The Climate Lemon

The Ultimate Climate Change Jargon Buster

Reading about climate change is really confusing. It’s confusing for me, and I’ve been reading up on it, studying it and now working professionally on combating it, for years. God forbid what it must be like for a newcomer. I get really frustrated with how impenetrable and jargon-filled a lot of the content is.

On this blog I try to avoid jargon when a simple everyday term will do, and explain it straight away when a special term is the only accurate one to use. But what about all the other blogs and books that don’t shy away from the insider lingo?

Don’t worry – I’ve got you covered. I’m making a climate change jargon buster, just for you.

On this page, I’ll list climate change terms and explain them briefly in simple everyday language, while also linking to resources where you can learn more.

We’ll start at ground zero with terms like climate change, greenhouse gas emissions and carbon, and work up to the more complex stuff like carbon cap and trade markets and payments for ecosystem services.

Quick note: This resource is a work in progress! This is just the tip of the (rapidly melting) iceberg. I wanted to publish it now so I have something up for climate newbies to refer to (or even for those in the know to share with newbies) as waiting till it’s “finished” would take forever. I’ll be adding to this constantly, so save this page and check back.

Now, let’s dive in!

Climate change jargon buster


The long-term average weather conditions in a certain place over time.

You can talk about the climate of a country or region, or a whole planet. The climate system is affected by things like the temperature of the sun, the tilt of the Earth’s axis, how much light the Earth reflects into space, the currents of the ocean and the level of greenhhouse gases in the atmosphere.

Example: The UK has a mild and often soggy climate.

Learn more:

Video: The difference between climate and weather, explained by Neil deGrasse Tyson

Climate change

A substantial gradual shift, or change, in the climate.

Usually used to mean shift in the global climate, but technically could refer to a regional or local climate. When sceptics and deniers say the climate has always changed, they’re actually correct. However natural climate change takes a very very long time, and humans simply didn’t exist when the Earth’s climate was much different to its current state. When people say climate change, they usually mean human-caused global climate change.

Example: Burning fossil fuels causes climate change.

Learn more:

Global warming

The gradual increase in global average temperature.

The word average is key here. It does not mean everywhere all over the globe will get hotter every day. It does not mean nowhere will be cold anymore, or that winter won’t happen. The planet is huge and there is a very wide range of temperatures, from the freezing Arctic to the baking deserts to the mundane mildness of England. But the average global temperature has increased about 1.1 degrees celsius since the Industrial Revolution. Climate change is broader and refers to not just global warming but the associated impacts like extreme weather, changes to the seasons, melting glaciers and ice caps, ocean acidification and sea level rise. (Don’t worry we’ll get to all of them). But for decades the two terms have been used more or less interchangeably, though with different connotations.

Example: We need to keep global warming to below two degrees.

Fossil fuels

This is a straightforward one: coal, oil and gas.

These three fuels are called fossil fuels because they’re made of fossilised ancient organic matter – stuff like sticks and shells – which has decayed and then been exposed to heat and intense pressure in the Earth’s crust for hundreds of millions of years. They contain a lot of energy and carbon, which is released when burnt. The discovery of fossil fuels powered the Industrial Revolution. While they’re technically being created all the time, they’re finite in human terms because the process takes many millions of years.

Example: Fossil fuels were hot in the twentieth century but now we need to move on.

Learn more:

Video: 300 years of fossil fuels in 300 seconds, by Post Carbon Institute

Article: A Brief History of Human Energy Use, by the Atlantic 


A chemical element on the periodic table with the symbol C, which is the basic building block of life on Earth.

carbon climate change jargon buster
All plants and animals are partly made of it and the carbon cycle is vital to life on Earth. It’s one of the most common elements in the human body, the Earth and the universe, which originally comes from the burning hearts of stars. (Poetic AF but it’s true). Although carbon is natural and necessary to life, when discussing climate change it has a negative meaning because it’s shorthand for the excessive amounts of carbon dioxide which we’re putting into the atmosphere which is messing up the natural carbon cycle and causing climate change.

Example: Coal, diamonds and my pet tortoise are all made of carbon.

Learn more: 

Wikipedia page for carbon

PDF: The carbon cycle, a brief introduction 

Carbon dioxide / CO2

A gas made of a carbon atom combined with two oxygen atoms, aka CO2.

Like carbon there’s nothing innately bad about carbon dioxide. It’s totally natural and in fact vital for all life, as plants require it and animals require plants. And without a certain amount of it in the air, the planet would be a freezing snowball. We need just the right amount, and too much is bad. The problem is humans are massively increasing the levels of carbon dioxide in the atmosphere, which is causing climate change. This is because carbon dioxide is a greenhouse gas which is very effective at trapping heat, and it stays in the atmosphere for a very long time.

Example: Plants use carbon dioxide for photosynthesis

Carbon dioxide equivalent / CO2e

A metric to describe how much climate change a bundle of gas emissions would cause.

Carbon dioxide is not the only greenhouse gas, but it is the most common one. The different gases stay in the atmosphere for different lengths of time and absorb different amounts of heat. These two differences make up the ‘global warming potential’ of the gas – how much warming they would cause over say 100 years. For simplicity, when people are talking about greenhouse gas emissions, rather than listing a bit of this and a bit of that and all the stats to go with each, they often convert them into the amount of carbon dioxide that would have the same impact: the carbon dioxide equivalent.

Example: In 2009 the UK’s emissions were 566 million tonnes of CO2e.

Learn moreWhat are CO2e and global warming potential (GWP)? 

Greenhouse gases

A group of gases that, due to their chemistry, trap heat and warm up the Earth’s climate via the greenhouse effect.

The most common one is carbon dioxide (CO2) and others include methane (CH4), Nitrous oxide (N2O), Ozone (O3), and even water vapour (H2O) – though that is totally fine on its own: it’s increasing the levels of the others that’s the problem.

You might also come across the funky sounding Chlorofluorocarbons (CFCs) and Hydrofluorocarbons (incl. HCFCs and HFCs).

Greenhouse gas emissions

Releasing any of these greenhouse gases into the air is known as greenhouse gas emissions, sometimes shortened to GHG emissions.

The most obvious source of GHG emissions is the billowing smoke coming from factories and power plants. Other sources include car exhausts, landfill sites, forest fires and industrial animal farming, via the flatulence of cows.

Example: We need to ultimately reduce net greenhouse gas emissions to zero to address climate change.

Greenhouse effect

The process where greenhouse gases in the atmosphere trap some of the sun’s heat and stop it radiating back out to space, making the planet warmer than it would be otherwise. Like an insulating blanket around the planet.

Like carbon, remember that the greenhouse effect is not bad. It’s natural and actually necessary for life on Earth. Without it, the planet would be freezing. And it’s not controversial: the greenhouse effect has been understood for a long time and is based on very basic physics.

It was in a perfect balance. But all the extra greenhouse gases we’ve been putting into the air since the Industrial Revolution has thrown it out of whack and caused it to go into overdrive, overheating the planet.

Paris Agreement

Also known as the Paris Accord or just the Paris climate deal, it is the first globally binding agreement on tackling climate change. It was signed in December 2015 in Paris. All the world’s countries have signed it, but Trump says he intends to pull the USA out.

Kicking off in 2020, the Paris Agreement is based around each country submitting a national action plan for addressing climate change, which have to be made progressively more ambitious. We’re supposed to get to zero net emissions in the second half of the century and the overarching aim is to keep global warming to well below 2 degrees, and to make efforts to keep it to 1.5 degrees.

Example: We need national governments, cities and businesses to work together to achieve the Paris Agreement.

Learn more: So what actually is the Paris Agreement on climate change?


The Intergovernmental Panel on Climate Change, shortened to IPCC, is the world’s leading authority on climate science. It’s role is to provide an objective and rigorous factual basis to inform climate politics and action.

It was set up in 1988 by The UN Environment Program and the World Meteorological Organisation, in order to assess the scientific research on climate change, it’s risks and impacts, possible ways of reducing it (known as mitigation) and adaption to it. Thousands of scientists from all over the world contribute to the IPCC on a voluntary basis. The IPCC does not conduct any on-the-ground research itself, but assesses huge volumes of recent published scientific papers in order to produce their reports.


The United Nations Framework Convention on Climate Change, aka the UNFCCC, is the part of the UN that deals with climate change. They are the ones that organise the annual climate summits and the Paris Agreement.

The UNFCCC came into force in 1994, sparked by the influential 1992 Rio Earth Summit that also spawned other environmental global Conventions on biodiversity and desertification. Now, 197 nations are committed to the UNFCCC. These countries are called Parties to the Convention – which is where the annual UN climate summits get their odd ‘COP23′, COP24’ etc names from. Those stand for the 23rd Conference of the Parties and 24th Conference of the Parties respectively. So clear, right?

Learn more: The UNFCCC’s website.


A prefix for something that emits only a small amount of carbon emissions, or less than the alternative.

For example low-carbon transport could include public transit and hybrid cars, and low-carbon energy includes renewables of course and gas and nuclear are often labelled as low-carbon too. (Gas is a fossil fuel and emits carbon, but much less than oil and dramatically less than coal. Nuclear doesn’t emit carbon but has other serious environmental problems of its own).

Zero carbon / net zero carbon

Like low-carbon, but better. A prefix for something that doesn’t emit carbon emissions at all. For example walking and cycling aren’t just low-carbon transport, they’re zero-carbon.

Net zero carbon means that some carbon is emitted, but only an equal amount to what is absorbed, so the net effect is carbon neutral. A good example is burning wood for energy: it emits carbon, but only the same amount as the trees previously absorbed when they were alive.

Most of the time when people talk about zero carbon, they really mean net zero carbon.

Example: The Paris Agreement says the global economy needs to be net zero carbon in the second half of this century.

Learn more: Zero Carbon Britain: Making it Happen (report from Centre for Alternative Technology).

Climate mitigation / adaptation

There are two types of climate action: mitigation and adaptation. They aren’t mutually exclusive though, one action can be both.

All action taken to prevent, reduce, slow down, stop or reverse climate change is climate mitigation. This is mostly through cutting emissions, for example renewable energy, electric vehicles, energy efficiency. And tree planing and carbon storage (more on that later) also count.

Mitigation is key, but climate change is already having impacts, and some level of future impact is already ‘locked in’ by the greenhouse gases already in the atmosphere (as they take many years to finish having their effect). All action to prepare for these impacts and make them more bearable is climate adaptation. For example flood defences and drought-resistant crops.

Two degrees / 2C

Two degrees Celsius has long been the de facto speed limit for climate change, the cutoff point for the ‘safe level’ after which truly disastrous effects are expected. The Paris Agreement has the goal of staying well below 2C, and pursue efforts to keep to 1.5C. We’ve already reached 1.1C, by the way.

There’s lots of interesting debate around the two degrees limit and how feasible it is, and how safe it actually is (hence the mention of the more ambitious 1.5C target).

Learn more:

Article: Why is climate change’s 2 degrees Celsius of warming limit so important?

Article: Two degrees: The history of climate change’s speed limit

Your turn

Suggest a jargon term to be busted! Did I miss something you need to know about? Let me know on Twitter or email and I’ll add it in. I’ve got a bunch more terms I’m already planning to add, but if you suggest it I’ll bump it up the priority list.

Please share this post with anyone who’s new to the topic and wants an easy introduction to these confusing terms.

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Hey, I’m Tegan

I'm a passionate sustainability enthusiast, blogger and communications professional. I live in Brighton, UK, with my boyfriend and tortoise. Can usually be found reading, writing or eating chickpea burritos. Wanna chat? I'm at @TeganTallullah on Twitter.

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