Carbon removal
Carbon removal refers to the process of actively removing carbon dioxide (CO₂) from the atmosphere and storing it in a stable form. This can be achieved through a variety of methods, including reforestation, afforestation, soil carbon sequestration, and direct air capture. Carbon removal is considered a critical component of climate change mitigation strategies, as it can help reduce atmospheric CO₂ concentrations and offset ongoing emissions from human activities.
There are several important considerations when evaluating carbon removal projects and technologies. Firstly, it is important to ensure that the carbon is removed from the atmosphere and stored in a stable form that minimizes the risk of re-emission. This is known as "permanence." Secondly, it is important to consider the scale and speed of the carbon removal process. Some methods, such as afforestation and reforestation, can take decades to sequester significant amounts of carbon, while others, such as direct air capture, can remove large quantities of CO₂ in a relatively short period of time.
The Oxford Net-Zero Offsetting Principles provide a useful framework for evaluating the effectiveness of different carbon removal methods. According to these principles, there are five categories of carbon offsets, ranging from "avoided emissions" (Category I) to "carbon removal with long-lived storage" (Category V). Category V offsets are considered the most effective, as they involve physically removing CO₂ from the atmosphere and storing it in a stable form for a long period of time.
It is important to note that not all carbon offset projects are created equal. Some projects, such as "compensation" projects that aim to offset emissions without reducing them, are considered less effective at addressing climate change. Instead, it is recommended to focus on "removal" projects that actively remove CO₂ from the atmosphere and store it in a stable form.
References:
Oxford Net-Zero Offsetting Principles. (2022). https://www.oxfordnetzero.ox.ac.uk/offsetting-principles/
IPCC. (2018). Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. Geneva, Switzerland: IPCC. https://www.ipcc.ch/sr15/
