbon infrastructure to address climate change.

She politely asked the panel whether they knew how much cement each project might require.

The panel members shifted uncomfortably in their seats and chuckled; no one jumped in immediately to respond.

Law didn’t mean to embarrass her peers. But her question unraveled some of the forced optimism that has hung around climate conferences of late.

Environmental academics and activists have been joined onstage by financiers with promises of investment opportunities in the ongoing transition to a more sustainable economy. renewable energy projects; new energy grids; updates to piped water systems.

Governments and environmentally minded investors luxuriate in these types of projects because they can help prevent human-caused, or anthropogenic, global warming without sacrificing economic growth.

The problem is that many of these projects require concrete. A lot of concrete.

the Carbon Disclosure Project …recently released a report…warning the cement industry — that “in its current form, it will not be compatible with” any nation’s commitment in the Paris agreement.

Cement is perhaps the most essential ingredient in an economy’s growth. The incredible scale of its importance was illuminated in the historian Vaclav Smil’s book, Making the Modern World: Materials and Dematerialization, which told of Chinese companies using more cement between 2011 and 2013 than the U.S. did throughout the entire 20th century.

According to the report, the cement industry is the second-largest industrial emitter of carbon after the steel industry….it is responsible for more than a third of the world’s carbon emissions.

But unlike the transportation sector, in which a new type of fuel can dramatically decrease the sector’s pollutants, cement’s problem is, well, cemented in…

For cement companies, lowering emissions would mean either developing a whole new material or investing in carbon-capture systems, a technology that can capture and store the carbon dioxide emitted by an industrial process.

Yet the CDP found the industry to be unwilling or unable to finance the research required to develop a low-cost, low-carbon alternative to cement.

The report chalks up the industry’s intransigence to a business model that, economically at least, is doing quite well. Infrastructure projects need concrete and cement, regardless whether they’re for a low-carbon economy.

The average wind turbine, for example, needs about … 57 trucks worth of concrete. The turbine will produce…. enough electricity… to power 2,400 U.S. homes for one month.

We desperately need these infrastructure projects to transition to a carbon-neutral world, but in doing so we will have to emit a massive amount of carbon.

The article talks about a low-carbon alternative developed at MIT, but it is still experimental, and the cement industry has not yet seriously engaged with the problem: Why introduce a new product if everyone is already buying your old one?

But its conclusions savagely lay bare the fallacy that, at our current state, we can solely use large scale infrastructure to develop ourselves out of the problem of anthropocentric global warming.

Hey Simon what do you think? 私に一コメントいわせていただければ・・・

It is possible that this is “money well spent” – that we should emit the carbon in concrete to make a world that emits zero carbon.

However when we talk about “investment” we are talking about people and companies spending money because they expect to get more money back.

I worry that companies are motivated by profit not by making a sustainable world.

This leads to the problem of “de-coupling” – having economic growth without environmental harm - many people, including Saitou Kouhei in his book 人新世の「資本論」think this is impossible – certainly there is zero evidence that it can be done.

I think a better solution is a low-energy world: instead of building more big infrastructure projects, we should be reducing how much energy we use:

  1. living in 15-minute neighborhoods where we don’t need to travel large distances every day
  2. making these neighborhoods self-sufficient: growing food forests, generating electricity, collecting and processing water, running small businesses making clothes, tools etc
  3. riding bicycles to get around, (bicycles need much smaller roads than cars, as described in this article: : less concrete!) and
  4. growing trees for shade to keep cool instead of running aircon.

I think these are much better solutions to the question of how to live sustainably…but of course there is no massive profit in these ideas….

Hey Listeners what do you think? どうぞ自分の”一コメント”をメールで読ませてください

Do you know about the huge carbon footprint of concrete?

Do you think we need these projects for a sustainable world, or do you think they are intended to generate profit?

What do you think of the idea of creating a low-energy society instead?

参考のリンク Related Links

A book about all the materials used in making our modern world:


The documentary “Planet of the Humans” questions large infrastructure projects:

We should live in cities where we can live our daily lives within 15 minutes: https://www.15minutecity.com/

A video about an urban food forest project:

Smaller vehicles can mean we can maintain smaller roads:


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