Carbon pricing instruments can take on multiple forms. Ultimately, all approaches aim to create a price signal on GHG emissions. The manner in which this is achieved differs across instruments.

碳定价工具可以采取多种形式。最终，所有方法都旨在指导温室气体排放的价格。实现这一目标的方式因不同机制而异。

An Emission Trading System (ETS) – also known as cap and trade – is a tradable-permit system for GHG emissions. It sets a limit (the cap) on the GHG emissions that can be emitted. Entities covered by the ETS need to hold one emission unit (allowance) for each tonne of GHG emitted, but entities have the flexibility of selling and buying emission units. The total number of emission units reflects the size of the cap in the ETS. Under this approach, the price on carbon will depend on the balance between demand (the total emissions) and the supply (the emission units allocated and available).

排放交易系统(ETS) – 也称为限额与交易 – 是温室气体排放的可交易许可证系统。它对可排放的温室气体排放量设定了限制（上限）。ETS覆盖的实体每排放一吨温室气体需要持有一个排放单位（配额），但实体可以灵活地出售和购买排放单位。排放单位总数反映了碳排放交易体系中上限的大小。在这种方法下，碳价格将取决于需求（总排放量）和供给（分配和可用的排放单位）之间的平衡。

Emission Reduction Funds are taxpayer funded schemes in which a government buys credits created by emission reduction projects. Currently, an Emission Reduction Fund is operational in Australia.

减排基金是纳税人资助的计划，政府购买减排项目产生的信用。目前，减排基金正在澳大利亚运作。

A Carbon Tax on fossil fuel usage creates a price signal felt across an entire economy, thereby incentivizing a move away from carbon-intensive production. This results in a total reduction of emissions. Unlike an ETS, a carbon tax cannot guarantee a minimum level of GHG reductions, but instead ensures certainty around the size of the price signal on carbon.

对化石燃料使用征收碳税会在整个经济体中产生价格信号，从而激励人们放弃碳密集型生产。这导致排放总量减少。与碳排放交易体系不同，碳税不能保证最低水平的温室气体减排，而是确保碳价格信号大小的确定性。

Depending on the particular needs of the jurisdiction contemplating carbon pricing, a Hybrid Approach can also be considered, combining elements of an ETS and carbon tax. For example, a jurisdiction might set up an ETS with either a maximum or minimum price per allowance, or set up a carbon tax scheme that accepts emission reduction units to lower tax liability.

根据考虑碳定价的司法管辖区的特定需求，还可以考虑采用混合方法，将碳排放交易体系和碳税的要素结合起来。例如，某个司法管辖区可能会建立一个碳排放交易体系，规定每项配额的最高或最低价格，或者建立一个碳税计划，接受减排单位以降低纳税义务。