Your COP26 jargon buster

Helping you make sense of sustainability.

Our guide to un-buzzing those buzz words

With the great and the good gathering in Glasgow for COP26 soon, green issues have never been higher on the agenda. But buzzwords abound when talking about things like climate change, net zero and decarbonisation, so it can be quite confusing to know what’s what.

We’re here to help, so we’ve compiled this jargon-buster to help you make sense of sustainability.


The United Nations Climate Change Conference is also known as COP. In 1992, 154 states signed a treaty to cut greenhouse gas emissions (more on these later!). These signatories are known as Parties to the Convention, and COP stands for Conference of the Parties. The first COP was in Berlin in 1995, and the 26th takes place in Glasgow from 31st October to 12th November 2021.

The Paris agreement

COP21 was held in Paris in 2015, and was a truly historic moment because that’s where the Paris Agreement was negotiated. For the first time ever, almost every country on earth agreed to work together to limit global warming to well below two degrees, and aim for 1.5 degrees, by committing to bring forward national plans to reduce carbon emissions.

They also agreed that the plan would be updated every five years to reflect their highest possible ambition at that time. COP26 is crucial because it’s the first update since Paris.

Carbon dioxide or CO2

Carbon dioxide gets a bad rep, but it’s just a natural gas that’s harmless in small quantities. It’s what we breathe out, after all! Burning fossil fuels also creates carbon dioxide in much larger quantities, and it becomes a problem when there is too much of it in the atmosphere.

Trees absorb carbon dioxide and turn it into oxygen through a process called photosynthesis. Right now, because we’re cutting down the trees that absorb CO2 and still burning fossil fuels to create energy, CO2 levels are seriously out of balance.

Fossil Fuels

These occur through natural geological processes and include coal, crude oil, natural gas. They’re formed from the decomposing remains of plants and animals that lived millions of years ago.

Climate change

Gases like carbon dioxide trap heat from the sun’s rays inside the earth’s atmosphere, causing the planet’s average temperature to increase. This in turn leads to other changes, such as rising sea levels, melting glaciers, heavier storms, and more frequent droughts. This happens naturally over millions of years, but human activity is speeding up the process at an unsustainable rate.

We’re seeing the effects all over the world. For example, the devastating heatwaves in Canada in summer 2021 where temperatures reached a whopping 49.6 degrees. And the widespread Australian Bushfires in 2019-2020. Climate experts are clear that we’ll continue to see these extreme weather events like fires, severe storms and flooding start earlier and last longer, so we must act. Fast.

Carbon emissions

This refers to CO2 being released into the atmosphere, where it stays for a very long time. Over the last few decades, we’ve added CO2 to the atmosphere at such a rate on average - 1.5% a year for the past decade - that the earth’s ‘blanket’ is getting thicker and the world is heating up. 

Greenhouse gases

CO2 isn’t the only gas that causes this ‘greenhouse effect’ of heating the planet – others major ones include methane, nitrous oxide (N2O) and ozone. And because of our rising population and our energy-guzzling lifestyles, these emissions are unsustainable too. For instance, livestock farming is the biggest source of methane emissions in the world and contributes to over 14.5% of global greenhouse gases – so opting to eat less meat or go vegetarian or vegan can be dramatically better for the environment.

Trees absorb carbon dioxide and turn it into oxygen.

Net Zero

Put simply, this means achieving a balance between the carbon emissions released into the atmosphere, and the carbon removed from it. 

For nations and businesses, this could be achieved by using more renewable energy, offsetting emissions by planting trees, and investing in environmental projects such as restoring natural landscapes like peatlands that can absorb and store carbon.

What does it mean to us individuals in our daily lives? Well, 40% of the UK’s emissions come from our homes, so by powering them in more energy-efficient ways we can make a big difference. Swapping to more fuel-efficient boilers, installing smart meters, and switching to electric vehicles are all ways of helping reach Net Zero.

Net Zero target

In June 2019, the UK became the first major economy to set a target to reach Net Zero emissions by 2050. Since then another 59 countries have set similar goals, including the United States and China who the world’s biggest contributors to climate change.

For countries to reach their targets, organisations must rapidly reduce their carbon emissions while also investing in projects to remove greenhouse gases from the atmosphere. At British Gas we aim to beat the target and get to Net Zero by 2045 with our People and Planet Plan.

Carbon neutral

Being carbon neutral means that any carbon emissions are offset. So, a business that pledges carbon neutrality isn’t necessarily reducing its emissions but rather balancing them out – typically by planting more trees or investing in tech that captures and stores carbon.

Zero carbon

If something is zero carbon, it means it results in no carbon emissions in the first place, so no carbon needs to be captured or offset. For example, a zero-carbon energy tariff doesn’t use any fossil fuels in its production.

Carbon negative

This takes that idea of carbon neutrality one step further. You are carbon negative if the amount of CO2 emissions you remove from the atmosphere is bigger than the amount of CO2 emissions you put into the atmosphere. So being carbon negative is actually a very positive thing. It means you’re actively doing something to better the climate.

Carbon capture

With clever technology, it’s possible to stop the carbon dioxide created by factories and power plants from reaching the atmosphere and contributing to climate change. Filters fitted to chimneys can capture the carbon emissions before they escape, and they can then be piped to places where they can be used or stored. Some can be used to make plastic or grow greenhouse plants, but most is injected deep underground – where fossil fuels come from – to be stored.

Carbon footprint

Each of us creates a carbon footprint with our activities. It refers to the amount of carbon dioxide released into the atmosphere as a result of what we do, and applies to groups, nations, and organisations as well as individuals. From the food we buy to the flights we take and the homes we heat, almost everything we do will have an impact on our carbon footprint. Offsetting actions, like planting trees, will help to reduce your carbon footprint.

Switching to renewable energy sources helps reduce your carbon footprint.


This is the process by which we reach Net Zero, through reducing, eliminating and offsetting carbon emissions. Whether you run a large organisation or live in a small flat, it’s something we can all play a part in by switching to renewable energy sources rather than relying on fossil fuels to power.

As one of the biggest energy providers in the UK, British Gas will have a big part to play in the UK’s decarbonisation and our climate transition plan outlines our strategy to do that.

Renewable energy

Unlike fossil fuels. renewable energy comes from natural resources that are constantly replaced, like sunshine, wind, and water. Fossil fuels will eventually run out (certainly at the rate we’re using them) but the sun will keep shining, the wind will keep blowing and water will keep flowing. Renewable energy releases less CO2 than fossil fuels. In some cases, like wind and solar, they don’t emit any at all in the process of generating energy, only from their initial building and maintenance.


A renewable source of energy, biofuel is derived from plant or algae material or animal waste. For example, biodiesel is made from vegetable oil and liquid animal fats and burns when ignited, releasing energy to power things like cars - just like fossil fuels but much more cleanly.

Global warming

One of the key components of climate change, global warming is the gradual overall temperature increase of the of the earth's atmosphere. This is generally due to the greenhouse effect caused by increased levels of carbon dioxide, CFCs (Chlorofluorocarbons found in hairsprays and deodorants) and other pollutants.


If something is sustainable, it means it can be maintained at current levels.

In environmental terms, sustainability refers to how we make sure the planet’s natural resources are not depleted for future generations. And as individuals we can make changes at home too. Whether it’s smarter energy efficient technology or opting for tariffs that use more renewable energy sources, there are many ways to be more sustainable.

Ready to do your bit for the planet?

Since 40% of all UK emissions come from our homes 1, it really is the best place to start making a difference. So check out our green homes hub to find lots of easy ways we can help you use less energy and make your home more sustainable for the future.

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Additional information

  1. Emissions Infographic ( (PDF 363KB)