的 science is irrefutable – it is necessary to drastically and urgently reduce greenhouse gas emissions to limit global warming to 1.5°C.[1] 然而, it is also becoming increasingly clear that reducing emissions will not be enough: removing significant quantities of carbon dioxide from the atmosphere will also be key.
有一系列基于自然和技术的解决方案可以从大气中去除碳. 这些主要是, 虽然不完全如此, 通过碳市场的信用计划融资. 最近的媒体报道集中在围绕自然和技术解决方案的辩论上。 相对重要性 以及更广泛的碳信用额度的话题. Common criticisms focus on the credibility of corporate claims from the use of carbon credits as well as the quality of the crediting accounting frameworks. 虽然这些都是需要解决的重要问题, 对碳清除的投资, 通过购买积分或其他方式, 是否仍是尽快实现“全球”净零排放的关键.
This article highlights the vital role that carbon removals can play in corporate climate strategies and calls on businesses to consider developing a portfolio of climate mitigation solutions beyond the value chain, 包括各种基于自然和技术的去除解决方案.
碳清除在企业气候战略中的作用
对于一家公司来说，最迟在2050年实现净零碳排放, 它需要减少自身运营中的排放，并积极支持其供应商和客户的脱碳. 根据科学目标倡议(SBTi) 企业净零标准, 那些希望建立与全球变暖情景1相一致的近期和长期目标的公司.5°C必须在2050年或更早之前将价值链排放减少到不超过净零基线10%的剩余水平.
大多数公司不允许使用碳去除量来声称在实现中期脱碳目标方面取得了进展, 除了森林里的那些, 土地使用和农业部门在该公司的供应链中发生搬迁. 这是为了确保减排活动得到优先考虑. Carbon removals instead feature in two other key elements of a company’s net-zero journey – neutralizing residual emissions at net zero and in “beyond value chain mitigation.”
Companies must neutralize their residual emissions at and beyond 净零点 by purchasing an equivalent quantity of permanent removals. 这些投资可以通过购买清除积分或通过价值链内的清除活动. 这些移除的永久性目前有不同的解释, 尽管定义永恒的工作仍在进行中. 实现化石燃料净零排放中和的运动正在不断发展 持久的、技术性的清除 实现永久的气候稳定，避免对土地使用造成不适当的压力. 这绝不能破坏自然气候解决方案(NCS)达到或超过净零的持续价值. 的re will still be a significant role for the neutralization of residual emissions from the land use sector and to generate additional environmental and social benefits.
企业还应投资于碳清除，作为SBTi所称的“超越价值链缓解”的一部分。. 这是指企业自愿参与其价值链之外的气候减缓活动, 比如购买碳信用额, 在实现净零排放的过程中平衡不减的排放. 最近的“诚信问题” report from the UN High-Level Expert Group (HLEG) emphasized the importance of this activity to help drive broader global climate action and help companies make carbon neutrality claims on the path to net zero. 这些投资可以与减少碳排放或消除碳的项目相关联. 公司需要考虑开发同时考虑这两种解决方案的投资组合. 目前关于相对比例的正式指导有限, though SBTi currently recommends prioritizing projects that restore and enhance natural carbon sinks to protect remaining intact ecosystems in the near term. 然而，公司应该同时开始投资于技术去除解决方案. 这些解决方案仍处于相对初级阶段，而且 投资快速增长 is needed to overcome the significant techno-economic challenges preventing these solutions from being deployed at scale to help achieve global net zero emissions.
一些公司可能希望投资于足够的清除，以实现净负, 或者“气候积极”, at, 或之后, 净零点. 的 政府间气候变化专门委员会(IPCC) identified that carbon negativity will be key to mitigating an expected overshoot in the global carbon budget associated with keeping average global warming to 1.5°C. 少数领先的公司已经设定了碳负目标, meaning they will remove from the atmosphere all the carbon they have emitted either directly or indirectly since their creation. 目前还没有标准的方法来验证这一点，也没有标准的方法来决定可以使用哪种除碳溶液. 基于科学的碳核算方法和碳负索赔实践的标准化可以确保这一点, 同时创造新的需求信号，刺激私营部门投资.
Figure 1:企业零净路径的一个例子
有哪些解决方案?它们有何不同?
在不同的发展阶段，有许多不同形式的碳去除解决方案. 基于自然的清除包括植树造林和土壤碳固存. 技术解决方案的例子包括生物炭, 具有碳去除和储存(BECCS)和直接空气捕获的生物质, 碳储存(DACCS). 适用于所有解决方案的属性范围各不相同. 其中包括成本, 技术准备和气候影响, 比如持久性和反照率的变化(一种衡量地球表面反射程度的指标).
它们也有不同的非气候影响, 比如资源竞争, 生物多样性的影响, 支持当地社区和土著人民. 这些通常对NCS是积极的，因此通常被标记为核心利益. 然而，这些可能对某些，特别是技术解决方案是负面的. 例如, 为了让他们运作, direct air capture facilities consume significant quantities of renewable energy to operate that could theoretically be used elsewhere for direct electrification. 这种位移效应必须考虑在内.
在不同的清除方案之间做出投资决策, 理解它们各自的属性是至关重要的, 结果和特定的投资需要证明不同的价格点是合理的. 的 most critical element that defines a solution’s climate impact over time is its storage durability – a measure of permanence and the risk of reversibility (re-emission). 关于清除的常见争论集中在基于自然的清除和技术清除之间的基本持久性差异上.
然而, 尽管根据耐用性的差异来合理定价是关键, 符合永久去除碳的目标, this must not disincentivize investment into less durable removal types that are still paramount to short-term climate mitigation. 这将赢得必要的时间, 或者“碳预算”, 随着社会的脱碳，更持久的解决方案被扩大. It also shouldn’t undermine the value of the wide variety of environmental and social co-benefits that some removal solutions can provide. 除了除碳之外，每个除碳解决方案都提供了一套独特的好处.
多元化碳清除组合的重要性
Deciding on which carbon removals to invest in can be daunting - there are many methods with a plethora of different characteristics. 而不是投资于单一或有限的解决方案, a portfolio approach to investing in a diverse range of both nature-based and technological removals will allow for synergies and counteract the tradeoffs between the different solutions.
这种方法的主要好处包括:
- Initial prioritization of more readily available NCS will help to restore natural ecosystems while also starting to remove carbon from the atmosphere at scale.
- Portfolios that also include gradually increased investment in technological removals will help to drive the innovation needed for them to be deployed at the scale necessary to reach net zero emissions by 2050.
- 的 various co-benefits across the different solutions can be maximized to help companies achieve progress against broader corporate sustainability targets.
- Solutions that emerge as the most effective and that meet the requirements of future compliance markets will be sufficiently well-developed to be more commercially viable.
- 不同解决方案的潜在风险或负面影响可以分散到整个投资组合中.
WBCSD helps companies navigate this confusing and fast-moving space by developing removals investment guidance which includes a science-based framework to objectively compare different forms of removals across both nature and technology.
作为下一步, WBCSD will develop high-level guidance on developing a beyond-value chain mitigation portfolio which will provide blueprints on the relative contributions of different carbon reduction and removal solutions. This will help companies create ambitious and diverse portfolios that will drive broader climate action to achieve global net zero emissions.
如有兴趣查询更多资料，请联络: gray-wannell@somechan.net
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[1] Carbon dioxide removal projects are activities initiated by humans that result in a net removal of CO2 from the atmosphere, 将二氧化碳持久地储存在水槽中. 这种二氧化碳储存通常要经过一段时间的监测和核查，以确保二氧化碳没有重新排放. 这些汇可以是生物源的、海洋的或地圈的. 移除解决方案的两个定义特征是移除机制(例如.g.(陆基生物、地球化学或化学)和储存介质(如.g.(生物质、产品或地质).
