Banned for 90 Years, This Building Material Returns With 15x Concrete's Insulation and Centuries of CO₂ Storage

[hunter]

10. Calcium carbonate stone is heated to make lime. This emits carbon dioxide.

The heat source is usually a fossil fuel which also emits carbon dioxide.

As the lime reacts with carbon dioxide from the air, as the finished product cures, it absorbs only a fraction of the carbon dioxide that was emitted in making it.

Lime is not a "net zero" product. Neither is hemp.

Refurbishing existing structures usually has a smaller environmental impact than new construction. In an ideal world we'd be rebuilding our cities, turning them into attractive affordable places where car ownership is unnecessary -- office space turned into apartments, etc.

The "back to the land" Mother Earth News sort of environmentalism was never good for the environment.

I think the harshest lesson from Chornobyl is that humans going about their ordinary business do more damage to the natural environment than radioactive fallout from the worst possible sort of nuclear power plant accident.

Other than plastics used for decoration or insulation, I think modern construction materials are hard to beat -- concrete, concrete block, wood or metal framing, rockwool, and gypsum board. If concrete structures are allowed to stand for centuries and repurposed over the decades with gypsum board and wood or metal framing the environmental footprint can be smaller than that of structures that are torn completely down and hauled off to the landfill after a few decades use.

Here's another example of hemp (in the form of canvas) being used as a construction material: