Carbon Jargon Buster

Posted in: Student blog

Ever get lost in carbon jargon? Read our placement student Vasudef's blog, where he simplifies carbon terminology. You may discover a new term!

Have you come across phrases that many companies are using nowadays about their environmental impact, such as “we've pledged to be net zero by 2050”? You might have a good idea of what it means, or you might not have a clue. This blog post can equip you with the necessary knowledge to figure out which companies and institutions are genuine about their climate policies, and those who might be sharing greenwash.

Greenhouse Gases

Greenhouse gases surround the Earth and keep it warm. If there were none in the atmosphere, then it would be too cold for us to live, with an average temperature of -20°C! However, since the industrial revolution, we have released a lot more greenhouse gases in addition to the ones already in the atmosphere – we released the equivalent of 53.85 billion tonnes of carbon dioxide (CO2 ) in 2022. This includes carbon dioxide, water vapour, methane and nitrous oxide (amongst others). Carbon dioxide is the most common gas emitted as a result of human activity, so when people say 'carbon', it usually means greenhouse gases collectively. 

Carbon Footprint

A carbon footprint refers to someone’s (or something’s) total greenhouse gas emissions in a given time period (usually a year). We each have a carbon footprint and by understanding it, we can reduce our personal impact on climate change. If you’re interested to find out yours, I’d recommend this footprint calculator, which is a super easy and quick tool to use.

It’s important for organisations to calculate their carbon footprint too. Here I’ve shared a breakdown of the University’s 2022-23 footprint:

If you would like more information on the breakdown, I highly recommend looking at the Climate Action Annual Report, where you can read into the nitty-gritty of the footprint (and also find out why the emissions increased from last year). As shown above, the bar graphs show that the University emitted about 130 ktCO2e last year, while the pie chart shows the breakdown of the footprint. The e in the “ktCO2e” stands for equivalent, which means that a mixture of greenhouse gases have been released to the atmosphere, but the impact it has on the earth is equivalent to this amount of carbon dioxide.

Scopes 1, 2 and 3 Emissions

When you hear about carbon footprints, you might also hear mention of scope 1, 2 and 3 emissions. The three different scopes refer to different types of emissions.

Scopes 1 and 2 refer to emissions that are produced from fuel sources. Gas and electricity fall within these 2 scopes. The difference between them is that Scope 1 comes from direct University activities (any fuels we consume on site), and Scope 2 is any energy that we purchase and receive from outside the University. 

And Scope 3 is…. everything else. For the University, it can include a range of things, including, for example, students taking the bus to campus, purchasing lab equipment and staff travel overseas for conferences. The list can be very exhausting. Looking at the bar charts above, notice how the gas, fuels and electricity in red and orange (Scopes 1 and 2) make up only a small fraction of the graph, while the supply chain and travel (Scope 3) make up the majority of emissions. 

It is important that the University has set these targets to ensure that the University is doing its part to tackle climate change. Most UK universities have set targets to reduce these remaining emissions by certain years. The University’s net zero targets are as follows: 

  1. Net Zero in Scopes 1 and 2 by 2030, and halve our Scope 3 emissions in that time. 
  2. Net Zero in all scopes by 2040 

Net Zero

You might have heard this term a lot, or even seen the big sign in front of the SU declaring the University’s commitment to reach net zero, but what does this actually mean? 

An institution that has declared to be ‘net zero’ has committed to ensure that the emissions they release are equal to the emissions that they remove from the atmosphere. The idea is that the net amount of emissions released into the atmosphere would be zero. There are many different ways that organisations can achieve this goal and it can be a bit contentious, as well as being open to greenwash. Below are some key things to look for that can indicate if an organisation is genuine about being net zero: 

  • Net Zero commitments should cover all three emission scopes 
  • Organisations should first reduce their emissions as much as possible (this should be the priority!) 
  • They then need to be transparent on how they will address the emissions that cannot be reduced 

When it comes to reaching net zero and addressing those remaining emissions, organisations may consider a variety of approaches such as carbon offsetting or insetting. For example, if a company has managed to reduce its emissions to 10 ktCO2e per year, and cannot feasibly reduce it further, it can invest in an offset to remove 10 ktCO2e , therefore making them net zero. 

Carbon Offsetting/Insetting

Carbon offsetting refers to the act of purchasing carbon credits from an external provider, who will then invest in projects that actively remove carbon from the atmosphere, such as ecosystem restoration or carbon capture and storage technology. 

Carbon insetting is when an organisation uses their own resources, or performs a carbon reduction activity within their own land or supply chain, i.e. growing forests on their own land. 

However, organisations cannot solely invest in offsets/insets, as this may result in the company not focusing on reducing its emissions first. 

There are a variety of offsetting projects currently available, with varying factors that can impact the effectiveness of the project, with a few listed below: 

  • Is the project genuinely reducing emissions? 
  • Will the project remove the emissions right now, or will it happen in the future? 
  • Are there any additional benefits? (Social, biodiversity, etc.) 
  • Is there confidence in the project’s achievability and accuracy? 
  • Would the project have taken place even without the initial investment? If it would have, then it cannot be considered a genuine offset. 

And that will be all from me for now, I hope you have found this helpful as you navigate the world of carbon pledges, policies and greenwash! 


Vasudef Vasanthan 

MEng (hons) Mechanical Engineering student on placement as Climate Action Data Assistant 

Posted in: Student blog

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