A carbon tax is an environmental tax on emissions of carbon dioxide and other greenhouse gases. It is an example of a pollution tax.
Carbon atoms are present in every fossil fuel (coal, petroleum, and natural gas) and are released as CO2 when they are burnt. In contrast, non-combustion energy sources—wind, sunlight, hydropower, and nuclear—do not convert hydrocarbons to carbon dioxide. Accordingly, a carbon tax is effectively a tax on the use of fossil fuels, and only fossil fuels. Some schemes also include other greenhouse gases; the global warming potential is an internationally accepted scale of equivalence for other greenhouse gases in units of tonnes of carbon dioxide equivalent.
Because of the link with global warming, a carbon tax is sometimes assumed to require an internationally administered scheme. However, that is not intrinsic to the principle. The European Union considered a carbon tax covering its member states prior to starting its emissions trading scheme in 2005. The UK has unilaterally introduced a range of carbon taxes and levies to accompany the EU ETS trading regime. Note that emissions trading systems do not constitute a Pigovian tax, because they entail the creation of a property right.
The purpose of a carbon tax is to protect the environment by reducing emissions of carbon dioxide and thereby slow climate change. It can be implemented by taxing the burning of fossil fuels—coal, petroleum products such as gasoline and aviation fuel, and natural gas—in proportion to their carbon content. Unlike other approaches such as carbon cap-and-trade systems, direct taxation has the benefit of being easily understood and can be popular with the public if the revenue from the tax is returned by reducing other taxes. Alternatively, it may be used to fund environmental projects.
In economic theory, pollution is considered a negative externality because it has a negative effect on a party not directly involved in a transaction. To confront parties with the issue, the economist Arthur Pigou proposed taxing the goods (in this case fossil fuels) which were the source of the negative externality (carbon dioxide) so as to accurately reflect the cost of the goods' production to society, thereby internalizing the costs associated with the goods' production. A tax on a negative externality is termed a Pigovian tax, and should equal the marginal damage costs.
A carbon tax is an indirect tax—a tax on a transaction—as opposed to a direct tax, which taxes income. As a result, some American conservatives have supported such a carbon tax because it taxes at a fixed rate, independent of income, which complements their support of a flat tax.
Prices of carbon (fossil) fuels are expected to continue increasing as more countries industrialize and add to the demand on fuel supplies. In addition to creating incentives for energy conservation, a carbon tax would put renewable energy sources such as wind, solar and geothermal on a more competitive footing, stimulating their growth. Former Federal Reserve chairman Paul Volcker suggested (February 6, 2007) that "it would be wiser to impose a tax on oil, for example, than to wait for the market to drive up oil prices."
Social cost of carbon
Many estimates of aggregate net economic costs of damages and benefits from climate change across the globe, the social cost of carbon (SCC), expressed in terms of future net benefits and costs that are discounted to the present, are now available. Peer-reviewed estimates of the SCC for 2005 have an average value of US$43 per tonne of carbon (tC) (i.e., US$12 per tonne of carbon dioxide) but the range around this mean is large. For example, in a survey of 100 estimates, the values ran from US$–10 per tonne of carbon (US$–3 per tonne of carbon dioxide) up to US$350/tC (US$95 per tonne of carbon dioxide.)
One must be very careful when comparing weights of carbon versus carbon dioxide, since carbon comprises only 27.29% (12.0107 / [12.0107 + 2 × 15.9994]) of the mass of carbon dioxide. In simple terms, there are only 27 tonnes of carbon in 100 tonnes of carbon dioxide.
In an October, 2006, report entitled the Stern Review by then HM Treasury official and former Chief Economist and Senior Vice-President of the World Bank, Nicholas Stern, he states that climate change could affect growth which could be cut by one-fifth unless drastic action is taken. Stern has warned that one percent of global GDP is required to be invested in order to mitigate the effects of climate change, and that failure to do so could risk a recession worth up to twenty percent of global GDP. Stern’s report suggests that climate change threatens to be the greatest and widest-ranging market failure ever seen. The report has had significant political effects: Australia reported two days after the report was released that they would allot AU$60 million to projects to help cut greenhouse gas emissions. The Stern Review has been criticized by some economists, saying that Stern did not consider costs past 2200, that he used an incorrect discount rate in his calculations, and that stopping or significantly slowing climate change will require deep emission cuts everywhere.
According to a 2005 report from the Association of British Insurers, limiting carbon emissions could avoid 80% of the projected additional annual cost of tropical cyclones by the 2080s. A June 2004 report by the Association of British Insurers declared "Climate change is not a remote issue for future generations to deal with. It is, in various forms, here already, impacting on insurers' businesses now." It noted that weather risks for UK households and property were already increasing by 2–4% per year due to changing weather, and that claims for storm and flood damages in the UK had doubled to over £6 billion over the period 1998–2003, compared to the previous five years. As a result insurance premiums are rising. In the UK the insurance industry normally offers insurance against natural disasters, however there is a risk that in some areas flood insurance will become unaffordable for some, and it has been mooted that cover may be withdrawn in some areas entirely unless there is government backing.
In the U.S., according to Choi and Fisher (2003) each 1% increase in annual precipitation could enlarge catastrophe loss by as much as 2.8%. Financial institutions, including the world's two largest insurance companies, Munich Re and Swiss Re, warned in a 2002 study that "the increasing frequency of severe climatic events, coupled with social trends" could cost almost US$150 billion each year in the next decade. These costs would, through increased costs related to insurance and disaster relief, burden customers, taxpayers, and industry alike.
Concerns have been raised about carbon leakage which is the tendency for energy-intensive industries to migrate from nations with a carbon tax to those nations without a carbon tax where some of the receiving nations might be less energy-efficient. A possible antidote is for carbon-taxing countries to levy carbon-equivalent fees on imports from non-taxing nations.
Petroleum (motor gasoline, diesel, jet fuel)
Many OECD countries have taxed fuel directly for many years for some applications; for example, the UK imposes duty directly on vehicle hydrocarbon oils, including petrol and diesel fuel. The duty is adjusted to ensure that the carbon content of different fuels is handled with equivalence.
While a direct tax should send a clear signal to the consumer, its use as an efficient mechanism to influence consumers' fuel use has been challenged in some areas:
* There may be delays of a decade or more as inefficient vehicles are replaced by newer models and the older models filter through the 'fleet'.
* There may be practical political reasons that deter policy makers from imposing a new range of charges on their electorate.
* There is some evidence that consumers' decisions on fuel economy are not entirely aligned to the price of fuel. In turn, this can deter manufacturers from producing vehicles that they judge have lower sales potential. Other efforts, such as imposing efficiency standards on manufacturers, or changing the income tax rules on taxable benefits, may be at least as significant.
* In many countries fuel is already taxed to influence transport behavior and to raise other public revenues. Historically, they have used these fuel taxes as a source of general revenue, as their experience has been that the price elasticity of fuel is low, thus increasing fuel taxation has only slightly impacted on their economies. However, in these circumstances the policy behind a carbon tax may be unclear.
Some also note that a suitably priced tax on vehicle fuel may also counterbalance the "rebound effect" that has been observed when vehicle fuel consumption has improved through the imposition of efficiency standards. Rather than reduce their overall consumption of fuel, consumers have been seen to make additional journeys or purchase heavier and more powerful vehicles.