Introduction to CDR
The global average temperature of the planet is strongly affected by the amount of greenhouse gases, particularly carbon dioxide, we’ve emitted into the atmosphere over the last century or so. Most of this carbon dioxide is from combustion of fossil fuels. Even if humans nearly eliminate emissions from fossil fuel combustion in the next few years, we’ve already put so much carbon dioxide into the atmosphere that we would exceed many countries’ (including Canada’s) goal of keeping global average temperatures from rising more than 1.5°C above pre-industrial levels.
Carbon dioxide removal (CDR) is an important tool that can help turn back the carbon clock by removing some of the legacy emissions that humans have released into the atmosphere over the last century.
Carbon dioxide removal can also address greenhouse gas emissions that cannot be eliminated due to the high cost or lack of available technology to do so, as well as natural source emissions that might increase over time, like melting permafrost. By counterbalancing these emissions, CDR can clear that last hurdle towards net-zero.
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In 2025, Canada updated its climate plan under the Paris Agreement. The goal is to cut greenhouse gas emissions by 40 to 45 per cent below 2005 levels by 2030 and achieve net-zero emissions as a nation by 2050. This aims to limit global temperature rise to less than 1.5°C compared to pre-industrial levels.
There are several low-cost ways to reduce emissions using existing technologies. These include switching from fossil fuels to electricity for transportation and heating, using more renewable energy and improving the energy efficiency of buildings. Reducing emissions from fossil fuel production and capturing and storing carbon dioxide (CO2) from fossil fuel use are also critical solutions to limit global warming.
However, even with these measures, some emissions will remain. These are called hard-to-abate emissions because they are difficult or costly to eliminate. In fact, there might not be any viable options to avoid those emissions before 2050. For example, industries like aviation are hard to decarbonize because alternatives to jet fuel are often expensive and challenging to produce sustainably in large quantities.
For these emissions, the only solution is to remove them from the atmosphere after they are released. In its 2022 climate report, the Intergovernmental Panel on Climate Change said carbon dioxide removal is unavoidable and necessary to deal with these leftover emissions and reach net-zero targets.
Reducing emissions stops more CO2 from entering the atmosphere, but it doesn't remove the CO2 already there. These emissions stay in the atmosphere and impact the climate for hundreds of years. Climate change is driven by the cumulative emissions of CO2 over time – i.e., by adding up all the CO2 emissions year after year. CDR is a set of tools that can address these emissions that are already in the atmosphere.
From a cost perspective, CDR is not the optimal way to address all emissions. Durable CDR, which refers to CDR methods that can store CO2 for thousands of years, costs around $300-800 per tonne of CO2 removed (/tCO2), according to some estimates. By comparison, for example, recent analysis suggests that many opportunities for emissions reductions through methane management in fossil fuel operations cost less than $25 per equivalent tonne of CO2.
Last Edited - Sept. 20, 2025