Thursday, March 24, 2016

Bill Gates, Don't Expect a Miracle

Bill Gates has said for years that we need an "energy miracle" to deal with global warming, so we should invest heavily in research and development of clean energy.

He explains that he saw the need for a miracle when he came up with this equation:

Total CO2 emissions = World population x Services used per person x Energy used to provide each service x CO2 emitted by each unit of energy. 

We need to get total emissions down to zero, and the only way to do this is to get the amount of CO2 emitted by each unit of energy down to zero.  Hence, Gates says, we need an "energy miracle," a form of energy that emits no CO2 and that is so cheap it will take over the market completely. 

Gates has often been criticized on the grounds that we don't need a miracle to develop cheap, clean energy; we just need current trends to continue.  The costs of solar energy, wind energy, and battery storage are going down rapidly. Wind and solar energy are already cheap enough to deploy massively, and batteries will soon be cheap enough to deal with their intermittency. Yes, it is still important to fund research and development in clean energy and storage, but it is also important to deploy clean energy on a large scale - and Bill Gates is working against deployment by saying that we need a miracle before it is possible.

Gates has also been criticized on the grounds that his equation merely repeats without attribution the Kaya identity, an equation from a 1993 book by a Japanese energy economist - an unconscious act of plagiarism. 

I would add that Gates should be criticized for taking the sort of narrow view that is typical of people who look for technological miracles.  He imagines such a dramatic solution to the problem only because he defines the problem so narrowly. 

Global warming is just one aspect of the larger ecological challenge that we face as world population and affluence grow. Likewise, the Kaya identity is just one aspect of the more general IPAT equation, which says:

Total environmental impact = World population x Services used per person x Environmental impact per service. 

Gates' equation (the Kaya identity) says we can reduce one of our environmental impacts to zero: we can reduce CO2 emissions to zero if we develop energy with zero emissions. 

But the IPAT equation shows that we cannot possibly reduce all of our environmental impacts to zero.  No matter how much we try to reduce our impact, there will still be some impact per service.  We cannot get that factor down to zero. 

For example, solar energy can have zero CO2 emissions, but it has an impact by using land. If our energy consumption grows indefinitely, we will eventually cover the entire land area of the earth with solar panels. All forms of clean energy use some resources, and because resources are finite, we cannot increase energy consumption indefinitely. 

Services also use other resources. If the world's population and affluence grow indefinitely, we will not have enough land to grow food for everyone, we will not have enough water for everyone, we will not have enough steel to produce cars for everyone, we will not have enough rare earth elements to build energy-efficient motors for everyone, and so on. 

You must define problems narrowly in order to come up with technological "miracles" that solve these problems. I don't deny the value of these technological advances, and I dearly would like to see major advances in clean energy and storage. But these new technologies are not miracles that will solve all our problems.

Our larger ecological challenge is caused by increasing population and increasing per capita consumption of services, as well as by the ecological impact per service. We should make an ongoing effort to reduce the ecological impact per service as much as possible, but we should realize that we will never have a technological miracle that reduces it to zero.  This means that we also need to control population growth and to limit per capita consumption of services.

Impact per service is decreasing, world population growth is slowing, but per capita consumption is increasing rapidly. International comparisons show that increased consumption no longer increases happiness after a nation reaches about half the current American level.  Yet nations all over the world - including the most affluent nations - are calling for rapid economic growth.

Technological advances will help, but they are not enough in themselves to deal with the world's ecological challenges.  We also need the wisdom to know when we have enough.