Take a quick drive south to Klang Valley, have a glimpse of Batu Caves, and turn around back to Kinta, slowing down as you reach the outskirts of Ipoh. You will acquire a new ugly perspective of the city and it should bring tears flowing down. The limestone hills are no longer majestic looking; instead they resemble scorched faces exposing their raw underside — bare rock shorn of all greenery.
In decades to come, Ipohites will be singing: “Take me back to the green hills, the green hills of ol’ Kinta, where the limestone’s so cool, and clear water fills the pool.” As they sing these heartbreaking lyrics to the tune of Calamity Jane’s Black Hills of Dakota, your grandchildren will have to imagine the lost world of highland greenery gone with the cement and the concrete.
The limestone quarrying industry that began in the 1970s is one of the biggest contributors to Perak’s economy, and a supplier of base materials for building and construction activities throughout Malaysia. The most important use of limestone is in the production of cement, an essential ingredient for concrete that is daily poured to serve as building foundations, structural beams, columns, walls, sidewalks, and even as roads.
Limestone cement is among the highest contributors to global warming, accounting for 3 gigatonnes or 8% of the worldwide human-induced carbon dioxide emissions each year. Nearly one tonne of CO2 is released for every tonne of fresh cement. As The Economist weekly quipped sardonically in an issue last November: “If the cement industry were a country it would be the third-largest emitter in the world, after China and America.”
A week ago, the group managing director of one of Malaysia’s top 10 property developers lamented that there is no known substitute for cement. We don’t have the technology today to achieve net-zero emissions, he said at a sustainability summit. But the news is already out that the technology to replace limestone as the base material for cement has been discovered, and it turns out to be as simple as going for a pee.
What is limestone? Its chemical composition is CaCO3 or calcium carbonate (calcium, carbon, oxygen). That’s the stuff of which bones, skin, nails, claws, and shells of living organisms are made. A limestone hill is a burial mound of long-dead sea creatures — the remains of seashells, oyster shells, snail shells, eggshells, coral, and plankton. If you dig at a limestone hill for the money, you’re a tomb raider.
Just three months ago, research engineers in the United States successfully used plankton to replace quarried limestone as a source of calcium, carbon and oxygen for cement. The process did not release any CO2 into the atmosphere. Two months before that, research scientists in Singapore made biocement by using urine and industrial waste to obtain calcium, carbon and oxygen.
Calcium is the earth’s 5th most abundant element. Every year a million tonnes of calcium-rich agricultural and industrial waste are generated around the globe. There is also plenty of inorganic calcium-rich waste such as gypsum and sludge. Instead of dumping waste products, they should be processed for the recovery of calcium carbonate and calcium oxide particles by physical and chemical methods.
Plastic, when subjected to extreme heat, can also be broken down to its original chemical building blocks that are primarily carbon, oxygen, and hydrogen. So plastics can be turned into cement with the addition of calcium. Some engineers and inventors in Kenya earlier this year managed to convert mountains of discarded plastic materials into bricks that are stronger, cheaper and lighter than concrete.
They did it by shredding the plastic, mixing it with sand, and subjecting the mixture to extreme heat in the presence of a chemical catalyst to produce a cement-like sludge. What is sand? It is 26% calcium. So these entrepreneurs obtained the necessary calcium, carbon, and oxygen by mixing plastics and sand. But as calcium is in plentiful supply, you can find other sources besides sand.
So what excuse is there for Malaysia to lag behind? According to the Real Estate and Housing Developers’ Association (Rehda), the price of cement rose 19% during the first half of this year. There is hence a cost-saving incentive for the property industry, even if saving the limestone hills isn’t top of the agenda.
What Rehda should do is partner with some local universities to drive cutting-edge technological innovation to develop eco-cement on an industrial scale. Any university should be keen on such a project, as the job of a university isn’t just to produce unemployable graduates but to conduct useful R & D.
If eco-cement is too avant-garde, Rehda can fall back on tradition and revisit the old kampung house. Trending in Europe and America is the use of mass-timber, even for high-rises. The Mjostarnet mixed-use building in Norway is a massive block of wood 85 metres tall, and the Ascent in Milwaukee, USA, which opened three months ago, stands at 86.6 metres tall. Made of cross-laminated timber, Ascent took just two years to finish.
The Ascent and Mjostarnet will be dwarfed by the Chicago River Beech Tower. Standing 244 metres tall, the proposed 80-storey Beech Tower will use no steel or concrete. These three buildings ought to excite Rehda because steel prices have risen 38% and concrete 16%.
Rehda can press the State Governments such as Perak for idle lallang and bush plots to be developed into commercial mass-timber farms. These are farms without cows and veggies, just quick-growing trees picked for their housing suitability and cloned. The logs are processed into engineered timber that has steel-like strength and yet is 80% lighter.
If you construct a 4-storey building using steel, cement, and concrete, you will generate 500 tonnes of carbon dioxide emissions adding to the global heat that compels you to air-condition even the toilets in this 4-storey building. But if you use mass-timber, the amount of wood locks up 540 tonnes of C02. You deserve a climate warrior badge for removing that much heat-inducing C02 from the air.
Mass-timber farms also provide the answer to jungle logging. Once you cut off the demand for natural forest timber, loggers will be left dangling on a branch where you can hang them using thick vines from the same tree.
What about the quarrymen displaced by green technology? Quarrymen can be retrained to love the green instead of the grey. If plastics can be remoulded, human beings and their industries can’t? There is no excuse for delaying action on climate change.
Property developers and homebuyers don’t have to choose between a hill and a house. But nature will force us to abandon our houses if we choose to remain unconcerned despite the floods and tsunamis.
Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the official policy or position of Ipoh Echo