From Empty World to Full

WorldEcological Economics, Chapter 7 Review

“How do we explain the unwavering devotion to continuous economic growth by economists, policy makers, and the general public in the face of ecological and natural resource limits?”

The laws of thermodynamics ensure that there are limits to growth.

We must determine how close those limits are.

“Sustainable Economic Growth” is an Oxymoron

Exhaustion hardly seems imminent, we get regular reports of increasing stocks.

We can extract at any rate, scarcity of flow is the limiting issue.

Best estimate at current rates suggest probable stocks will be exhausted in about 40 years.

Energy Information Administration estimates that global demand will increase by 50% in the next 20 years.

Fossil Fuels

New Discoveries and Production have peaked, but consumption is still high.

A. HubbertCurve for OilDiscovery5 yearIntervals1912 – 1992

The actual peak

was in 1970

Fossil Fuels

Fossil Fuels

A. Hubert curve for oil production

Solar energy will require a great deal of time to be developed as a viable substitute for fossil fuels.

Without disrupting existing land use we could only meet 20-50% of our current energy needs in the US.

Food production in the US uses 3 times more oil energy than it provides in carbohydrate energy.

Using existing technology◦ Less fossil fuel = less food

Fossil Fuels to Solar Energy

The richest and most easily extracted ores are used first.

These resources are growing more scarce. Topsoil

◦ Depletion rates are currently 100 times that of formation in the US.

◦ Globally experts think 40% of agricultural land is seriously degraded.

◦ In some areas this number is as high as 75%.◦ The current answer is

petroleum-based fertilizers.

Mineral Resources

Global water consumption has tripled over the last 50 years and continues to climb.

Although climate change may lead to more rain it is thought that is may lead to increased periods of aridness followed by intense downpours.

We likely face greater risk of flooding and drought.

70% of water is used for agriculture◦ So hunger will arrive before thirst

Water

1.2Billion people without access to potable water.

Less than 1/3 of the world has access to abundant water supplies.

It is possible that in 2025 50% of the world’s population could be living in water shortage areas, according to some studies.

Current use patterns are drying up existing sources faster than they can be replenished.

Water

The future is uncertain:◦ We lack adequate data.◦ Consumption patterns and technology can alter

the demand.◦ Climate change could have drastic impacts on the

hydrologic cycle, but it is unclear exactly what those impacts will be.

Water

For the most part extraction of renewable stocks of significance is presently limited by resource scarcity, not lack of infrastructure.

A shortage of fish is caused by inadequate supply, not lack of fishing boats.

Renewable Resources

Presently, if we deplete one species of fish we simply switch to another.

Economists cite this ability to substitute as evidence that the limits are boundless.

However, the fishing fleets are already in place ready to deplete the next stock.

We run the risk of harvesting substitute species to extinction before we can even determine the sustainable yields.

Renewable Resources

Cod Orange Roughy

Ecosystem services are destroyed by the harvest of their structural components (i.e. the renewable resources of which they are composed)

This may be worse than the danger of raw materials depletion

In poor countries forest cover is being depleted at ~140,000km2/year

Renewable Resources

We understand marine ecosystems less well than terrestrial ecosystems.

However, it seems highly likely that fish populations are crucial to the system and the services it provides.

We know oysters filter entire estuaries and have seen this service decline in the Chesapeake Bay.

Renewable Resources

All economic activity produces waste:◦ Accumulation of toxins impact humans◦ Toxins also impact ecosystems and can degrade

their services. Evidence suggest we are overwhelming the

waste absorption capacity of the planet. CO2 is accumulating in the atmosphere.

◦ This has led to international discussions, but so far no clear movement or participation by the US

Waste Absorption Capacity

Heavy Metals◦ Remain indefinitely ◦ Bioaccumulation – not released when ingested and passed

along the food chain Nuclear Waste

◦ Break down but not on a human time frame◦ Would need to be sequestered for 50 times as long as

civilization has existed Halogenated Hydrocarbons

◦ Ozone depletion Persistent Organic Pollutants

◦ Capable of affecting reproductive capacity of many species◦ Will persist in the environment for long periods of time

Waste Absorption Capacity

A recent study found a 3km thick layer of pollution over South Asia.

It is reducing solar energy throughout by 15% in the region.

It is preventing heat from escaping. Risk of thousands of premature deaths. Likely to increase monsoon flooding in some

areas. Could reduce precipitation by up to 40% in

some areas.

Severe Pollution Is Here

Sink filling faster than sources are being emptied.

This makes sense as anyone can use the sink.◦ Rival and non-excludable

Sources are typically rival and excludable resources◦ Typically they are privately or publicly owned and

managed.

The sink is full

A rapid assessment of resources suggests we are in a full world.

Continued physical expansion of the economy threatens to impose unacceptable costs.

Typically people are worried about the sources, but it seems we should really be worried about the sink .

We are far exceeding the waste absorption capacity of the planet.

The Point