Climate killer cement: the foundation of the world becomes an enemy

The world would be different without cement.

With their "Opus Caementitium", a mixture of quarry stone, clay, volcanic ash, sand and lime, the Romans created structures of permanent size two thousand years ago: The "cement" dome of the Pantheon was considered the largest self-supporting one until the beginning of the twentieth century Roof construction at all.

The foundations of the modern world are still poured from cement and its watery brother concrete.

Until climate change, hardly anyone was interested in that.

But now cement has become an enemy, a climate killer.

In fact, the cement industry causes between seven and eight percent of all greenhouse gases.

HeidelbergCement alone emits as much as Austria.

Cement should therefore play an important role in the fight against climate change.

However, it is not at all clear which one it is.

Because it doesn't work without cement.

A climate-friendly production is not possible

What that means in reality can currently be observed in Sweden.

There are only two cement plants there, both of which are owned by HeidelbergCement.

The larger one, on Gotland, covers two thirds of the cement requirement.

Environmental groups are calling for the plant's approval to be withdrawn.

Not because of its greenhouse gases, but because limestone mining endangers groundwater. 

The company has announced production cuts due to the uncertain continued operation.

A production stop would, however, have serious consequences, including an economic crisis.

Despite court rulings to the contrary, the government should therefore continue to approve the operation.

Not only is there no alternative to cement.

Nor can it be produced without releasing carbon dioxide.

With cement, chemistry stands in the way of climate-friendly production, as is the case with steel.

When lime is burned, the carbon dioxide bound in it is released.

These “unavoidable process-related emissions” make up two thirds of all cement emissions - far more than any other industrial product.

Industry has turned the simple screws.

The furnace firing was changed, the proportion of clinker in the cement was reduced, and clay or blast furnace slag was added instead.

From 100 percent in the primary product Portland cement, the proportion of clinker has in some cases fallen to 50 percent.

Much less is not possible.

The processes are exhausted.

Last lifeline CCS?

In order to become climate-neutral, the cement industry only has CCS - the separation, storage or further processing of carbon dioxide. Despite the enormous investments, technology is the last lifeline for many energy-intensive industries. But even though the Intergovernmental Panel on Climate Change is pushing CCS, there are still reservations. Even in Germany, the paradise of the energy transition, storage is de facto forbidden. The outgoing federal government has brought about little more than a research project. Nobody knows how and where ten million tons of carbon dioxide from German cement works will be transported from 2050 onwards.

The status quo does not suggest anything good. The companies outbid each other in announcement offensives, in fact they are playing for time. You can't even blame them. One industry alone cannot solve this problem. Heidelcement has only budgeted 500 million euros for its CCS projects over the next ten years. That's less than a year's maintenance budget. The group wants to build the world's first CO2-free cement plant in Gotland, of all places. With the support of the Swedish government, of course. So this government, which is now struggling to allay the concerns of the population. Those involved have planned ten years for approval and construction. Ten years!

Emissions trading has so far failed to achieve its goals, which is also part of this dreary reality.

Instead of building up pressure, the free certificates generated additional profits for the company.

The German cement industry's CO2 emissions have not fallen since 2005.

There is no way out of the dilemma in sight.

Today, the CCS wonder technology is little more than a simulation game on paper.

And emissions trading, if it finally works, will soon reach its limits with cement.

It will not lead to a further reduction in greenhouse gases because the laws of nature do not allow that.

But it will make cement and thus building more expensive.

Society has to know that, and it has to want it.

As I said, the world would be different without cement.