A carbon tax is a tax levied on the carbon content of fuels (transport & energy sector) and, like carbon emissions trading, is a form of carbon pricing. The term carbon tax is also used to refer to a carbon dioxide equivalent tax, the latter of which is quite similar^[1] but can be placed on any type of greenhouse gas or combination of greenhouse gases, emitted by any economic sector.^[2]

As of 2018 at least 27 countries and subnational units have implemented carbon taxes.^[3] Research shows that carbon taxes effectively reduce greenhouse gas emissions.^[3] Economists generally argue that carbon taxes are the most efficient and effective way to curb climate change, with the least adverse effects on the economy.^[4][5][6][7]

When a hydrocarbon fuel such as coal, petroleum, or natural gas is burnt, its carbon is converted to carbon dioxide (CO2) and other compounds of carbon. CO2 is a heat-trapping greenhouse gas which causes global warming, which damages the environment and human health. Since greenhouse gas emissions from the combustion of fossil fuels are closely related to the carbon content of the respective fuels, this negative externality can be compensated for by taxing the carbon content of fossil fuels at any point in the product cycle of the fuel.^[8][9][10]

Carbon taxes offer a potentially cost-effective means of reducing greenhouse gas emissions.^[11] From an economic perspective, carbon taxes are a type of Pigovian tax^[12] and help to address the problem of emitters of greenhouse gases not facing the full social cost of their actions. To prevent them being regressive taxes carbon tax revenues can be spent on low-income groups.^[13]

Carbon dioxide is one of several heat-trapping greenhouse gases (GHGs) emitted by humans (anthropogenic GHGs) and the scientific consensus is that human-induced greenhouse gas emissions are the primary cause of global warming,^[14] and that carbon dioxide is the most important of the anthropogenic GHGs.^[15] Worldwide, 27 billion tonnes of carbon dioxide are produced by human activity annually.^[16] The physical effect of CO2 in the atmosphere can be measured as a change in the Earth-atmosphere system's energy balance – the radiative forcing of CO2.^[17] Carbon taxes are one of the policies available to governments to reduce GHG emissions.^[18]

In the Kyoto Protocol (an international treaty), CO2 emissions are regulated along with other GHGs. Different GHGs have different physical properties: the global warming potential is an internationally accepted scale of equivalence for other greenhouse gases in units of tonnes of carbon dioxide equivalent.

A carbon tax is a form of pollution tax.^[20] Pollution taxes are often grouped with two other economic policy instruments: tradable pollution permits/credits and subsidies. These three environmental economic policy instruments are built upon a foundation of a command and control regulation. The difference is that classic command-penalty regulations stipulate, through performance or prescriptive standards, what each polluter is required to do to be in compliance with the law. Command and control regulation is not considered an economic instrument as it is typically enforced by narrower means such as stop or control order, though it may include an administrative monetary penalty in site-specific regulations.^[21] The instrumental distinction between a tax and a command-and-control regulation is determined by the enacted legislative names, and whether they contain "tax" as a defined term within the Act, for example British Columbia's Carbon Tax Act ^[270] versus Alberta's Specified Gas Emitters Regulation, Alta Reg 139/2007 ^[271]

A carbon tax is also an indirect tax—a tax on a transaction—as opposed to a direct tax, which taxes income. A carbon tax is called a price instrument, since it sets a price for carbon dioxide emissions.^[22] In economic theory, pollution is considered a negative externality, a negative effect on a party not directly involved in a transaction, which results in a market failure. To confront parties with the issue, the economist Arthur Pigou proposed taxing the goods (in this case hydrocarbon 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 called a Pigovian tax, and should equal the marginal damage costs.

Within Pigou's framework, the changes involved are marginal, and the size of the externality is assumed to be small enough not to distort the rest of the economy.^[23] According to the scientific consensus, the impact of climate change may result in catastrophe and non-marginal changes.^[24][25] "Non-marginal" means that the impact could significantly reduce the growth rate in income and welfare. The amount of resources that should be devoted to climate change mitigation is controversial.^[24] Policies designed to reduce carbon emissions could also have a non-marginal impact, but not catastrophic.^[26]

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. David Gordon Wilson first proposed a carbon tax in 1973.^[27]

In January 2019, economists published a statement in The Wall Street Journal calling for a carbon tax, describing it as "the most cost-effective lever to reduce carbon emissions at the scale and speed that is necessary." By February 2019, the statement had been signed by more than 3,000 U.S. economists, including 27 Nobel Laureate Economists.^[7]

The social cost of carbon (SCC) is the marginal cost of the impacts caused by emitting one extra tonne of carbon (as carbon dioxide) at any point in time, inclusive of ‘non-market’ impacts on the environment and human health.^[28] The concept of a social cost of carbon was first mooted by the Reagan administration of the United States in 1981. The initial purpose of putting a price on a ton of emitted CO2 was to aid policymakers in evaluating whether a policy designed to curb climate change is justified. An intuitive way of looking at this is as follows: if the price of carbon is $50 per tonne in 2030, and we currently have a technology that can reduce emissions by 1 million metric tonnes in 2030, then any investment amount below $50 million minus interests would make economic sense, while any amount over that would lead us to consider investing the money somewhere else, and paying to reduce emissions in 2030.^[29]

Calculating the SCC requires estimating the residence time of carbon dioxide in the atmosphere, along with estimating the impacts of climate change. The impact of the extra tonne of carbon dioxide in the atmosphere must then be converted to equivalent impacts on climate and human health, as measured by the amount of damage done and the cost to fix it. In economics, comparing impacts over time requires a discount rate. This rate determines the weight placed on impacts occurring at different times.

Best estimates of the SCC come from Integrated Assessment Models (IAM) which predict the effects of climate change under various scenarios and allow for calculation of monetized damages. One of the most widely used IAMs is the Dynamic Integrated model of Climate and the Economy (DICE).

The DICE model, developed by William Nordhaus, makes provisions for the calculation of a social cost of carbon. The DICE model defines the SCC to be "equal to the economic impact of a unit of emissions in terms of t-period consumption as a numéraire".^[30]

The SCC figure computed in 2015 is $31.2 per ton of CO2 for emissions, this amount will rise 3% in real terms, until 2050.^[30] Estimates of the dollar cost of carbon dioxide pollution is given per tonne, either carbon, $X/tC, or carbon dioxide, $X/tCO2. One tC is roughly equivalent to 3.7 tCO2.^[31]

According to economic theory, if SCC estimates were complete and markets perfect, a carbon tax should be set equal to the SCC. Emission permits would also have a value equal to the SCC. In reality, however, markets are not perfect, SCC estimates are not complete, and externalities in the market are difficult to calculate accurately, resulting in an inaccurate carbon tax (Yohe et al.., 2007:823).^[32] The 2018 IPCC report suggested that a tax of hundreds or even thousands of dollars per ton would be needed to drive carbon emissions to zero.^[33]

Estimates of the SCC are highly uncertain.^[34] The wide range of estimates is explained mostly by underlying uncertainties in the science of climate change (e.g., the climate sensitivity, which is a measure of the amount of global warming expected for a doubling in the atmospheric concentration of CO2), different choices of discount rate, different valuations of economic and non-economic impacts, treatment of equity, and how potential catastrophic impacts are estimated.^[35] One specific issue arises over coming to a consensus on what discount rate to use. Some, like Nordhaus, advocate for a discount rate that is pegged to current market interest rates, as we should treat efforts to reduce carbon dioxide emissions just like we treat any other economic activity. Others, like Stern, propose a much smaller discount rate because "normal" discount rates are skewed when applied over the time scales over which climate change acts.^[36] As a result, other estimates of the SCC spanned at least three orders of magnitude, from less than $1/tC to over $1,500/tC.^[35] The true SCC is expected to increase over time.^[35] The rate of increase will very likely be 2 to 4% per year.^[35] A 2014 meta-analysis of the literature on the estimates of the social costs of carbon, however, finds evidence of publication bias in favor of larger estimates.^[37] A 2019 meta-analysis of 578 estimates of the SCC from 58 studies finds -50 to 8752$/tC (-13.36 to 2386.91$/tCO2), with a mean value of 200.57$/tC (54.70$/tCO2).^[38]

Organizations that take an Integrated Management approach are using the social cost of carbon to help evaluate investment decisions and guide long term planning in order to consider the full extent of how their operations impact society and the environment. By placing a value on carbon emissions, decision makers can use this value to expand upon traditional financial decision making tools and create new metrics for measuring the short and long term outcomes of their actions. This means taking the triple bottom line a step further and promotes an Integrated Bottom Line (IBL) approach. Prioritizing an IBL approach begins with changing the way we think about traditional financial measurements as these do not take into consideration the full extent of the short and long term impacts of a decision or action. Instead, Return on Investment can be expanded to Return on Integration, Internal Rate of Return can evolve into Integrated Rate of Return and instead of focusing on Net Present Value, companies can plan for Integrated Future Value.^[39]

Carbon leakage is the effect that regulation of emissions in one country/sector has on the emissions in other countries/sectors that are not subject to the same regulation.^[40] Leakage effects can be both negative (i.e., increasing the effectiveness of reducing overall emissions) and positive (reducing the effectiveness of reducing overall emissions).^[41] Negative leakages, which are desirable, are usually referred to as "spill-over".^[42]

According to Goldemberg et al.. (1996, p. 28), short-term leakage effects need to be judged against leakage effects in the long-term.^[43] A policy that, for example, saw a carbon taxes set only in developed countries might lead to leakage of emissions to developing countries. However, a desirable negative leakage could occur due to a lowering in demands of coal, oil, and gas from the developed countries and thus the world prices. This will lead to developing countries being able to afford more of any hydrocarbon fuel type, thus being able to substitute more oil or gas for coal, in effect lowering their national emissions. In the long-run, however, if the transfer of less polluting technologies is delayed, this substitution by income effects might have no long-term benefit.

Carbon leakage is central to the discussion on climate policy, given the confluence of issues that are currently being debated, including the 2030 Energy and Climate Framework and the review of the EU carbon leakage list by 2014.^[44]

A number of policies have been suggested to address concerns over competitive losses due to one country introducing a carbon tax while another country does not.^[45][46] Similar policies have also been suggested in an attempt to induce countries to introduce carbon taxes. Suggested policies include border tax adjustments, trade tariffs and trade bans.

Border tax adjustments would account for emissions attributable to imports from nations without a carbon price. An alternative would be trade bans or tariffs applied to non-taxing countries. It has been argued that such approaches could be disadvantageous to a target country as a trade measure (Gupta et al.., 2007).^[11] To date, World Trade Organization case law has not provided specific rulings on climate-related taxes. The administrative aspects of border tax adjustments has also been discussed.^[47]

Two other types of taxes that are related to carbon taxes are emissions taxes and energy taxes. An emissions tax on GHG emissions requires individual emitters to pay a fee, charge or tax for every tonne of greenhouse gas released into the atmosphere^[11] while an energy tax is charged directly on the energy commodities.

In terms of climate change mitigation, a carbon tax, which is levied according to the carbon content of fuels, is not a perfect substitute for a tax on CO2 emissions.^[48] For example, a carbon tax encourages reduced use of hydrocarbon fuels, but it does not provide an incentive to mitigate or improve mitigation technologies, e.g. carbon capture and storage.

Energy taxes increase the price of energy uniformly, regardless of the emissions produced by the energy source (Fisher et al.., 1996, p. 416). An ad valorem energy tax is levied according to the energy content of a fuel or the value of an energy product, which may or may not be consistent with the emitted amounts of green house gases and their respective global warming potentials. Studies indicate that to reduce emissions by a certain amount, ad valorem energy taxes would be more costly than carbon taxes.^[18] However, although CO2 emissions are an externality, using energy services may result in other negative externalities, e.g., air pollution. If these other externalities are accounted for, an energy tax may be more efficient than a carbon tax alone.

Another type of tax is a fee and dividend, where the money collected from the tax is returned equitably to all households, effectively taxing carbon emitters and rebating those that burn less carbon.

Many OECD countries have taxed fuel directly for many years for some applications; for example, the UK imposes a hydrocarbon oil duty directly on vehicle hydrocarbon oils, including petrol and diesel fuel.

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:^[49]

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.^[50]

A carbon tax that compensates for the SCC varies by fuel source. The carbon dioxide production of the fuel source per unit mass or volume is multiplied by the SCC to obtain the tax. Based on the mean peer reviewed value ($43/tC or $12/tCO2, see Social cost of carbon, above), the table below estimates the tax:

Note that the tax per kWh of electricity depends on the thermal efficiency of the generating power plant, which varies from power plant to power plant. The table follows the American Physical Society (APS) estimate of 10.3 BTU/Wh (33%).^[53] The APS notes that "It is expected that future plants, especially those based on gas turbine systems, often will have higher efficiency, in some cases exceeding 50%."The highest efficiency reached is 62% by the new EDF powerplant in Bouchain^[54] A theoretical conversion rate of 100% is 3.412 BTU/Wh. A more practical limit for thermal power plants is Carnot's theorem.

Research shows that carbon taxes effectively reduce greenhouse gas emissions.^[3][55][56] There is overwhelming agreement among economists that carbon taxes are the most efficient and effective way to curb climate change, with the least adverse effects on the economy.^{[4][5][6][7][57][58]}

A study in the American Economic Journal, using the synthetic control method, found that Sweden's carbon tax successfully reduced carbon dioxide emissions from transport by 11%.^[55] A 2015 study of carbon taxes in British Columbia found that the taxes reduced greenhouse gas emissions by 5–15% while having negligible overall economic effects.^[56] A 2017 study of the British Columbia carbon tax found that industries on the whole benefitted from the tax and "a small but statistically significant 0.74 percent annual increases in employment" but that carbon-intensive and trade-sensitive industries were adversely affected.^[59]

A number of studies have found that in the absence of an increase in social benefits and tax credits, a carbon tax would hit poor households harder than rich households.^{[60][61][62][63]} Tufts University economist Gilbert E.Metcalf has disputed that carbon taxes would be regressive in the U.S. context.^[64]

Both energy and carbon taxes have been implemented in responses to commitments under the United Nations Framework Convention on Climate Change.^[18] In most cases where an energy tax or carbon tax is implemented, the tax is implemented in combination with various forms of exemptions.

Carbon Tax is payable in foreign currency at the rate of US$0.03 (3 cents) per litre of petroleum and diesel products or 5% of cost, insurance and freight value (as defined in the Customs and Excise Act [Chapter 23:02]), whichever is greater.^[66]

A tax on emissions has been proposed for South Africa. Announced by Finance Minister Pravin Gordhan, the tax will be implemented starting September 1, 2015 on new motor vehicles.^[67] This tax will apply at the time of sale, and will be related to the amount of CO2 emitted by the vehicle. 75 South African Rand will be added to the price for every gram of CO2 per kilometer the vehicle emits over 120 g/km. The tax will apply to passenger cars first and eventually to commercial vehicles.^[68] Bakkies (pickup trucks) will be taxed because they are often used as passenger vehicles: this has caused an uproar for fear of affecting industry.

David Powels of the National Association of Automobile Manufacturers of South Africa (NAAMSA), opposes this taxation on light commercial vehicles.^[67] The tax could increase the cost of new vehicles by 2.5% and cause a decrease in total automobile sales: in addition, Powels questions the ability to accurately predict CO2 emissions based on engine capacity.^[69] NAAMSA acknowledges the ability of carbon taxes to change consumer behavior for the betterment of the environment, but argues that this tax is not transparent enough for consumers because the taxation occurs at the time of automobile production.^[69] Powels says the tax is discriminatory because it targets new vehicles, and that the government should focus on introducing "green fuel" to South Africa.^[69]

The goal of the carbon tax is to put South Africa on a "sustainable path".^[70] South Africa has produced Long Term Mitigation Scenarios (LTMS) to address climate policy issues that consider variables such as technology, investment, and policy (including carbon taxes) and to clarify South Africa's position for potential UNFCC negotiations.^[70]

The Chinese Government Ministry of Finance had proposed to introduce a carbon tax from 2012 or 2013, based on carbon dioxide output from hydrocarbon fuel sources such as oil and coal.^[71][72] The introduction of a carbon tax in China might affect the internal market, as well as many other laws and regulations of the country, but given the size of Chinese economy also contribute importantly to the mitigation of climate change.^[73]

On July 1, 2010, India introduced a nationwide carbon tax of 50 rupees per tonne ($1.07/t) of coal both produced and imported into India. In a budget speech in 2014, the finance Minister increased the price to 100 rupees per tonne ( $1.60/t at $60.5 conversion)^[74] In India coal is used to power more than half of the country's electricity generation.^[75]

India's total coal production is estimated to reach 571.87 million tons in the year ending March 2010 and is expected to import around 100 million tons. The carbon tax expects to raise 25 billion rupees ($535 million) for the financial year 2010–2011. According to then Finance Minister Pranab Mukherjee, the clean energy tax will help to finance a National Clean Energy Fund (NCEF).^[75] Industry bodies have not favored the levy and fear that the resultant higher price of coal could trigger inflation.^[74]

While many remain apprehensive, a carbon tax is a step towards helping India meet their voluntary target to reduce the amount of carbon dioxide released per unit of gross domestic product by 25% from 2005 levels by 2020. Environment Minister Jairam Ramesh told reporters in June 2010 that a domestic tax should come before a global carbon tax, and India has imposed one while others debate the issue. With the new government in India under PM Narendra Modi, the carbon tax has been further increased form 100Rs per tonne to 200Rs per tonne in the Budget 2015-16.^[75][76] Currently the carbon tax stands at 400rs per tonne.

In October 2012, Japan introduced a Carbon tax with the goal to take action on mitigating dangerous climate change. The government plans to use the revenues generated from this tax to finance clean energy and energy saving projects.^[77]

In December 2009, nine industry groupings opposed a carbon tax at the opening day of the COP-15 Copenhagen climate conference stating, "Japan should not consider a carbon tax as it would damage the economy which is already among the world's most energy efficient." The industry groupings represented the oil, cement, paper, chemical, gas, electric power, auto manufacturing and electronics, and information technology sectors. The sectors state that "the government has neither studied nor explained thoroughly enough why such a carbon tax is needed, how effective and fair it is and how the payments are to be used."^[78]

In 2005, an environmental tax proposed by Japanese authorities was also delayed due to major opposition from the Petroleum Association of Japan (PAJ), other industries and consumers. The delay was "to avoid putting too much economic burden on end-users as they were already paying heavy taxes on hydrocarbon fuels amid high oil prices." The tax that was to be implemented would be 2,400 yen ($20.85 in 2005 dollars) per tonne of carbon dioxide emitted from fuels. Tax on coal would be about 1.58 yen per kilogram and that on gasoline 1.52 yen per litre (4.3 cents per gallon in 2005 dollars). Officials estimated that the tax would generate income of 37 billion yen a year for the government and result in a payment of 2,100 yen per year for an average household.^[79]

On 20 February 2017, Singapore proposed during the Budget that a carbon tax to promote a cleaner environment. The proposal has since been refined to tax large emitters at S$5 per tonne of carbon dioxide emitted with room for future price increases. The law on carbon tax, known as the Carbon Pricing Act, was passed on 20 March 2018.^[80][81]

On August 22, 2008, The Chong Wa Dae, also known as the Blue house – the executive office and official residence of the South Korean head of state, confirmed a list of 40 new administrative strategy agenda, which included substitution of a carbon tax with the current transportation tax.^[82] Most revenues of the tax amounting to an annual $11 trillion won ($10.4 billion) will be financed toward the "Low Carbon, Green Growth" move, which was announced in President Lee Myung-bak's speech marking the nation's 63rd Liberation day the week before the announcement.^[82] A carbon tax is imposed on emissions of greenhouse gases including carbon dioxide. The direct taxation system is now applied to several European countries, such as Sweden, the Netherlands and Norway, as well as several states in North America. The temporary transportation tax, one of the major objective taxes in the country, is slated to end in 2009. About 80 percent of its yield is used in transportation-related work like road construction. Additional taxation amendment could follow with a "tax on emissions" bottom line, in possible implementations of tax discrimination according to a vehicles' size and a carbon tax on the currently tax-free thermal power plants. Taxation on emissions is inevitable in that low carbon policies take substantial budget, the government says.^[82]

In February 2010, a deputy finance minister Yoon Young-sun confirmed that South Korea is considering a carbon tax to help reduce emissions 4% from 2005 levels by 2020.^[83] This would be in conjunction with a cap-and-trade program to be implemented later this year. With a tax rate of 31,828 won (25 Euros) per ton of CO2, the South Korean government would collect 9.1 trillion won ($7.9 billion) in tax revenue based on 2007 emissions. Income from the carbon tax would be used to reduce corporate and income taxes. On July 22, 2010, Chairman Sohn Kyung-shik of the Korea Chamber of Commerce and Industry asked for the South Korean government to delay the implementation of the carbon tax: "If the government applies much stricter guidelines over carbon emissions, then companies might be burdened."^[84]

On July 13, 2010, South Korea's government announced plans to more than double its financing for green research and development projects to 3.5 trillion won ($2.9/£1.9bn) by 2013. The finance ministry decided that the new investment will be put into a new dedicated green fund operated by the state-run Korea Finance Corporation, for distribution to private sector projects. The government said that the fund forms part of a huge low-carbon investment drive that will see it invest a total of 107.4 trillion won, or two percent of the country's annual gross domestic product, on green projects between 2009 and 2013.^[85]

However, the government signaled that in addition to setting aside state funds, it will ask private companies to contribute 2.4 trillion won to the fund. It added that spending from the fund will be directed mainly toward business involved in greenhouse gas emissions reduction and promoting energy efficiency. In addition, the government intends to expand its system of tax breaks to cover new technologies in solar, wind and thermal power, low-emission vehicles, rechargeable batteries and next generation nuclear reactors.^[85]

The government also set a voluntary target last year (2007) to reduce 2020 emissions by four percent on 2005 levels by 2020, and is expected to soon announce plans for carbon trading scheme to begin in 2012.^[85]

In October 2009, vice finance minister Chang Sheng-ho announced that Taiwan was planning to adopt a carbon tax in 2011.^[86] However, Premier Wu Den-yih and legislators stated that the carbon taxes would increase public suffering from the recession and that the government should not levy the new taxes until Taiwan's economy has recovered. He opposed the carbon tax.^[87] Many Taiwanese citizens are opposed to tax increases as well. However, Chung-Hua Institution for Economic Research (CIER), the think-tank that was commissioned by the government to advise on its plan to overhaul the nation's taxes, had recommended a levy of NT$2,000 (US$61.8, £37.6) on each tonne of CO2 emissions. CIER estimated that Taiwan could raise NT$164.7bn (US$5.1bn, £3.1bn) from the energy tax and a further NT$239bn (US$7.3bn, £4.4bn) from the carbon levy on an annual basis by 2021.^[86] If Taiwan does pass the carbon tax policy, Taiwan would become the first Asian country with taxation on carbon emissions.^[88] Due to the amount of revenues from such a comparatively high carbon tax, the government is planning to subsidize low income families and public transportation by using the revenues from carbon taxes.^[89]

On 1 July 2012, the Australian Federal government introduced a carbon price of AUD$23 per tonne of emitted CO2-e on selected fossil fuels consumed by major industrial emitters and government bodies such as councils. To offset the impact of the tax on some sectors of society, the government reduced income tax (by increasing the tax-free threshold) and increased pensions and welfare payments slightly to cover expected price increases, as well as introducing compensation for some affected industries. On 17 July 2014, a report by the Australian National University estimated that the Australian scheme had cut carbon emissions by as much as 17 million tonnes, the biggest annual reduction in greenhouse gas emissions in 24 years of records in 2013 as the carbon tax helped drive a large drop in pollution from the electricity sector.^[90]

On 17 July 2014, the Abbott Government passed repeal legislation through the Senate, and Australia became the first nation to abolish a carbon tax.^[91] In its place, the government set up the Emission Reduction Fund, paid by taxpayers from consolidated revenue, which according to RepuTex, a markets consultancy, estimated the government's main climate policy may only meet a third of the emissions reduction challenge if Australia is to cut 2000 levels by 5% by 2020.^[92]

In 2005, the Fifth Labour Government proposed a carbon tax in order to meet obligations under the Kyoto Protocol. The proposal would have set an emissions price of NZ$15 per tonne of CO2-equivalent. The planned tax was scheduled to take effect from April 2007, and applied across most economic sectors though with an exemption for methane emissions from farming and provisions for special exemptions from carbon intensive businesses if they adopted world's-best-practice standards of emissions.^[93]

After the 2005 election, some of the minor parties supporting the Fifth Labour Government (NZ First and United Future) opposed the proposed tax, and it was abandoned in December 2005.^[94] In 2008, the New Zealand Emissions Trading Scheme was enacted via the Climate Change Response (Emissions Trading) Amendment Act 2008.^[95]

In Europe, a number of countries have imposed energy taxes or energy taxes based partly on carbon content.^[18] These include Denmark, Finland, Germany, Ireland, Italy, the Netherlands, Norway, Slovenia, Sweden, Switzerland, and the UK. None of these countries has been able to introduce a uniform carbon tax for fuels in all sectors. For a review of Europe's experience with carbon taxation see Andersen (2010).^[96]

During the 1990s, a carbon/energy tax was proposed at the EU level but failed due to industrial lobbying.^[97] In 2010, the European Commission considered implementing a pan-European minimum tax on pollution permits purchased under the European Union Greenhouse Gas Emissions Trading Scheme (EU ETS) in which the proposed new tax would be calculated in terms of carbon content rather than volume, so that fuels with high energy concentrations, despite their subsequently high carbon content, will no longer carry the same traditionally low price.^[98] According to the European Commission, the new plan will charge firms a minimum tax per tonne of carbon dioxide emissions^[99] at a suggested rate of €4 to €30 per tonne of CO2.^[100]

As of the year 2002, the standard carbon tax rate since 1996 amounts to 100 DKK per tonne of CO2, equivalent to approximately €13 or US$18. Net carbon emission tax from fuel combustion can vary depending on the level of pollution each source emits, the tax rate varies between 402 DKK per tonne of oil to 5.6 DKK per tonne of natural gas and 0 for non-combustible renewables. The rate for electricity is 1164 DKK per tonne or 10 øre per kWh, equivalent to .013 Euros or .017 US dollars per kWh. The CO2 tax applies to all energy users, including the industrial sector. But the industrial companies can be taxed differently according to two principles: the process the energy is used for, and whether or not the company has entered into a voluntary agreement to apply energy efficiency measures. Danish policies like this provide incentives for companies to put in place more sustainable practices similar to a cap and trade program on carbon dioxide.^[101]

In 1992, Denmark issued a carbon dioxide tax, which was about $14 for business and $7 for households, per ton of CO2. However, Denmark offers a tax refund for energy efficient changes. One of the main goals for the tax is to have people change their habits, because most of the money collected would be put into research for alternative energy resources.^[102]

Finland was the first country in the 1990s to introduce a CO2 tax, initially with few exemptions for specific fuels or sectors.^[103] Since then, however, energy taxation has been changed many times and substantially. These changes were related to the opening of the Nordic electricity market. Other Nordic countries exempted energy-intensive industries, and Finnish industries felt disadvantaged by this. Finland did place a border tax on imported electricity, but this was found to be out of line with EU single market legislation. Changes were then made to the carbon tax to partially exclude energy-intensive firms. This had the effect of increasing the costs of reducing CO2 emissions (p. 16).

Vourc'h and Jimenez (2000, p. 17) stated that arguments based on competitive losses needed to be viewed with caution. For example, they suggested that carbon tax revenues could be used to reduce labour taxes, which would favour the competitiveness of non energy-intensive industries.

In 2009, France detailed a new carbon tax with a new levy on oil, gas and coal consumption by households and businesses that was supposed to come into effect on January 1, 2010. The new carbon tax would affect households and businesses, which would have raised the cost of a litre of unleaded fuel by about four euro cents (25 US cents per gallon). The total estimated income from the carbon tax would have been between €3-4.5 billion annually, with 55 percent of profit coming from households and 45 percent coming from businesses.^[104] The tax would not have applied to electricity, which comes mostly from nuclear power.^[105]

On December 30, 2009, the bill was blocked by the French Constitutional Council, which said it included too many exceptions.^[106] Among those exceptions, certain industries were excluded which would have made the taxes unequal and inefficient, it said.^[107] They included exemptions for agriculture, fishing, trucking, and farming.^[104] French President Nicolas Sarkozy, although he vowed to "lead the fight to save the human race from global warming", was forced to back down after mass social protests led to strikes and a social disruption.^[108] He also wanted support from the rest of the European Union before it would alone proceed with a carbon tax.^[109]

In 2014, a carbon tax was eventually implemented in France. Prime Minister Jean-Marc Ayrault announced the new Climate Energy Contribution (CEC) on September 21, 2013. The tax would apply at a rate of €7/tonne CO2 in 2014, €14.50 in 2015 and rising to €22 in 2016.^[110] In 2018, the carbon tax is at €44.60/tonne.^[111] and is due to increase every year to reach €65.40/tonne in 2020 and €86.20/tonne in 2022.^[112]

After weeks of protests by the "Gilets jaunes" (yellow vests) against the rise of gas prices, French President Emmanuel Macron announced on December 4, 2018, the increase of the carbon tax would not be implemented in 2019 as planned.^[113]

The German ecological tax reform was adopted in 1999. After that, the ecological law of the country was amended twice-in 2000 and in 2003. First of all, the law provided rung-by-rung growth of the taxes on fuel and fossil fuels and laid the foundation for the tax for energy. Only in 2003, after the law's gradual implementation, the amount of emissions reduced by 2.4%, which is 20 million tons of CO2. Thus, the eco-tax is one of the most powerful instruments for climate protection in Germany. The number of workplaces rose by 250,000 jobs.^[114]

In 2004, following a policy review, the Irish Government rejected the introduction of a carbon tax as a policy option.^[115] However, in 2007 a Fianna Fáil-Green Party coalition government was formed, and promised to reconsider the matter. In the 2010 budget the country's first carbon tax was introduced.^[116] The new tax was levied at €15 per tonne of CO2 emissions^[117] (approx. US$20 per tonne).^[118]

The carbon tax applies to kerosene, marked gas oil, liquid petroleum gas, fuel oil, and natural gas. The Natural Gas Carbon Tax does not apply to electricity because the cost of electricity is already included in pricing under the Single Electricity Market (SEM). Similarly, natural gas users are exempt from the tax if they can prove they are using the gas to "generate electricity, for chemical reduction, or for electrolytic or metallurgical processes".^[119] "A partial relief from the tax is granted for natural gas delivered for use in an installation that is covered by a greenhouse gas emissions permit issued by the Environmental Protection Agency. The natural gas concerned will be taxed at the minimum rate specified in the EU Energy Tax Directive, which is €0.54 per megawatt hour at gross calorific value."^[120] Pure biofuels are also exempt.^[121] The Economic and Social Research Institute has estimated the tax will cost between about €2 and €3 a week per household, or about €156 per year:^[122] a survey from the Central Statistics Office reports that Ireland's average disposable income was almost €48,000 in 2007.^[123]

There is concern that the carbon tax may disproportionately affect elderly persons and low-income households. One group, Active Retirement Ireland, proposes that "an extra allowance of €4 per week be made to people in receipt of the State pension for the 30 weeks currently covered by the fuel allowance," they suggest that "home heating oil be added to the categories covered under the Household Benefit Package, which is available to older people in receipt of the State pension".^[124]

The tax is paid by companies to the Collector General. Fraudulent violation is punishable under section 1078 of the Taxes Consolidation Act 1997, which allows for a jail sentence of up to 5 years or a fine of no more than €126,970. Failure to comply with the tax violates section 73 of the Finance Act of 2010. Payment for the first accounting period was due in July 2010.^[125]

The NGO Irish Rural Link^[126] has noted that according to the Irish Economic and Social Research Institute (ESRI) "a carbon tax would weigh more heavily on rural households."^[127] Irish Rural Link claim that experience from other countries has shown that carbon taxation will only succeed if it is part of a comprehensive package of measures, which includes reducing some other taxes which does not appear to be the Government's approach.^[128]

Carbon Tax was introduced in Ireland in the 2010 budget by the Green Party/ Fianna Fáil coalition government at a rate of €15/tonne CO2 which was applied to motor gasoline and diesel and to home heating oil (diesel). Electricity was exempted as electricity generation from fossil fuel power stations was covered under the EU ETS. Solid fuels including coal and turf were also exempted.^[129]

In 2011, the new government coalition of Fine Gael and Labour raised the carbon tax by 33% to €20/tonne. Farmers were granted a tax relief to compensate for this increase.^[130]

The Netherlands initiated a carbon tax in 1990. However, in 1992, it was replaced with a 50/50 carbon/energy tax called the Environmental Tax on Fuels, the taxes are assessed partly on carbon content and partly on energy content. The charge was transformed into a tax and became part of general tax revenues. As such, it fell under the administration of the Ministry of Finance. The general fuel tax is collected on all hydrocarbon fuels. Fuels used as raw materials are not subject to the tax. Tax rates are based 50/50 on the energy and carbon contents of fuels. In 1996, The Regulatory Tax on Energy, another 50/50 carbon/energy tax, was also implemented. The Environmental tax and the regulatory tax are 5.16 Dutch guilder, or NLG, (~$3.13) or per tonne of CO2 and 27.00 NLG (~16.40) per tonne CO2 respectively. Under the general fuel tax, electricity is not taxed, though fuels used to produce electricity are taxable. Energy-intensive industries used to benefit from preferential rates under this tax but the benefit was cancelled in January 1997. Also, since 1997, nuclear power has been taxed under the general fuel tax at the rate of NLG 31.95 per gram of uranium-235.38^{[131][132][133]} The European Environment Agency put out an Executive Summary stating "Although the 5th Environmental Action Programme of the EU in 1992 recommended the greater use of economic instruments such as environmental taxes, there has been little progress in their use since then at the EU level." However, "at Member State level, there has been a continuing increase in the use of environmental taxes over the last decade, which has accelerated in the last 5–6 year...Countries including the Netherlands and the United Kingdom."^[134]

More recently, in 2007, The Netherlands introduced a Waste Fund that is funded by a carbon-based packaging tax. This tax was both used to finance the national Treasury and to finance the activities to help reach the goals of recycling 65% of used packaging by 2012.^[135] The organization Nedvang (Nederland van afval naar grondstof or The Netherlands from waste to value), which was set up in 2005, is the organization supporting producers and importers of packaged goods reaching individual company goals under the Dutch packaging decree. This decree was signed in 2005 and states that producers and importers of packaged goods are responsible for the collection and recycling of that waste, and that at least 65% of that waste has to be recycled. Producers and importers can choose to reach the goals on an individual basis or by joining an organization like Nedvang.^[136]

The Carbon-Based Tax on Packaging was analyzed on behalf of the Ministry of Infrastructure and the Environment and proven to be ineffective.^[137] Therefore, the packaging tax was abolished. Producer responsibility activities for packaging are now financed based on private contracts, that have been declared legally binding.^[138]

In January 1991, Sweden enacted a CO2 tax of 0.25 SEK/kg ($40 per ton at the time, or EUR 27 at current rates) on the use of oil, coal, natural gas, liquefied petroleum gas, petrol, and aviation fuel used in domestic travel. Industrial users paid half the rate (between 1993 and 1997, 25% of the rate), and certain high-energy industries such as commercial horticulture, mining, manufacturing and the pulp and paper industry were fully exempted from these new taxes.

In 1997, the rate was raised to 0.365 SEK/kg ($60 per ton) of CO2.^[139][140] In 2007, the tax was SEK 930 (EUR 101) per ton of CO2.^[141]

The tax is credited with spurring a significant move from hydrocarbon fuels to biomass. As the Swedish Society for Nature Conservation climate change expert Emma Lindberg said, "It was the one major reason that steered society towards climate-friendly solutions. It made polluting more expensive and focused people on finding energy-efficient solutions."^[142][143]

"It increased the use of bioenergy", said University of Lund Professor Thomas Johansson, former director of energy and climate at the UN Development Programme. "It had a major impact in particular on heating. Every city in Sweden uses district heating. Before, coal or oil were used for district heating. Now biomass is used, usually waste from forests and forest industries."

In 1993, the UK government introduced the fuel duty escalator (FDE), an environmental tax on retail petroleum products. The tax was explicitly designed to reduce carbon dioxide emissions in the transport sector. Since carbon is in fixed ratio to the quantity of fuel, the FDE roughly approximated a carbon tax. The transport lobby in the UK was extremely critical of the FDE. The FDE, which was the UK's only "real" carbon tax, failed because of the political criticism it provoked, and the automatic increase of the FDE was cancelled in 1999.^[97] Increases in fuel tax have since been discretionary.

The politically damaging fuel protests in 2000 contributed to the government decision to reduce the real rates of fuel tax. At the time, tax and duty represented more than 75% of the total pump price. In money terms, the past increments of the FDE remain in force, but in real terms, increments have been reduced by the rate of inflation. In 2006, tax represented about ⅔ of the pump price.^[144]

In addition, the UK's Climate Change Levy was introduced in 2001.

Norway introduced a CO2 tax on hydrocarbon fuels in 1991.^[145] The tax started at a high rate of US$51 per tonne of CO2 on gasoline, with an average tax of US$21 per tonne^[146] The tax was also applied to diesel, mineral oil, oil and gas used in North Sea extraction activities.^[147] The International Energy Agency's (IEA) 2001 Review of Norway in the Energy Policies of IEA Countries stated that "since 1991 a carbon dioxide tax has applied in addition to excise taxes on fuel." It is among the highest carbon taxes in the OECD. Carbon taxation is also applied to the production of oil and gas offshore. The IEA estimates for revenue generated by the CO2 tax in 2004 were 7,808 million NOK^[148] (about US$1.3 billion in 2010 dollars).

According to IEA 2005 Review of Norway,^[148] Norway's CO2 tax is its most important climate policy instrument, and covers about 64% of Norwegian CO2 emissions and 52% of total GHG emissions. Some industry sectors have been granted exemptions from the tax to preserve their competitive position. Various studies in the 1990s, and an economic analysis by Statistics Norway, have estimated the effect of the CO2 tax to be a reduction of 2.5–11% of Norwegian emissions under a business-as-usual approach (i.e., the predicted emissions that would have occurred without the tax). However, even with the carbon tax, Norway's per capita emissions rose by 15% between 1991 (when the carbon tax was introduced) and 2008.^[149]

In attempt to reduce CO2 emissions by a larger amount, Norway implemented the first phase of an Emissions Trading Scheme in 2005^[150] and joined the European Union Emissions Trading Scheme (EU ETS) in 2008.^[151] As of 2013, roughly 55% of CO2 emissions in Norway are taxed and emissions that are not covered by a carbon tax are included in the EU ETS.^[151] Certain CO2 taxes are applied to emissions that result from petroleum activities on the continental shelf.^[152] This tax is charged per liter of oil and natural gas liquids produced, as well as per standard cubic meter of gas burnt off or otherwise directly emitted into the air.^[152] However, this carbon tax is considered a deductible operating cost for petroleum production which can therefore be written off to reduce the ordinary taxes paid by oil companies.^[152] In 2013, carbon tax rates were doubled in Norway to a rate of 0.96 NOK per liter/standard cubic meter of mineral oil and natural gas.^[152] As of 2016, the tax rate has been increased to 1,02 NOK per liter or standard cubic meter of oil and natural gas.^[153] Despite this increase, there is intention to reduce the tax in the future if there is a rise in the EU ETS price from the rate it was when the increased carbon tax rate was implemented.^[150] According to the Norwegian Ministry of the Environment, CO2 taxes have been the most important tool for reducing emissions produced by petroleum activities and there is a low level of CO2 emissions per produced oil equivalent.^[154]

In January 2008, Switzerland implemented a CO2 incentive tax on all hydrocarbon fuels, such as coal, oil and natural gas, unless they are used for energy. Gasoline and diesel fuels are not affected by the CO2 tax. The tax is collected by the Swiss Federal Customs Administration. It is an incentive tax because it is designed to promote the economic use of hydrocarbon fuels.^[155] The tax amounts to CHF 12 per tonne CO2, which is the equivalent of CHF 0.03 per litre of heating oil (US$0.108 per gallon) and CHF 0.025 per m3 of natural gas (US$0.024 per m3).^[156] This tax comes from Switzerland's 1999 Federal Law on the Reduction of CO2 (CO2 Law). Although Switzerland prefers to rely on voluntary actions and measures to achieve emissions reductions, the CO2 Law mandated the introduction of a CO2 tax if voluntary measures proved to be insufficient.^[157] In 2005, the federal government decided that additional measures were needed to achieve emissions reductions and meet Kyoto Protocol commitments of an 8% reduction in greenhouse gas emissions below 1990 levels between 2008 and 2012.^[158] In 2007, the CO2 tax was approved by the Swiss Federal Council, coming into effect 2008.^[156] In 2010, the highest tax rate will be CHF 36 per tonne of CO2 (US$34.20 per tonne CO2).^[159]

Companies are allowed to exempt themselves from the tax by participating in a Swiss cap-and-trade emissions trading scheme where they voluntarily commit to legally binding targets to reduce their CO2 emissions.^[160] Under this scheme, emission allowances are given to companies for free, and each year emission allowances equal to the amount of CO2 emitted must be surrendered by the company. Companies are allowed to sell or trade excess permits. However, should a company fail to surrender the correct amount of allowances, they must pay the CO2 tax retroactively for each tonne of CO2 emitted since the exemption was granted.^[158] About 400 companies take part in trading CO2 emission credits under this program. In 2009, for the second year in a row, the companies returned enough credits to the Swiss government to cover their CO2 emissions for the year. The 2009 report shows that companies emitted only about 2.6 million tonnes of CO2, falling well below the total permissible quantity of 3.1 million tonnes.^[161] The Swiss carbon market still remains fairly small, with few emissions permits being traded. Swiss domestic law tends to favor the use of a CO2 tax to achieve emissions reductions and this preference for taxes combined with an immature carbon market could partially explain why Switzerland has not yet joined the European Union Emission Trading Scheme (EU ETS).^[162]

The tax is revenue neutral, and its revenues are redistributed proportionally to companies and to the Swiss population. For example, if the population bears 60% of the tax burden, they will receive 60% of the redistribution. For companies, revenues will be redistributed to all companies, except those who chose to exempt themselves from the tax through the cap-and-trade program.^[159] The revenue is given to the companies in proportion to the total payroll of their employees and is distributed through an AHV compensation fund (Federal Old Age and Survivors' Insurance) that pays the relevant amount of revenue to the company.^[163] The revenues from the tax that were paid by the Swiss population are redistributed equally to all Swiss residents through health insurance companies and a deduction on their insurance premium.^[159][163] In June 2009, the Swiss Parliament decided to allocate about one-third of the revenue from the carbon tax to a 10-year building program for climate-friendly building renovations. This program promotes building renovations, the use of renewable energies, the utilization of waste heat, and building engineering.^[159]

As part of the early-redistribution program decided by the Swiss Federal Council in 2009, the tax revenue from 2008, 2009, and 2010, are being distributed in 2010.^[159] In 2008 alone, the tax of CHF 12 per tonne of CO2 raised around CHF 220 million (US$209 million) in revenue. As of June 16, 2010, a total of around CHF 360 million (US$342 million) have become available for distribution to the Swiss population and economy.^[163] It is estimated that in 2010, at the highest tax rate of CHF 36 per tonne of CO2, the revenue from the tax will be about CHF 630 million (US$598 million). Out of the projected CHF 630 million, CHF 200 million (US$190 million) will be allocated for the building program and the remaining CHF 430 million (US$409 million) will be redistributed in 2010 to the population and the economy.^[159] The International Energy Agency (IEA) commends Switzerland's CO2 tax for its excellent design and notes that the recycling of the tax revenues to all citizens and enterprises is "sound fiscal practice".^[158]

Since 2005, transport fuels in Switzerland have been subjected to the Climate Cent Initiative surcharge—a surcharge of CHF 0.015 per litre on gasoline and diesel (US $0.038 per gallon) which will remain in place until the end of 2012. However, this surcharge can be supplemented with a CO2 tax on transport fuels if emissions reductions are not satisfactory. In their 2007 review, the IEA recommended that Switzerland implement a CO2 tax on transport fuels or increase the Climate Cent surcharge to better balance the high costs of meeting emissions reductions targets across sectors.^[164]

Switzerland is currently on track to meet its Kyoto Protocol commitment of an 8% reduction in greenhouse gas emissions below 1990 levels between 2008 and 2012. The combination of the CO2 tax and other voluntary measures by businesses and private individuals is enabling Switzerland to achieve these reduction goals.^[165]

In 1997, Costa Rica imposed a 3.5 percent carbon tax on hydrocarbon fuels.^[166] A portion of the funds generated by the tax go to "Payment for Environmental Services" (PSA) program which gives incentives to property owners to practice sustainable development and forest conservation.^[167] Approximately 11% of Costa Rica's national territory is protected by the plan.^[168] The program now pays out roughly $15 million a year to around 8,000 property owners.^[169]

In the 2008 Canadian federal election, a carbon tax proposed by Liberal Party leader Stéphane Dion, known as the Green Shift, became a central issue in the campaign. It would have been revenue-neutral, with increased taxation on carbon being balanced by tax cuts for individual citizens. However, it proved to be unpopular and contributed to the defeat of Liberal Party with its worst share of the popular vote since Confederation.^{[170][171][172][173]} By contrast, the Conservative party, who won the election, had promised to "develop and implement a North American-wide cap-and-trade system for greenhouse gases and air pollution, with implementation to occur between 2012 and 2015."^[174]

In 2018, Canada passed the Greenhouse Gas Pollution Pricing Act implementing revenue-neutral carbon levy starting in 2019.^[175][176] This fulfils a campaign pledge that Justin Trudeau made in 2015, before being elected as Prime Minister of Canada.^[176] The Greenhouse Gas Pollution Pricing Act will apply only to provinces which do not have provincial carbon pricing systems meeting the federal requirements.^[176] In each province, the levied funds will be redistributed to citizens (households).^[176]

The Canadian province of Quebec became the first in Canada to introduce a carbon tax.^[177][178] The tax was to be imposed on energy producers starting October 1, 2007, with revenue collected used for energy-efficiency programs including public transit. The tax rate for gasoline is $CDN0.008 per liter, or about $3.50 per tonne of CO2 equivalent.^[179]

On February 19, 2008, the province of British Columbia announced its intention to implement a carbon tax of $10 per tonne of Carbon dioxide equivalent (CO2e) emissions (2.41 cents per litre on gasoline) beginning July 1, 2008, making BC the first North American jurisdiction to implement such a tax. The tax will increase each year after until 2012, reaching a final price of $30 per tonne (7.2 cents per litre at the pumps).^[180][181] Unlike previous proposals, legislation will keep the pending carbon tax revenue neutral by reducing corporate and income taxes at an equivalent rate.^[182] Also, the government will also reduce taxes above and beyond the carbon tax offset by $481 million over three years.^[180] In January 2010, the carbon tax was applied to biodiesel. Before the tax actually went into effect, the government of British Columbia sent out "rebate cheques" from expected revenues to all residents of British Columbia as of December 31, 2007.^[183] In January 2013, the carbon tax was collecting about $1 billion each year which was used to lower other taxes in British Columbia. Terry Lake, the minister of the environment of British Columbia, said "It makes sense, it's simple, it's well accepted."^[184]

The British Columbia revenue-neutral carbon tax is based on the following principles:

Following implementation many Canadians concluded that the carbon tax generally benefitted the British Columbian economy, in large part because its revenue neutral feature did indeed reduce personal income taxes.^[186] However some industries complained loudly that the tax had harmed them, notably cement manufacturers and farmers.^[187] Nevertheless, the tax generated sufficient praise to attract broad attention in the United States and elsewhere from those seeking an economically efficient way of reducing the emission of greenhouse gases without hurting economic growth.^[188]

In July 2007, Alberta enacted the Specified Gas Emitters Regulation, Alta. Reg. 139/2007,^[189] (SGER). This carbon tax^[190][191] requires a $15/tonne contribution be made to the "Climate Change and Emissions Management Fund" (CCEMF) by companies that emit more than 100,000 tonnes of greenhouse gas annually to either reduce their CO2 emissions per barrel by 12 percent, or buy an offset in Alberta to apply against their total emissions.^{[192][193][194]} In January 2016, the contribution required by large emitters to the CCEMF was increased by the provincial government to $20/tonne.^[195] The tax will fall most heavily on oil companies and coal-fired electricity plants. It intends to give companies a real incentive to lower emissions while fostering technology that makes the job easier. The plan only covers the largest companies that produce 70% of Alberta's emissions.^[194] There are concerns that this is a serious omission because the smallest energy producers are often the most casual about emissions and pollution.^[194] The carbon tax is currently $20 per tonne.^[196] Because Alberta has the highest greenhouse gas emissions in Canada the majority of Albertans are strongly opposed to a nationwide carbon tax. There is a fear that a nationwide carbon tax would cause Alberta's economy to suffer significantly more in proportion to other provinces. Alberta is also opposed to a Cap and Trade system it fears the trades will pull revenue out of the province, a fear not to be dismissed. Alberta's local carbon price allows the money to stay within Alberta.^[197]

On November 23, 2015, the Alberta government announced a new carbon tax scheme very similar to British Columbia's in that it will be applied to the entire economy. All businesses and residents will pay a carbon tax based upon the carbon dioxide equivalent emissions, including the burning of wood and biofuels. The tax will come into force in 2017 with a price of $20 per tonne. The price will increase to $30 per tonne in 2018 and increase thereafter by the rate of inflation plus 2%.

Also announced will be the reduction of coal-powered electricity generation. Currently, coal provides 51% of the power in the province. The target is to eliminate coal generation by 2030. Renewable energy production (primarily wind and solar in Alberta) is targeted at 30% of generating capacity by 2030.

The effect on consumers will be an increase of 6.73¢ per litre for gasoline and $1.517 per gigajoule for natural gas.^[198] Because it is primarily generated from burning hydrocarbons, electricity prices are also expected to rise, although the exact amount is currently unknown. The total personal cost is estimated to be about $120 per capita, based on a $300 per household cost. Rebates will be provided to low income earners and temporary rebates provided to exporters to offset competitive disadvantages.^[199]

According to the Carbon Tax Center,^[200] the United States is one of the few large and industrialized nations on Earth that does not implement a carbon tax. One simple solution being considered is to implement a federal carbon emissions tax, instead of relying on states to enforce their own. According to economists a tax would be the simplest and the easiest way to reduce emissions since, primarily, it seems like a plan both parties can get behind since it would not impose strict regulations on business, instead allowing the industries to self regulate, while also a showing that the government is taking steps to protect the environment. Furthermore, a tax would lead both producers and consumers to adjust their respective habits accordingly, and in ways that may become more efficient.^[201] On July 23, 2018 Congressman Carlos Curbelo (R-FL) introduced H.R. 6463,^[202] the "Modernizing America with Rebuilding to Kick-start the Economy of the Twenty-first Century with a Historic Infrastructure-Centered Expansion (MARKET CHOICE) Act." There is also a national movement called Citizens' Climate Lobby to create support across parties to put a national price on carbon. Also, Americans for Carbon Dividends is building support for the Baker-Shultz Carbon Dividends Plan, and is supported by several large companies including First Solar, American Wind Energy Association, Exxon Mobil, BP, Royal Dutch Shell, and Total SA.^[203]

Internal price on carbon

Although the United States does not currently implement a carbon tax, many American corporations have set the precedent on setting an “internal price on carbon”. Companies calculate this internal price to assess the risk value of future projects when making economic investment decisions. Companies usually assess a higher internal price when i) the company emits large amounts of CO2, and ii) when the company projects further into the future.^[204] Oil companies usually have assets (factories, refineries) that have a long lifespan and that can be affected by energy policies in the future; the products and assets of consumer-goods companies are mostly influenced by current policies, so their carbon prices are usually lower.

Oil companies like Shell and ConocoPhillips apply this carbon price to current and future operations; the motivation is to "apply the carbon price as much to spur mitigation as to quantify risks".

Timeline for implementing social cost of carbon

The US Environmental Protection Agency has recently removed their page regarding the social cost of carbon since the new Trump administration has been installed.^[205] EPA Director Scott Pruitt's skepticism towards human contributions to climate change has led to a decreased emphasis towards advancing climate change policies. Several administrative advisers have stated that the social cost should be reduced to zero (currently at $36 per ton of carbon dioxide). A possible reduction or elimination of the social carbon cost would lead to the overhaul of dozens of climate regulations established in previous administrations.

Colorado

In November 2006, voters in Boulder, Colorado passed what is said to be the first municipal carbon tax. It is a tax on electricity consumption (utility bills) with deductions for using electricity from renewable sources (primarily Xcel's WindSource program). The goal is to reduce carbon emissions to those outlined in the Kyoto Protocol; specifically to reduce their emissions by 7% below 1990 levels by 2012.^[206] Tax revenues are collected by Xcel Energy and are directed to the city's Office of Environmental Affairs to fund programs to reduce community-wide greenhouse gas emissions.^[207]

Boulder's Climate Action Plan (CAP) tax is expected to raise $1.6 million in 2010. The tax was increased to a maximum allowable rate by voters in 2009 to meet CAP goals. Currently the tax is set at $0.0049 /kWh for residential users (ave. $21 per year), $0.0009 /kWh for commercial (ave. $94 per year), and $0.0003 /kWh for industrial (ave. $9,600 per year). The revenues from the tax are expected to decrease over time as businesses and residents reduce their energy use and begin to use more solar and wind power. The tax was renewed by voters on November 6, 2012.^[206]

As of 2015, the Boulder carbon tax is estimated to reduce carbon output by over 100,000 tons per year, and allows the city to collect $1.8 million in revenue that is interjected back into the city. Those funds are infused back into the community by providing bike lanes, energy efficient solutions, rebates for business and homeowners to further invest in green energy, and community based programs to further still bring awareness to the movement ^[208] The tax is Boulder's way of initiating a future global movement. Because of Boulder's progressiveness and willingness to adapt, this was a fantastic opportunity to trial-run this type of program. It leverages all forms of individual - residential, commercial, and industrial. This results in a low surcharge that has been generally well received. The average household pays just US$21 towards the tax each year, while the average business pays just $94 per year.^[209] The success of the program has provided a stable and efficient means of carbon tax implementation and enforcement that shows its long-term sustainability in all United States markets.

California

In May 2008, the Bay Area Air Quality Management District, which covers nine counties in the San Francisco Bay Area, passed a carbon tax on businesses of 4.4 cents per ton of CO2.^[210]

In 2006, the state of California, passed AB-32 (Global Warming Solutions Act of 2006), which requires California to reduce greenhouse gas emissions. To implement AB-32, the California Air Resources Board proposed a carbon tax, but has yet to reach agreement with the Western States Petroleum Association which represents the refineries in the state. The WSPA holds that AB-32 only allows a carbon tax to cover administrative costs.^[211]

Maryland

In May 2010, Montgomery County, Maryland passed the nation's first county-level carbon tax.^[212] The legislation required payments of $5 per ton of CO2 emitted from any stationary source emitting more than a million tons of carbon dioxide during a calendar year.^[213] There is only one source of emissions fitting the criteria laid out by the council, an 850 megawatt coal-fired power plant owned by Mirant Corporation. The tax was expected to raise between $10 million and $15 million for the county, which faced a nearly $1 billion budget gap.^[214] The law provided for half of revenue to go toward creating a low interest loan plan for county residents to invest in residential energy efficiency upgrades.^[213] The County's energy supplier buys its energy at auction, so Mirant would have to sell its energy at market value, which meant no discernible increase in energy costs would be felt by the county's residents. In June 2010, the Mirant Corporation sued the county to stop the tax.^[215] In June 2011 the Federal Court of Appeals ruled that the tax was a fee imposed "for regulatory or punitive purposes" rather than a tax, and therefore could be challenged in court.^[216] The County Council repealed the fee in July 2012.^[217]

Washington

In 2016, a group of climate activists put an initiative for a revenue-neutral carbon tax on the November ballot in Washington State. If approved by voters, it would have imposed a tax on carbon dioxide emissions and used that revenue to decrease the state's sales tax, the business tax, and expand the state's version of the earned income tax credit for low-income workers.

Greg Mankiw, head of the Council of Economic Advisers under the George W. Bush administration, economic adviser to Mitt Romney for his 2012 presidential campaign and economics professor at Harvard University since 1985, has been advocating for increased carbon/oil taxation since at least 1999.^[218] In 2006, he founded the Pigou Club of economists advocating for Pigovian taxes, a carbon tax chiefly among them. In the club's manifesto, he writes that "[h]igher gasoline taxes, perhaps as part of a broader carbon tax, would be the most direct and least invasive policy to address environmental concerns."^[219]

In 1979, economist Milton Friedman expressed support for the idea of a carbon tax in an interview on The Phil Donahue Show, saying "...the best way to [deal with pollution] is to impose a tax on the cost of the pollutants emitted by a car and make an incentive for car manufacturers and for consumers to keep down the amount of pollution."^[220]

In 2001, environmental scientist Lester Brown, founder of the Worldwatch Institute and founder and president of the Earth Policy Institute, outlined a detailed "tax shifting" structure which would not lead to an overall higher tax level: "It means reducing income taxes and offsetting them with taxes on environmentally destructive activities such as carbon emissions, the generation of toxic waste, the use of virgin raw materials, the use of non-refillable beverage containers, mercury emissions, the generation of garbage, the use of pesticides, and the use of throwaway products... activities that should be discouraged by taxing.""^[221] Brown subsequently added that such a tax shift would amount to an "honest market," explaining, "The key to restructuring the economy is the creation of an honest market, one that tells the ecological truth."^[222] In 2011 he estimated the cost of such a tax shift, including the effects of better technology, the use of renewables and "updating the concept of national security."^[223]

Former US 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."^[224]

NASA climatologist James E. Hansen has argued in support of a carbon tax.^[225][226]

Commencing in North America, the nonprofit Citizens' Climate Lobby has been advocating for carbon tax legislation (specifically a progressive fee and dividend model with revenue returned to citizens in the form of a check or rebate). The organization has about 165 chapters in the United States, Canada, and several other countries including Bangladesh and Sweden.^[227]

Monica Prasad, a Northwestern University sociologist, wrote about Denmark's carbon tax in The New York Times in 2008.^[228] In her view, the Danish carbon tax served as an example of how to reduce emissions in the US. Prasad argued that a critical component for Denmark's success in reducing carbon emissions from 1990–2005 was that the tax revenues from the carbon tax were dedicated to subsidies for firms to use for alternative, environmentally cleaner sources of energy.

According to economist Laura D'Andrea Tyson, "The beauty of a carbon tax is its market-based simplicity. Economists since Adam Smith have insisted that prices are by far the most efficient way to guide the decisions of producers and consumers. Carbon emissions have an "unpriced" societal cost in terms of their deleterious effects on the earth's climate. A tax on carbon would reflect these costs and send a powerful price signal that would discourage carbon emissions." She listed several prominent economists and political figures that have supported carbon taxes.^[229]

Former US Vice President Al Gore strongly backed a carbon tax in his book, Earth in the Balance. In 2000, when Gore ran for president, one commentator labeled Gore's carbon tax proposal a "central planning solution" harking back to "the New Deal politics of his father."^[230] Former United States Congressional Representative Bob Inglis (R-South Carolina) heads the Energy and Enterprise Initiative at George Mason University which is making the conservative case for climate legislation through support for a carbon tax.^[231]

An alternative government policy to a carbon tax is a cap on greenhouse gas (GHG) emissions. Emission levels of GHGs are capped and permits to pollute are freely allocated (called "grandfathering") or auctioned to polluters. Auctioning permits has significant economic advantages over grandfathering. In particular, auctioning raises revenues that can be used to reduce distortionary taxes and improve overall efficiency.^[249] A market may be allowed for these emission permits so that polluters can trade some or all of their permits with others (cap-and-trade). A hybrid instrument of a cap and carbon tax can be made by creating a price-floor and price-ceiling for emission permits.^[22] A carbon tax can also be implemented concurrently with a cap.^[43]

Unlike a cap system with grandfathered permits, a carbon tax raises revenues. If the revenues are used to reduce other distortionary taxes, this can improve the efficiency of the tax. On the other hand, a cap with grandfathered permits can have an efficiency advantage of being applied to all industries. This provides an equal incentive at the margin for all polluters to reduce their emissions. This is an advantage over a tax that exempts or has reduced rates for certain sectors.^[249]

Both carbon taxes and permit systems (sometimes known as "Cap and Trade") aim to reduce the total quantity of carbon emissions by creating a price for emitting CO2 pollution, but they achieve this goal in distinctly separate ways.^[250] While carbon taxes dictate the price that will be paid for each unit of pollution, permit systems set a specific quantity of CO2 that all applicable entities will be held to and divides this total amount into tradable permits.^[250] In the absence of uncertainty these two systems will achieve the same effect and result in the efficient market quantity of CO2 and price charged per unit of CO2 emitted.^[250][251] In the case of environmental uncertainty, that is when the environmental damages of each unit of CO2 cannot be accurately calculated, a permit system may be more advantageous in order to limit total quantity and thus potential damages.^[251] In the case of uncertainty regarding the costs of CO2 abatement for firms, a tax is preferable.^{[251][250][252]} The abatement uncertainty issue was illustrated in 2005 by the first phase of the European Union Emissions Trading System (cap and trade).^{[253][250][252]} In this program, the initial allocation of permits was too great as the EU did not accurately assess the CO2 reduction capabilities of the various firms it regulated, and thus firms simply reduced their emissions to their allotted quantity without the purchase of any additional permits.^[250] This drove the permit prices to nearly zero two years after the program began, crashing the system and commanding reform and permit allocation refinement that would eventually manifest itself in the current European Union Emissions Trading System (Phase 3)^[250][254]

A 2018 survey of leading economists found that not a single one of the surveyed economists disagreed with the assertion, "Carbon taxes are a better way to implement climate policy than cap-and-trade."^[6]

Both cap-and-trade and carbon taxes give polluters a financial incentive to reduce their GHG emissions. Carbon taxes provide certainty regarding emission prices, while a cap provides certainty regarding emissions quantity.^[255] In a literature assessment, Fisher et al.. (1996:430) concluded that the choice between an international quota (cap) system, or an international carbon tax, remained ambiguous.^[48] Lu et al. (2012) compared a carbon tax, an emission trading, and command-and-control regulation at the industrial level. Their abstract concludes that market-based mechanisms would perform better than emission standards in achieving emission targets without affecting industrial production.^[256]

James E. Hansen argued in his book (Storms of My Grandchildren) and in an open letter to then President Obama, that carbon emissions trading would only make money for banks and hedge funds and allow 'business-as-usual' for the chief carbon-emitting industries.^[257][226]