Carbon cycle

World population and our consumption habits are a significant factor in how much of the Earth's resources we use, which in turn relates to the carbon cycle. The following concepts help us understand this connection and how we can reduce our impact.

World Population & Ecological Footprint

The world population is simply the total number of people on Earth. The rapid growth of the human population, coupled with increasing consumption per person, puts a huge strain on the planet's resources. 

• Our ecological footprint is a measure of this strain. 
• It's an accounting tool that quantifies the amount of biologically productive land and sea area required to produce all the resources a person, a country, or humanity consumes and to absorb the waste, especially carbon emissions, they generate. 
• It's a way of asking, "How many Earths would we need if everyone lived like me?"

For example, a person in a developed country generally has a much larger ecological footprint than someone in a developing country because they consume more energy, food, and goods.

By measuring the Footprint of a population, individual, city, business, nation, or all of humanity, we can assess our pressure on the planet, which helps us manage our ecological assets more wisely and take personal and collective action in support of a world where humanity lives within the Earth's bounds.

Global Hectare & Planet Equivalent

A global hectare (gha) is the standard unit used to measure both the ecological footprint and the planet's biocapacity (the ability of ecosystems to regenerate what people demand from nature). It's a hectare of land with world-average biological productivity.

When we compare the total ecological footprint of humanity with the Earth's total biocapacity, we get a figure called the planet equivalent. Humanity's current ecological footprint is larger than the Earth's biocapacity, meaning we are using resources faster than the planet can regenerate them. This is often expressed as needing a certain number of "Earths" to sustain our current lifestyle. As of now, humanity is using the equivalent of more than 1.7 Earths worth of resources.

It's important to understand the difference between planet equivalent and Earth's age. The planet equivalent is a modern-day ecological measurement of resource consumption versus resource regeneration. In contrast, Earth's age is an estimate of how long the planet has existed, which is about 4.5 billion years. They are completely unrelated concepts, as one is a measure of human impact and the other is a measure of geological time.

Embodied Energy, CO2 Emissions & the Carbon Cycle

The carbon cycle is the natural process where carbon moves between the atmosphere, oceans, land, and living organisms. It's a delicate balance that is being disrupted by human activities, primarily through the burning of fossil fuels, which releases large amounts of carbon dioxide (CO2​) into the atmosphere.

The role of materials is a crucial factor in this disruption. Many materials we use, especially in construction, have a high amount of embodied energy—the total energy consumed by all the processes associated with a product's creation, from mining and manufacturing to transportation. This energy consumption directly leads to CO2​ emissions.

The production of cement, the key ingredient in concrete, is a major contributor to these emissions. It's responsible for about 8% of global CO2​ emissions. This is because the process of making cement, which involves heating limestone to very high temperatures, releases a lot of CO2​.

We can lower cement consumption and its associated emissions through two main strategies:

• Mechanization: Using advanced machinery and techniques in construction can lead to more efficient use of materials. For instance, using 3D printing or prefabrication can reduce waste and the amount of concrete needed for a structure.

• Admixtures: These are substances added to concrete to change its properties. Certain admixtures can make concrete stronger, allowing us to use less of it for the same structural integrity. They can also improve workability, making it possible to use less cement while maintaining quality. This reduces the amount of cement clinker needed, which is the most carbon-intensive part of cement production.

References:

https://www.youtube.com/watch?v=yhlg9txl7yM&ab_channel=TheEconomist