Carbon Tax vs. Carbon Credits: Which is More Effective for Indonesia?

1. Introduction: The Climate Crisis and the Urgency of Carbon Economic Instruments in Indonesia

Global climate change has become a central issue demanding immediate attention and action from all countries, including Indonesia. As an archipelagic nation with a long coastline and rich biodiversity, Indonesia is highly vulnerable to the negative impacts of climate change, such as rising sea levels, extreme weather, and disruptions to the agricultural and fisheries sectors. Recognizing this urgency, Indonesia has demonstrated its commitment to contributing to global mitigation efforts. This commitment is outlined in its Nationally Determined Contribution (NDC), which targets a reduction in Greenhouse Gas (GHG) emissions by 29% through its own efforts, and potentially up to 41% with international support by 2030, compared to a business-as-usual scenario.  

Achieving this ambitious NDC target requires a comprehensive set of policies and instruments. One approach gaining increasing attention is the implementation of carbon economic instruments. The Indonesian government has laid the groundwork for these instruments through Presidential Regulation (Perpres) No. 98 of 2021 concerning the Implementation of Carbon Economic Value (NEK) for Achieving Nationally Determined Contribution Targets and Controlling Greenhouse Gas Emissions in National Development. This regulation serves as the legal basis for various carbon pricing mechanisms, including carbon taxes and carbon trading (often associated with carbon credits). The issuance of this NEK regulation indicates a close link between Indonesias international commitments under the Paris Agreement and the formulation of domestic policies. Without such global pressure and commitment, the drive to implement complex carbon economic instruments might not be as strong as it is today.  

The NEK framework itself is designed as an ambitious umbrella policy, encompassing not just one, but a variety of mechanisms such as carbon trading, levies on carbon (which form the basis of carbon taxes), results-based payments, and other mechanisms adaptable to scientific and technological advancements. This comprehensive approach reflects an understanding that there is no single solution to address the complex challenge of carbon emissions. However, on the other hand, this ambition also brings significant implementation challenges, requiring strong cross-sectoral coordination and capacity building at various levels.  

This article aims to analyze in more depth two main instruments within the NEK framework: carbon tax and carbon credits (through the carbon trading mechanism). The analysis will focus on research, discussion, and the specific context of Indonesia, to assess which of these two instruments, or a combination thereof, has the potential to be more effective in helping Indonesia achieve its climate targets while supporting sustainable national development.

2. Dissecting the Concept: What is a Carbon Tax?

A carbon tax is a fiscal instrument designed to internalize the external costs of carbon emissions. Fundamentally, a carbon tax is levied on GHG emissions or the carbon content of fuels. Its primary goal is to provide an economic price signal to emitters (polluters). With an additional cost on emissions, polluters are expected to be encouraged to make more environmentally friendly decisions, whether by reducing emission-generating activities, investing in cleaner technologies, or, if not, they must pay a tax on the emissions they produce. The imposition mechanism can be a direct tax on the amount of emissions released or a tax imposed on goods or activities that generate emissions, such as the use of fossil fuels.  

Implementation in Indonesia

In Indonesia, the main legal basis for the implementation of a carbon tax is Law No. 7 of 2021 concerning the Harmonization of Tax Regulations (UU HPP). This regulation is part of a broader tax reform and aims to support the governments efforts to achieve GHG emission reduction targets.  

• Planned Tariff and Tax Objects: The Indonesian government has set an initial planned carbon tax rate of IDR 30,000 per ton of CO2​e (carbon dioxide equivalent). This rate, if converted, is around USD 2 per ton of CO2​e. For comparison, this rate is lower than in developed countries like Sweden (USD 127.25 per ton CO2​e), but higher than some other countries like Ukraine (USD 0.76 per ton CO2​e). The targeted objects of the carbon tax include fossil fuels (such as coal, diesel, and gasoline) and carbon emissions generated from various activities, including industrial/factory activities and motor vehicles. For the initial implementation phase, coal-fired Steam Power Plants (PLTU) are the main focus.  

• Imposition Mechanism: Indonesia plans to implement the carbon tax through a scheme known as "cap and tax". Under this scheme, the government will set an emission cap for certain entities. If an entity produces emissions exceeding this limit and cannot or chooses not to purchase additional emission permits (e.g., from a carbon exchange), then the excess emissions will be subject to a carbon tax. Additionally, there is also discussion of imposing a direct tax on carbon emissions. This "cap and tax" mechanism is interesting because it inherently creates a bridge between the carbon tax instrument and the carbon trading mechanism. Affected entities have a choice between paying the tax or participating in the carbon market to meet their obligations, which theoretically can drive cost efficiency in emission reductions.  

• Implementation Status and Postponement: The initial plan for implementing the carbon tax, particularly for coal-fired PLTUs, was scheduled for 2022. However, this implementation has been postponed, and is now targeted for broader application starting in 2025. This postponement is not without reason. Several contributing factors include the need to mature technical planning, including implementation mechanisms and the utilization of collected funds. Furthermore, infrastructure readiness, especially an accurate and reliable Measurement, Reporting, and Verification (MRV) system, is crucial and requires significant time and investment. There are also allegations that potential conflicts of interest from various parties have influenced the dynamics of this policys implementation. This delay signals the complexity faced by the government in launching a new policy with significant impacts on the economy and industry, and indicates a process of negotiation and adjustment to accommodate various considerations. The low initial proposed tariff of IDR 30,000 per ton of CO2​e also raises questions about its significance in driving massive changes in industrial behavior. Although it can be considered an initial step or a "soft start" to familiarize the market, its long-term effectiveness will heavily depend on the political will to periodically adjust the tariff to remain relevant to emission reduction goals.  

Potential Advantages of Carbon Tax

The implementation of a carbon tax offers several potential benefits, both generally and in the specific context of Indonesia:

1. Reducing Carbon Emissions and Promoting Green Technology: By providing a financial disincentive for emissions, a carbon tax is expected to encourage companies and individuals to reduce fossil fuel consumption and switch to cleaner, more environmentally friendly technologies.  

2. Source of Environmental Funding and State Budget (APBN): Revenue generated from the carbon tax can become a new source of funding for the government. This fund ideally can be reallocated to support environmental projects, research and development of renewable energy, and other climate change adaptation and mitigation programs. The potential state revenue from carbon tax in Indonesia is estimated to be quite significant.  

3. Improving Air Quality: Reducing carbon emissions, especially from burning fossil fuels, will directly contribute to improved air quality, which has a positive impact on public health.  

4. Providing Carbon Price Certainty: Unlike carbon credit prices in the market which can fluctuate, a carbon tax sets the emission price directly, thus providing cost certainty for economic actors in their investment and operational planning.

Potential Disadvantages and Challenges of Carbon Tax

Despite its many potentials, the implementation of a carbon tax also faces several disadvantages and challenges:

1. Increase in Prices of Goods and Services: One of the most frequently feared impacts is the potential increase in the prices of goods and services as a result of increased company operational costs. This can be regressive, meaning its impact is more felt by low-income groups.  

2. Determining the Optimal Tariff: Setting the "right" carbon tax tariff is a major challenge. A tariff that is too low may not be effective in encouraging emission reductions, while a tariff that is too high can excessively burden the economy and reduce industrial competitiveness.  

3. MRV Infrastructure Readiness: The effectiveness of a carbon tax heavily depends on the availability of an accurate, transparent, and accountable MRV system to measure and report emissions. The development and operationalization of this system require adequate investment and technical capacity.  

4. Resistance from Industry: Carbon-intensive industries, which will be the main subjects of this tax, are likely to show resistance due to potential cost increases. Dialogue and fair transition mechanisms are needed to address this.  

5. Risk of Carbon Leakage: If a carbon tax is implemented domestically without being balanced by similar policies in other countries or a carbon border adjustment mechanism, there is a risk that companies will move their production to countries with looser emission regulations.

3. Dissecting the Concept: What are Carbon Credits (Carbon Trading)?

Carbon credits, in the context of carbon trading, are market-based instruments representing the right to emit a certain amount of carbon emissions, usually equivalent to one ton of CO2​e. These credits can also represent a verified reduction or removal of GHG emissions from the atmosphere through specific projects. This concept forms the basis of carbon trading mechanisms aimed at achieving emission reduction targets efficiently.  

Basic Mechanisms of Carbon Trading

There are two main relevant mechanisms in carbon trading:

1. "Cap-and-Trade" System: In this system, the government or regulatory authority sets an upper limit (cap) on total emissions for a specific sector or group of industries over a certain period. This emission limit is then distributed to each entity in the form of emission allowance allocations. Companies that can reduce their emissions below their allocated allowance can sell their excess emission allowances as carbon credits to other companies whose emissions exceed their allocation or who need additional allowances. In Indonesia, this mechanism is closely related to the Technical Approval for Emission Ceilings for Business Actors (PTBAE-PU), where the traded carbon units are unused emission allocations.  

2. Carbon Offset System: This mechanism involves carbon credits generated from projects that actively reduce or absorb GHG emissions from the atmosphere. Examples of offset projects include reforestation and afforestation activities, renewable energy development (such as solar or wind power plants replacing fossil fuel power plants), energy efficiency improvements, waste-to-energy management, or sustainable agricultural practices that enhance carbon sequestration in soil. In Indonesia, credits from these offset projects are known as Greenhouse Gas Emission Reduction Certificates (SPE-GRK). SPE-GRK can originate from nature-based projects, such as in the Agriculture, Forestry, and Other Land Use (AFOLU) sector, as well as from technology-based projects in the energy, waste, and industrial sectors.  

Implementation in Indonesia

Indonesia has taken significant steps in developing the infrastructure and regulatory framework for carbon trading.

• Legal Basis: The main foundation for organizing carbon trading in Indonesia is Presidential Regulation No. 98 of 2021 concerning the Implementation of Carbon Economic Value. This regulation is further elaborated through technical regulations, one of which is the Minister of Environment and Forestry Regulation (Permen LHK) No. 21 of 2022 concerning the Governance of Carbon Economic Value Implementation.  

• Indonesia Carbon Exchange (IDXCarbon):
  
  

• As a concrete manifestation of carbon trading implementation, the Indonesia Carbon Exchange, known as IDXCarbon, was officially launched on September 26, 2023. The operation of IDXCarbon is carried out by PT Bursa Efek Indonesia (BEI) and is supervised by the Financial Services Authority (OJK).  

• The regulation and supervision of carbon trading through the exchange are detailed by OJK through several regulations, namely OJK Regulation (POJK) No. 14 of 2023 concerning Carbon Trading Through Carbon Exchanges and OJK Circular Letter (SEOJK) No. 12/SEOJK.04/2023 concerning Procedures for Organizing Carbon Trading Through Carbon Exchanges.  

• Carbon Units traded on IDXCarbon include PTBAE-PU (from the cap-and-trade scheme) and SPE-GRK (from offset projects). Interestingly, in POJK 14/2023 Article 3, Carbon Units are categorized as "Securities" (Efek). This classification has significant implications for the market structure and applicable regulations. With the status of Securities, carbon trading is subject to the established legal framework of the capital market and supervised by OJK, with BEI as the exchange organizer. This approach provides a level of transparency, investor protection, and governance expected to follow capital market standards. However, this also differs from practices in some other countries that treat carbon units as commodities. It needs to be observed how this capital market regulatory framework will adapt to the unique characteristics of carbon units whose intrinsic value is linked to environmental goals and emission reductions.  

• To become a carbon exchange organizer, there is a substantial minimum paid-up capital requirement of IDR 100 billion, and this capital cannot be sourced from loans. This requirement indicates the governments expectations regarding the scale of operations and the seriousness of organizing the carbon exchange in the future.  

• Initial trading data on IDXCarbon shows emerging market activity, although the volume is still developing. By the end of 2024, IDXCarbon reportedly had registered participation from 112 entities and traded over 1.6 million tons of CO2​e with a total transaction value exceeding IDR 77.9 billion. There are 8 registered SPE-GRK projects. However, the market price of carbon units showed a downward trend from the initial launch price, with the price at the end of December 2024 around IDR 58,000 per ton. This development indicates that IDXCarbon, despite being supported by strong regulations and great ambition, is still in the early stages of building liquidity and stable price discovery. Its success will heavily depend on increased demand driven by compliance policies (e.g., from a strict cap-and-trade scheme or integration with carbon tax) and the availability of high-quality carbon credit supply.  

Table 1: Overview of Initial Performance of Indonesia Carbon Exchange (IDXCarbon)

Note: Data may change over time. This table presents a general overview based on information available up to early 2025.

Potential Advantages of Carbon Credits

Carbon trading mechanisms, if well-designed and implemented, can offer several advantages:

1. Flexibility and Cost Efficiency: Provides flexibility for companies to choose the most cost-effective way to meet emission reduction targets, whether by making internal investments to reduce emissions or buying carbon credits from other entities that can reduce emissions at a lower cost.  

2. Encouraging Green Innovation and Investment: Creates market incentives for the development and implementation of clean technologies, renewable energy projects, and sustainable forestry and land-use practices that can generate carbon credits.  

3. Revenue Potential: Can be a source of income for the state (through the sale of initial emission allowances) and for entities that successfully develop emission reduction projects and sell their carbon credits.  

4. Increasing Awareness and Participation: Encourages increased environmental awareness and participation from various parties, including the private sector, in climate change mitigation efforts.  

5. Strengthening International Cooperation: Can facilitate technology transfer and climate finance through cross-border carbon trading mechanisms, as well as strengthen international cooperation in addressing climate change.  

Potential Disadvantages and Challenges of Carbon Credits

However, carbon trading systems also have potential disadvantages and face various challenges:

1. Price Volatility and Market Liquidity: The price of carbon credits in the market can be highly volatile, influenced by various supply and demand factors, as well as market sentiment. A less liquid market can also hinder efficient price discovery. Initial data from IDXCarbon showing a price decrease from the launch level indicates this challenge.  

2. Risk of Political Interference: The effectiveness of the carbon market can be disrupted by inappropriate political interference, which can affect the setting of emission "caps" or price stability.  

3. Effectiveness of Emission Reduction: The effectiveness of a cap-and-trade system in reducing overall emissions heavily depends on how strict the "cap" is set. If the "cap" is too loose, significant emission reductions may not be achieved. Similarly, if the market is flooded with low-quality or non-"additional" offset credits, the environmental integrity of the system can be questioned.  

4. Need for Strong MRV and Oversight Systems: The credibility of the carbon market heavily relies on strong, transparent, and independent MRV systems to ensure that claimed emission reductions actually occur and are verifiable. Without strict oversight and law enforcement, the carbon market is vulnerable to fraud and "greenwashing" practices. This is a crucial point because the quality of traded SPE-GRK greatly determines market confidence. Indonesia needs to ensure that all projects generating SPE-GRK meet international standards and are verified by competent institutions, especially if targeting participation from international markets.  

5. Lack of Awareness and Capacity: Low awareness and understanding of carbon trading mechanisms among industry players and other stakeholders can hinder their participation and commitment to emission reduction efforts.  

6. Regulatory and Roadmap Implementation Challenges: Although the basic legal framework exists, drafting comprehensive derivative regulations and implementing a detailed carbon trading roadmap for various sectors remains a challenge.  

7. Issues of Additionality and Double Counting: Offset projects must be able to prove that the emission reductions generated are "additional" (would not have occurred without the incentive from the carbon market). Furthermore, the risk of double counting reduced emissions, both nationally and internationally, must be effectively mitigated.  

4. Carbon Tax vs. Carbon Credits: A Comparative Analysis for Indonesia

After dissecting the basic concepts, mechanisms, and potential advantages and disadvantages of carbon tax and carbon credits (carbon trading) separately, it is important to conduct a comparative analysis to understand their fundamental differences and how Indonesia plans to use them in the context of national climate policy.

Fundamental Differences

The most fundamental difference between a carbon tax and a carbon trading system (specifically an Emission Trading System - ETS or cap-and-trade) lies in the primary instrument used to influence emitter behavior:

• Carbon Tax: Is a price instrument. The government directly sets the price (tax rate) per unit of carbon emissions. This provides certainty regarding the cost of emissions for economic actors. However, the total amount of emission reduction achieved becomes less certain, as it depends on the markets response to the set price.  

• Carbon Credits (ETS/Cap-and-Trade): Is a quantity instrument. The government sets an upper limit (cap) on total permissible emissions for a specific period. This provides certainty regarding the total amount of emission reduction that will be achieved (in aggregate, emissions will not exceed the cap). However, the price of carbon credits will be formed through market mechanisms (supply and demand) and can fluctuate.  

How Indonesia Plans to Use Both Instruments

Looking at the regulatory framework and implementation steps already taken, Indonesia does not seem to be choosing one instrument exclusively but is adopting a hybrid or complementary approach. This reflects pragmatism in facing the complexity of emission reduction, where each instrument has its own strengths and weaknesses. A hybrid approach has the potential to leverage the strengths of both mechanisms while attempting to mitigate their weaknesses.

Some indications of this hybrid approach include:

1. "Cap and Tax" Scheme: As stipulated in the HPP Law, the "cap and tax" mechanism explicitly combines emission limit elements (cap) with the option for companies to pay a carbon tax (tax) on excess emissions, or purchase emission permits/credits to meet their obligations. This directly links the two instruments.  

2. Launch of IDXCarbon Preceding Full Carbon Tax Implementation: The carbon exchange (IDXCarbon) was launched and has been operational since September 2023 , while the full implementation of the carbon tax is targeted for 2025 after several postponements. This implementation sequence could be a deliberate strategy. With the carbon market operating first, the government and market players can gain experience, observe price formation dynamics, and identify practical challenges. This also provides an opportunity for industries to start familiarizing themselves with the concept of carbon pricing and provides an alternative compliance mechanism before a more coercive tax is widely implemented. On the other hand, this sequence could also be a consequence of the greater and more complex challenges in preparing for the national implementation of the carbon tax.  

3. Carbon Tax as a Potential Price Floor or Penalty: In a hybrid system, a carbon tax can function as a price floor in the carbon market, preventing credit prices from falling too low. Additionally, a carbon tax can also serve as a penalty for entities that do not meet their obligations under a cap-and-trade scheme, or be imposed on sectors that are difficult to reach or not covered by carbon trading mechanisms.

4. Inclusive NEK Framework: Presidential Regulation No. 98 of 2021 concerning the Implementation of Carbon Economic Value clearly mentions both instruments—levies on carbon (which form the basis of carbon tax) and carbon trading—as integral parts of the national NEK strategy.  

The success of this hybrid approach will heavily depend on the careful design of the interaction between these two instruments. How the emission "cap" level is set, how the carbon tax rate interacts with the price formed in the carbon credit market, and how the sectoral coverage for each instrument is determined will be crucial factors. This approach, while offering flexibility, also adds complexity in terms of regulation, implementation, and supervision.

Table 2: Summary Comparison of Carbon Tax and Carbon Credits in Indonesia

5. Assessing Effectiveness for Indonesia: Challenges and Opportunities

The effectiveness of implementing carbon tax and carbon trading in Indonesia depends not only on the theoretical design of each instrument but also on how implementation challenges unique to the national context can be overcome and how potential synergies between them can be maximized. The key to success lies in the ability to build a supportive policy ecosystem, not just choosing one instrument over the other.

Analysis of Implementation Challenges for Each Instrument in Indonesia

• Carbon Tax:
  
  

• Setting an Effective and Fair Tariff: The main challenge is to determine a carbon tax rate that is high enough to drive behavioral change and significant emission reductions, but not so burdensome as to negatively impact the economy or cause undesirable social impacts. The initially planned rate of IDR 30,000 per ton of CO2​e may require periodic evaluation and adjustment to remain relevant to climate targets and market conditions.  

• Tax Administration and MRV System Readiness: Carbon tax implementation requires a tax administration system capable of handling this new mechanism, as well as a reliable Measurement, Reporting, and Verification (MRV) system to accurately measure emissions as the basis for taxation. The cost of building and operating a credible MRV system can be significant. The quality of this MRV system is a shared critical point, as both carbon tax and carbon trading heavily depend on it to ensure accountability and effectiveness.  

• Industry and Public Acceptance: Carbon tax policy may face resistance from carbon-intensive industries due to increased operational costs. Additionally, potential impacts on inflation and the competitiveness of national products also need to be carefully managed. Effective public communication and fair compensation or transition mechanisms for affected groups are important.  

• Inter-Agency Coordination: Carbon tax implementation requires close coordination among various government agencies, including the Ministry of Finance, the Ministry of Environment and Forestry, relevant sectoral technical ministries, and local governments.
  
  

• Carbon Credits (Carbon Trading):
  
  

• Creating a Liquid and Efficient Market: One of the biggest challenges for IDXCarbon is to build a sufficiently liquid market with significant trading volume so that the formed carbon price truly reflects the marginal cost of emission reduction. The initial price trend downwards after launch suggests that demand may not yet be as strong as supply, or other factors are influencing early market dynamics.  

• Ensuring Carbon Credit Integrity: The credibility of the carbon market heavily depends on the quality of traded credits, especially SPE-GRK from offset projects. Issues such as additionality (ensuring that emission reductions would not have occurred without carbon market incentives), permanence (especially for forestry projects), and prevention of double counting must be addressed with a strict MRV system and verification by independent and competent third parties.  

• Market Participant Capacity: Market participants, both sellers and buyers of carbon credits, require adequate understanding and capacity to participate effectively in the carbon exchange. This includes the ability to develop carbon projects that meet standards, conduct MRV, and understand trading mechanisms.

• Effective Supervision: Strong supervision from OJK over the exchange operation and transactions, as well as from MoEF over carbon unit standards and registration (through the National Registry System for Climate Change Control - SRN PPI), is crucial to maintain market integrity.  

• Developing a Clear Roadmap: Effective implementation of carbon trading requires a clear and detailed roadmap for each sector involved, including the setting of emission caps and their allocation.  

Potential Synergies: Is a Hybrid Model Most Suitable for Indonesia?

Given the complexity of Indonesias economic structure, its reliance on land-based and natural resource sectors, and its ambitious NDC targets, a hybrid approach combining elements of carbon tax and carbon trading seems to offer the greatest potential. Synergies between these two instruments can be optimized:

• A carbon tax can function as a price floor in the carbon market, providing minimal certainty for green project investors and preventing credit prices from falling too low. Conversely, the price formed in the carbon market can serve as a reference for adjusting carbon tax rates.

• A carbon tax can be applied to sectors or emission sources that are difficult to reach or less efficient if included in a cap-and-trade system, such as emissions from the diffuse transport sector or small-scale enterprises.

• Revenue generated from a carbon tax can be allocated to support carbon market development, for example, by funding the development of high-quality SPE-GRK generating projects, or to address the social impacts of carbon pricing through social assistance programs or retraining for workers in affected sectors. A report from the World Bank also recommends that Indonesia implement fiscal policies that include carbon pricing and energy subsidy reform as part of its transition strategy towards a low-carbon economy.  

Projected Impact on NDC Achievement and the National Economy

The implementation of carbon pricing instruments, both tax and trading, is expected to make a significant contribution to achieving Indonesias NDC target of 29-41% by 2030. By assigning economic value to carbon emissions, both instruments encourage companies and individuals to find more efficient ways to use energy and reduce their carbon footprint.  

Economically, the impact can be twofold. On one hand, there will be increased costs for high-emitting industries, potentially affecting short-term competitiveness if not managed well. However, on the other hand, carbon pricing policies can also trigger innovation in green technology, create new markets for low-carbon products and services, and attract investment in renewable energy and energy efficiency sectors. Potential state revenue from carbon taxes or the sale of emission permits can also be used to support sustainable development.  

However, it is important to emphasize that the transition to a low-carbon economy must be a just transition. The government needs to design accompanying policies to minimize negative impacts on vulnerable communities and workers in sectors that may experience disruption, for example, through social safety net programs, new skills training, or support for economic diversification in regions dependent on fossil fuel industries. The balance between environmental ambition and socio-economic-political realities is key. Carbon pricing policies that are too weak may not effectively achieve climate targets, while policies that are too strict too suddenly can cause economic turmoil and political resistance. Therefore, a gradual, adaptive approach, supported by constructive dialogue with all stakeholders, seems to be the most prudent path.

6. Conclusion: A More Effective Direction for Indonesias Carbon Policy

The debate over whether a carbon tax or carbon credits (carbon trading) is more effective for Indonesia does not have a simple, single answer. Both instruments have their respective advantages and disadvantages, and face specific implementation challenges in the Indonesian context as a developing archipelagic nation with a diverse economic structure and reliance on land-based and commodity sectors.

A carbon tax offers price certainty and potential stable state revenue, but setting the right tariff and managing its socio-economic impacts are crucial. On the other hand, carbon trading (through cap-and-trade and offset mechanisms) offers flexibility and cost efficiency in achieving emission targets, but requires a liquid market, high-quality credits, and strict oversight to avoid excessive price volatility and integrity risks.

Indonesia, through its Carbon Economic Value (NEK) framework and various derivative regulations, appears to be moving towards a hybrid model that integrates elements from both approaches. The "cap and tax" scheme and the launch of the Indonesia Carbon Exchange (IDXCarbon) preceding the full implementation of the carbon tax are manifestations of this strategy. This approach theoretically can leverage the strengths of each instrument while mitigating their weaknesses.

The effectiveness of carbon pricing policy in Indonesia will ultimately be determined not only by the choice between tax or trading, but by the quality of the design and implementation of the entire supporting policy ecosystem. Several key elements will determine long-term success:

1. Strengthening the MRV System as the Main Foundation: A credible, transparent, and accountable Measurement, Reporting, and Verification (MRV) system is an absolute prerequisite for both instruments. Without the ability to accurately measure, report, and verify emissions and emission reductions, neither carbon tax nor carbon trading will be effective and will lose credibility.

2. Setting Ambitious yet Realistic Emission Targets ("Cap"): For a cap-and-trade carbon trading scheme, setting an emission cap that gradually declines and aligns with NDC targets is essential to drive demand for carbon credits and real emission reductions.

3. Periodic Evaluation and Adjustment of Carbon Tax Tariffs: If a carbon tax is implemented, its tariff needs to be periodically evaluated and adjusted to remain relevant in driving decarbonization, considering inflation, technological developments, and carbon prices in regional/global markets.

4. Enhancing Inter-Agency Coordination: The implementation of this complex carbon policy requires strong synergy and coordination among the Ministry of Finance, the Ministry of Environment and Forestry, the Financial Services Authority, sectoral ministries, and local governments.

5. Increasing Stakeholder Capacity and Awareness: Continuous efforts are needed to improve the understanding and technical capacity of industry players, financial institutions, verifiers, and the general public regarding carbon pricing mechanisms and related opportunities.

6. Transparency in Carbon Revenue Management: If carbon pricing policies generate revenue for the state, the management and allocation of these funds must be done transparently and accountably, ideally directed towards supporting a just green transition, investment in renewable energy, and other climate adaptation-mitigation programs.

7. Long-Term Policy Consistency and Certainty: To encourage long-term investment in low-carbon technologies, the government needs to provide consistent policy signals and regulatory certainty.

Indonesia is in the early stages of its journey in implementing carbon pricing policies. A "learning by doing" approach and mechanisms for periodic policy evaluation and adaptation will be crucial. The ability to monitor impacts, identify challenges, and make adjustments based on data and field experience will be the main determinant of whether the chosen carbon pricing instruments can effectively help Indonesia achieve its climate targets while supporting a sustainable and equitable national development agenda.