The outer limits: Future economic growth in the face of diminishing resources

The 1972 book "The Limits to Growth" states that the Earth's resources are finite and probably cannot support current rates of economic and population growth to the end of the 21st century. The message still deserves our attention 50 years after it was derided by economists.

Thomas Murphy is a professor of physics at the University of California San Diego. His assessment appeared in a paper.

Murphy became interested in planetary limits after he taught a class on energy and the environment. The students studied the physics of energy and how to calculate energy demand and resources. Murphy realized that the issues of resource and energy consumption were more serious than he had thought.

Murphy stated that this is something not enough people are paying attention to. What do you think life will look like after resources are exhausted? How are we going to get people to take this seriously?

It can be hard to imagine a time when humankind will have to adjust its way of living to fit in with the finite resources of the Earth.

Murphy wrote a book about energy and human ambition on a finite planet.

The Earth has never hosted 8 billion humans before. Projections can't be based on the past. This is not something that has ever been done before.

Murphy used our historical growth rate of a factor of ten each century to show the point. If humans consume 18 TW of energy, by the year 2200 it will be 100 TW and so on. We would surpass the solar power incident on Earth in 400 years and the output of the Sun in 1,300 years.

The amount of waste heat produced would accelerate and cause the temperature to soar if the same growth rate is used. The Earth's surface would reach the boiling point within 400 years.

Murphy made it clear that the extrapolation of energy consumption and waste heat is not realistic. Our growth can't continue indefinitely into the future. If the progression is to be believed, the period of excessive energy consumption on Earth will be short-lived compared to the lifespan of civilization.

Even the most optimistic of economists will concede that there is a limit to the Earth's physical resources, but many insist that this won't affect economic growth because money will be "decoupled" from physical resources, thus able to grow without being constrained by the depletion of fossil fuels or

Money doesn't have to obey the laws of physics or that we can sustain economic growth through innovation, according to Murphy. Limits are not impervious to those things. Physical resources are needed to build and run those computers in the virtual realm. That's what we're seeing for the huge amount of energy it consumes.

Murphy concedes that many economic activities do not require intense use of physical resources, for example, work in the legal and financial sectors, for example, but are not fabrication of concrete and steel. It is easy to assume that the proportion of decoupled activities will increase, but at some point the demand for physical resources will no longer be needed. Humans will always need sustenance.

Murphy stated that they don't see economic growth for what it is. We don't see it because we don't want to have to. We don't have to address the issue of reallocating present resources more equitable because of continued growth.

There is a double-edged sword to economic growth. People may be lifted out of poverty if the economy grows. As the standard of living increases, the higher resource demands overtax the planet's capacity and threaten to remove the benefits.

Murphy says a fundamental shift in how we think of ourselves as a species is needed to solve the problem. Our relationship with the planet needs to be changed. Humility is needed to accept that we don't own the Earth. How do you convince someone that something they've never seen before is worth sacrificing their lives for? I hope that we can plant some seeds that will help us make better decisions down the road.