The Path to Net Zero
Why Net Zero? - Climate science has made it clear that the simple reduction of carbon emissions is no longer enough to stop climate change. Emissions need to fall to zero quickly to meet the targets of the Paris Agreement and it is clear that, without drastic change, this is not going to happen quickly. So long as the net emission of carbon remains above zero, carbon emission will continue to accumulate in the atmosphere. This is where Net Zero comes in as a solution to speed up the fall of emissions in the atmosphere. Net Zero is about removing as much carbon dioxide from the atmosphere as is produced.
In many industries, substantial greenhouse gas reductions can already be achieved with the technologies available today – for example by using renewable energies or switching to green power generation. Other industries, however, such as aviation and agriculture, are more limited in their opportunities to bring their emissions down to a true zero.
Net Zero is for the industries where, even after decarbonization measures are in place, there are emissions remaining. The equivalent of these remaining emissions must then be removed from the atmosphere, so as to bring the overall balance back down to zero. Net Zero can account for carbon dioxide specifically, or for all greenhouse gases, which would be measured as carbon dioxide equivalent, or CO2e.
Removing Carbon from the Atmosphere
Carbon dioxide is the only greenhouse gas that is easily removed from the atmosphere and there are two main ways of doing this: biogenic removal or technological removal. Certain technologies, such as direct air capture and storage, remove the carbon from the atmosphere and store it in a geologic reservoir. The biogenic form of carbon removal is done predominantly through plants, which absorb carbon during photosynthesis. This is then stored in biomass and is known as a natural carbon sink. By increasing vegetation stocks through initiatives such as afforestation or reforestation, the carbon sinks grow to absorb and retain more carbon dioxide from the atmosphere.
It should be noted that carbon capture and storage, in which carbon is captured from fossil fuel emissions, does not contribute towards carbon removals since it merely avoids the emission of carbon dioxide and does not remove any carbon that is already in the atmosphere.
Whether it’s technological or biogenic, the removal of carbon dioxide from the atmosphere will make a significant step in the direction of becoming net-zero. In the long run, with the development of new technologies, all economic sectors could become emissions-free and the world could become carbon negative, meaning it would absorb more carbon than it produces.
The Role of Carbon Offsetting in Reaching Net Zero
Whilst decarbonization and carbon removals are the priority for reaching Net Zero, it will still take a while to reach a net zero state. Those industries that are limited in existing and feasible technology to rapidly decarbonize are expected to set their net-zero goals for a later date than those which already have the means to significantly reduce their emissions. During the decarbonization process, whether long or short, it is important to continue to push global emissions down. Alongside the physical removal of carbon through biogenic and technical removals, carbon offsets can also be used.
Carbon offsets complement carbon removals and decarbonization in the transition to a net-zero state. Even after a net zero state has been reached, carbon offsets can still be an asset to a sustainability strategy. This is because most offset projects also generate co-benefits, which go beyond simply reducing carbon emissions.
These can include improved health, increased availability of renewable energy, or provision of new employment opportunities and are often measured using the United Nations 17 Sustainable Development Goals.
Beyond this, continuing to invest in carbon offsets even after reaching a net-zero state allows companies or associations to reach a net-negative state, in which they remove more emissions than they produce. This then has a positive impact on the global climate and is commonly known as ‘carbon positive’.
Setting a Net Zero Target
Net zero targets can be set on various levels, from corporate level to state-wide. Setting a net zero target highlights commitment to halting climate change and can contribute to social and economical development.
Whilst targets are often focused on carbon dioxide, it is possible to set targets that cover all greenhouse gas emissions recognized by the UNFCCC. For state-wide targets, some of the carbon reductions needed to meet the target will come in the form of carbon removals, particularly if the state includes emissions from their aviation and shipping industries, which currently lack the technology for affordable and efficient mitigation.
To be able to cut emissions in line with a 1.5°C scenario as set out by the IPCC, drastic changes need to be made. Renewable energy is already well developed, and its increasing integration into power grids across the globe will make significant reductions to carbon emissions. Fuel switching and efficiency measures in the transport sector are also major keys to cutting a country’s carbon footprint.
Technologies such as low carbon hydrogen could help reduce emissions from the heating sector and can stabilize renewable energy sources so that they can be better integrated into national grids. Even with these measures in place, carbon removals and carbon offsets will most likely still be required to achieve Net Zero within the required time frame.
The Science Based Targets initiative (SBTi) recently released their first-ever guidelines to help corporates understand and set net zero targets. According to SBTi, more than half of the global economy is now covered by net-zero commitments. Despite this, however, a lack of existing guidance has meant that corporate approaches to Net Zero have been largely inconsistent. As a result, the paper was written to increase consistency by providing clarity around net-zero and setting net-zero targets. The paper analyzes various strategies for setting net-zero targets and then puts forward its own recommendations, which focus on abating emissions in line with science to create a climate-positive approach going beyond Net Zero. They also recognize the importance of carbon offsetting in the transition phases to Net Zero and beyond.