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The UK is comitted to net zero by 2050.  Oxford city to net zero by ten years earlier, 2040.

But what does ‘net zero’ actually mean?  And is it better than going ‘carbon neutral’ or even ‘carbon positive’/’carbon negative’?

And what is Oxford doing to meet its 2040 commitment?


Back in September, we were lucky enough to catch a really clear, jargon-busting presentation by Andrew Griffiths from Planet Mark, on the organisation’s pre-COP26 tour.  Find a video of him explaining net zero and more at the end of this post.

Here’s a written summary of some of the key learning:

True zero is when a company/country/(individual) emits NO Co2e emissions, so they have reduced their emissions from whatever they are now to absolutely none, over a period of time.

Net zero acknowledges that getting to true zero is impossible for most e.g., if making a product or offering a service.   You cannot avoid some emissions, and these are called unavoidable emissions.

When reducing emissions as much as possible, there is a gap between the true zero you may aim for and the net zero reality.

To become net zero, you get as close as you can to true zero and then offset the rest of your emissions – i.e. the unavoidable emissions, the difference between where you have got to and true zero.  This last little bit is usually less than 10% of where you began emissions-levels-wise.

The offsets used to tackle the last bit must be carbon removal offsets (there are other types of offset, as you can see below).

To become carbon neutral you are allowed to offset all of your emissions (in contrast to only the <10% of unavoidable emissions to be net zero), so it does not mean you are making any reductions to your own emissions.  You can simply carry on as usual and pay someone else to do something to reduce carbon elsewhere, calling yourself carbon neutral as soon as you have paid for offsets.   In contrast, net zero cannot be achieved overnight.

Furthermore, the offsets for carbon neutrality can be either avoidance offsets or the more active removal offsets necessary for net zero status.

Active carbon removal offsets mean putting in measures that actively pull or absorb greenhouse gases out of the atmosphere, either by doing it yourself or paying someone else to do it, anywhere in the world.  Examples include planting trees and seagrass, and basically making photosynthesis happen (the process whereby plants absorb CO2, sunlight and water to produce energy and oxygen).

Avoidance offsets are activities the reduce emissions by preventing their release into the atmosphere – for example investing in solar, to avoid fossil fuels being burnt; stopping grasslands being changed to croplands etc. – so they reduce emissions by making something happen which might not otherwise have happened if the normal course of action was take.

Getting to net zero can only be done using carbon removal offsets for unavoidable Scope 3 emissions.

Meanwhile, carbon neutrality can be achieved by any kind of offset.

This language is used primarily for GHG (greenhouse gas emissions) accounting for companies or entities like geographical regions rather than individuals, but can be useful when thinking about the emissions you are responsible for on an individual basis.

Scope 1 emissions are the emissions you (as an individual/business/geographical region) produce directly in the day-to-day (e.g. from vehicles).  Scope 2 emissions are the indirect emissions from what you do – e.g. from the electricity you purchase, made by burning fossil fuels.

To be net zero, emissions for Scopes 1 & 2 need to go to ZERO.

Scope 3 is everything else – all the indirect emissions from supply chains, produced in the making of the stuff you buy, waste disposal etc.

To get to net zero, you need to get Scope 3 as close to zero as possible (no more than 10% of your original emissions), so it is only the unavoidable emissions left.

These residual/unavoidable Scope 3 emissions are what you then offset using accredited CO2e removal schemes.

You can read more about Scope 1, 2 & 3 emissions here on the Anthesis website.

Carbon negative or positive actually mean the same thing and are simply an add-on to being carbon neutral.  All that it means is that you have purchased offsets beyond your own emissions.  You may still be emitting exactly as you were when you became carbon negative, positive or neutral, but are offsetting those emissions.

The sooner we achieve net zero emissions worldwide, the less severe the consequences of climate change.

Going carbon neutral/positive/negative is useful but only as a step to net zero.

You could argue that some entities are taking advantage of the lack of public understanding of different terms to make it look like they are taking sufficient serious action to mitigate climate change, by going carbon neutral, when this is nowhere near sufficient in the longterm.  Net zero is what we need!

One of only countries to have set a net zero target.

UK target: Net zero by 2050; 70% reduction by 2035

Oxford target: Net zero by 2040, 10 years before obliged under UK law.

Step 1: measure where you’re starting from – understand your baseline, and then come up with a target that is ambitious enough and realistic enough for you to achieve.

For individuals, this can be done by completing a carbon footprint.  LCWO has developed a carbon footprint you can complete yourself using an excel spreadsheet, complete with user guide.  Download the LCWO Quicksilver Carbon Footprint Calculator and guides here.

For businesses, you could start with a free energy audit. In Oxfordshire, SMEs (small to medium enterprises, 10-250 employees) can benefit from a free energy audit via OxFutures.

To achive Oxford City’s net zero committment, a group of Oxford’s largest and most significant organisations (universities, councils, hospitals…) have come together as the Zero Carbon Oxford Partnership (ZCOP), and worked with the Carbon Trust to create the Zero Carbon Oxford Roadmap and Action Plan.

Here’s a short video about that:

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