In the first part on the mitigation policy curve I looked at

• The Small Country Problem. How one small country acting unilaterally will make an insignificant impacts of global climate change.
• How it is very likely to be against the economic interests of any country to join the small group of countries already with climate mitigation policies.

In this section I will look at two examples that go completely against logical thinking. There can be instances (like in Britain) where bold policies increase global warming at great cost to that economy, but the shale gas, which constrains global warming at net benefit to the gas-producing country?

To see the effect of policy, there is a need for analysis both at the front-end (prior to implementation), during and after. The question is about the gradient of the policy cost curve, at the point

Policy increasing global emissions?

We know that policy countries are in a minority of countries. With the structure of global growth this amount will fall.

Look at the long-term. Implementing a policy, you are saying to businesses that, ceteris paribus, your energy costs are going to rise year-on-year relative to those in non-policy countries. There will be a bigger incentive to make technological efficiency gains in these countries, but those gains can be transplanted to non-policy countries. In this global emissions may decrease more rapidly than they would have done, but the policy countries bear well over 100% of the costs and it becomes a policy benefit to the non-policy countries. By implication they will achieve around 200% of the global decline in emissions.

Question is, will it be more or less than 200% of the decline? Could it be that the policy countries energy-efficient factories are replaced by less energy-efficient factories in the non-policy countries?
There is some economic theory needed here. The Solow growth model shows a technological growth curve. Developing countries can achieve rapid growth by adapting to higher-productivity by adapting existing technologies. Their lower-unit labour costs will enable to undercut the more advanced economies, but the growth in these economies will grow the global economy as well. Most of this is unit labour costs. But by adapting previous generation technologies and exploiting labour costs less than a tenth those of the rich countries, they can under-cut the rich world. Greater technological advance is mostly in unit labour costs, but it can also mean lower unit energy costs. The portion of global output transferred from the rich countries to the poorer developing countries could result in higher total energy use, and ceteris paribus, higher CO2 emissions.

What is clear is that policy countries will increase unit energy costs. There is a two-pronged approach in Britain. The European-wide carbon-trading scheme will restrict supply of energy, bidding up the price. But also renewables cost more than fossil fuels. So the two-pronged approach doubly increases unit energy costs. Increasing unit energy costs accelerates the switching of manufacturing to developing countries, mostly China. The blue bit above postulates that energy per unit of output is globally could increase. But that is part of the problem. China has much higher CO2 emissions per unit of output as Britain. If Britain’s aggressive rush to renewables is successful, then this gap will increase, as much of Chinese energy output is from coal. A de-carbonised British economy will also be a de-industrialised one. But overall global emissions will have increased through switching of output to China.

The biggest cost of the policy for Britain is nothing to do with switching low-CO2 emitting production to high CO2 emitting countries. It is the restriction on economic growth. Loss of jobs from manufacturing, and pushing up higher energy costs elsewhere constrains growth. Due to the long-term consequences of that pushes policy costs through the roof. In the sectors where jobs are lost overseas, the policy curve is positive. If British Climate Change Act 2008 is massively unsuccessful in meeting the carbon targets, it could be a very expensive policy to increase global CO2 emissions.

The Shale-Gas Counter Example

In the USA, a consequence of the shale gas revolution has been to drastically reduce unit energy costs to industry. But also there has been a switch away from coal. As CO2 emissions of gas are around half that of coal, US CO2 emissions have been falling with electricity prices. The US is enjoying both cheaper and cleaner energy. Consequently, some chemical factories that relocated to China have returned to the USA. China has a greater proportion in its electricity production than USA, and the gap is widening. So the switching of a factory from USA reduces global CO2 emissions, even though the total energy usage remains the same.

Let me show this graphically.

Suppose (as is likely at present), the Climate Change Act 2008 falls a long way short of its target but unintentionally moves a substantial part of manufacturing to China through higher costs. For Britain this will be a large cost relative to British, but may be a net contributor to global warming. The policy curve points gets a positive slope! Conversely, “free market” shale gas in the USA has constrained global carbon emissions doubly by reducing US carbon emissions per unit of output, and switching production from China, where carbon emissions per unit of output are higher. It is having positive benefits on the US economy as well (hence negative costs), whilst constraining (slightly) the top-end of global warming.