Sustainable Development Goals

The United Nations’ Sustainable Development Goals (SDGs) promote equality. They also promote economic growth together with the preservation of the Earth’s ecosystem. The goals are admirable. Are they achievable? Let’s consider.

People who are rich consciously act to maintain their status. Certainly they’d be OK with everyone else being rich as long as they remained rich. This all inclusiveness wouldn’t be likely for two reasons. One, many people don’t care to be materially wealthy. Two, the Earth’s ecosystem can’t support an infinite number of wealthy people. Thus, we expect to always have a wealth disparity between people.

People who are poor don’t want to be poor. They may not realize that they are poor, as with some indigenous people who maintain a hunter/gatherer lifestyle. But, there’s a global expectation on child survivability, education and security. These expectations promote fairness. Achieving this requires the continual application of significant resources, such as energy. However, the Earth’s ecosystem can’t support the advancement of an infinite number of poor people.

Last, our current economic system could enable all the poor to be rich. The system enables us to transfer resources to any location on Earth and perhaps even off of Earth. But the Earth has finite resources. Also, our utilization of resources, such as fossil fuels, comes with detrimental pollution. Hence, while the system is capable, the result is unattainable.

Yet, the SDGs are our only blueprint for the future. And it is a good blueprint. So, what’s the best future? Do we control the number of rich? How many poor can the Earth accommodate? How do we preserve the Earth’s ecosystem while continually drawing down its capital? Perhaps most of all, what degree of achievement is optimal for each goal?
Chipping sparrow

Cement and Concrete

People seem to have a reluctant relationship with Earth’s natural world. We know that nature provides us with our necessary food. But most of us buy it in shops. And, with most of us living in cities, even our homes and workplaces are removed from nature. For these, concrete is the most effective separator. It’s a human invented material that is the foundation for most of our civilization.

Concrete results from mixing cement with water and with a suitable filler such as sand or gravel. Its use in the Roman era Pantheon demonstrates its durability. Its longevity can be further enhanced as we use rubble from destroyed concrete structures as filler for new concrete structures. However, cement can’t be re-used. New concrete requires new cement. And cement is costly.

Let’s scale the cost. Annually we produce over 4×109 tonnes of cement, equivalent to the cement for about 1000 dams the size of the 3 Gorges Dam. This amount is to remain constant to well past 2050. Its production calls for an annual expenditure of 3.5GJoules of energy per tonne. This amounts to an allocation of 1.4×1019Joules of energy annually, about 3% of total energy consumption. As most of the energy comes from fossil fuels then there’s resulting pollution at a rate of 0.54t of CO2 per tonne of cement, about 8% of global CO2 emissions. Because of this, cement is a significant parameter when modeling future climate change. Over history, humans have used about 128×109 tonnes of cement to enable living apart from nature, which is almost a thousand times greater than the weight of all humans. Concrete is costly both in energy consumption and pollution emission.

Concrete separates us from nature. And estimates are that we will continue this separation for decades to come. Should we continue to separate ourselves from the ecosystem? Or are you willing to fight this apparent primal urge to treat nature as a threat? For a prosperous future, we recommend you look for ways to live with nature rather than apart.