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Thursday 22nd April 2021

We’ve all heard the term net zero. It follows from the ground-breaking IPCC 2018 report, which warned that if we do not reach net zero by 2050, global warming will surpass 1.5 degrees – with catastrophic effects on our planet and people.  

But what exactly is net zero?  


Interestingly, there is still no universal definition of net zero. The IPCC defines it as: 

‘Net Zero is reached when anthropogenic (human-caused) emissions of greenhouse gases to the atmosphere are balanced by anthropogenic removals over a specified period’. 
 

Net zero refers to the balance between the amount of greenhouse gas produced and the amount removed from the atmosphere. There are two routes to achieve net zero which work in tandem – reducing existing emissions and actively removing them.  

It can be described like a bath with a running tap – to achieve an overall balance you could turn down the taps (reduce emissions) or drain an equal amount (removing emissions from the atmosphere).  

Net zero, net zero carbon, offsetting, carbon reduction... confused?

Often used interchangeably there are several key terms relating to net zero and climate action. As more nations, organisations and individuals start their climate action journey, there are more and more terms describing their commitments. It therefore worthwhile to understand some of the key differences:  

Net zero carbon 


Net zero carbon measures carbon emissions only. In comparison, ‘net zero’ as defined by the Greenhouse Gas Protocol (GHGP) measures all greenhouse gases, including carbon dioxide, methane (which has a Global Warming Potential 80 times that of CO2) and nitrous oxide and some others.  

Carbon neutral  


Carbon neutral targets carbon emissions only and has a different ‘accounting standard’ to the Greenhouse Gas Protocol (GHGP). For example, it can relate to just part of an organisation’s activities. It is reported that 90% of businesses now use the GHGP methodology. 

Gross-zero target  


A gross zero target would mean reducing emissions from all sources, uniformly to zero. A net zero emissions target is far more realistic because it allows for some residual emissions. There are several industries such as aviation and manufacturing where it is too expensive, complex or simply impossible to cut all emissions. And that’s where credible offsetting plays a part.  

Carbon offsetting 


Carbon offsetting is where the same amount of carbon produced is avoided somewhere else (I.e., carbon offset credits are bought). At its core, an offset is an accounting mechanism. It’s a way of trying to balance the scales. 

Carbon removal 


Carbon removal is where the same amount of carbon produced is removed (rather than avoided) from the atmosphere. This is often done by planting trees as they store carbon and release oxygen. This is the preferred choice, as emissions are directly removed. To be credible a carbon reduction scheme needs to be certified to ISO 14064:2. 

Science Based Targets 


The Greenhouse Gas Protocol is the ‘accounting standard’ for emissions and the Science Based Target Initiative (SBTi) takes this further, by setting targets and dates for implementation. A SBTi is informed by climate science and is widely considered to be a preferred and credible approach to setting targets. 


Overall, these terms all share the same underlying goal – to substantially counteract the emissions produced by a product, business or country for the climate. It’s important to understand your own goals, short to long term and decide which route to solving the climate crisis best suits you and your business needs. The most important thing is transparency – being clear about what you are actually doing, measuring and reporting.

Jessica Parrilla

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