November 2

Journey to Net Zero – a COP26 explainer

Focus on climate change has grown steadily globally and within Australia, especially within the last few years. As we have approached the global climate summit in Glasgow this week, there has been a lot of talk about "net zero".

So, why is that, and what does it mean? Here's a little explainer to get you across the most important facts!

This is the first article in a series - The Net Zero Carbon Transformation and your Business. Check out the next ones when you're done:

2. What do climate change goals have to do with business?

3. Carbon Reduction Guide for Small Business

4. How to measure and offset your carbon footprint

What does net zero mean?

Net zero refers to the fact that we need to balance the carbon budget, that is, stop emitting more atmosphere-warming gases than the earth absorbs. We need to reduce absolute emissions of these gases and remove the remainder from the air in order to avoid worsening change to global climate systems.

What is the problem with greenhouse gases?

It is well known that certain chemical compounds cause heat from the sun to get trapped in the earth's atmosphere instead of dissipating into space. This is called the greenhouse effect, and the compounds that cause it are called greenhouse gases (GHGs), including the well-known carbon dioxide (CO2) but also methane (CH4), nitrous oxide (N2O), and fluorinated gases (HFC, PFC).

A certain amount of the first three gases exists in the atmosphere naturally, but they exist in equilibrium, just the right amount to keep our planet at the healthy temperature that has allowed biodiversity to thrive and created the stable climate we have known for centuries.

Like many other environmental cycles, these gases are emitted by natural sources like respiration, decomposition and volcanic activity, and are likewise absorbed by other natural "sinks" like vegetation and the ocean. We have been adding far more of these gases to the environment than it can absorb for decades, and it is adding up.

In fact, the amount of carbon dioxide in the atmosphere has reached 413ppm, greater than the baseline level of 278ppm that was stable from the start of the 'common era' (0 CE) until the industrial revolution. Similar increases are recorded (via glacial ice analysis) for CH4 and N2O. 

Charts of CO2, CH4, N2O and temperature increase

How are these gases translating to climate change?

This increased concentration has already increased global average temperatures by over 1°C. We have already seen the effects of this in increased severity and frequency of weather events such as cyclones, droughts, bushfires and floods, including here in Australia.

Due to their delayed effect, the amount of GHGs that have already been emitted has already locked in further warming, up to 1.5°C higher than average in the next few decades. That might not sound like a lot, but it is enough to throw delicately balanced natural systems off, including continued worsening of extreme temperature and weather events, sea level rise of up to 77cm, and ecosystem and species loss. You can see more detail of what's predicted at 1.5° and 2°C here.

According to IPCC, each additional fraction of a degree of warming brings us closer to serious thresholds of systems collapse such as ice sheet collapse, sudden changes in ocean circulation and climate patterns, which can lead to a cascade of other impacts. Governments have agreed that in order to avoid these catastrophic impacts and have a chance of reversing the damage, we need to keep climate change to as close to 1.5 degrees as possible.

What do we need to do?

According to scientists, our best chance of avoiding the worst of climate change is to peak global greenhouse gas emissions and start reducing them as soon as possible, within this decade (by 2030 at the latest). We then need to minimise them as much as possible and remove from the atmosphere any emissions it can't avoid by 2050.

This will look slightly different for key industries. The global energy sector will need to act faster than the rest, reaching zero by 2040, partly because electricity generation contributes 25% of GHGs and also because proven low-carbon generation and storage technologies already exist.

The International Energy Agency has stated that in order to achieve net zero, there should be no new investment in coal or gas, fossil fuel use should be halved by 2035, and all unabated (without carbon capture and storage) coal and oil power plants should be phased out by 2040.

What is the Paris Agreement?

The Paris Agreement or Paris Accord is a legally binding international treaty on climate change adopted at the 21st Conference of the Parties (COP21) to the United Nations Framework Convention on Climate Change (‘UNFCCC’) in Paris in 2015 by all 197 parties.

The landmark agreement committed those nations work together to limit global warming to well below 2°C, preferably to 1.5°C, compared to pre-industrial levels. In order to achieve that limit, greenhouse gas emissions would need to peak as soon as possible and achieve a net zero state by mid-century.

What is happening in Glasgow?

As part of the Paris Agreement, countries agreed to provide an update on their progress every 5 years. That was scheduled to happen in 2020, but was delayed due to COVID-19. Glasgow is the 26th Conference of the Parties (COP26).

So far, the carbon reductions that have been committed to by individual countries (known as nationally determined contributions, or NDCs) have been inadequate to achieve the stated goal, only enough emissions reduction to limit us to 2.7°C warming according to the Emissions Gap Report.

A majority of countries have only committed to far-away targets, e.g. by 2050 or longer, without any commitments to the steep cuts we need this decade in order to achieve them. And their actual policies and action plans in place to achieve their goals are farther behind still. See more on individual country commitments.

During the conference, parties will negotiate how to reduce this further, including pressuring those countries that are not doing enough, and other implementation details. Key focuses will be setting short-term, 2030 reduction targets and providing climate finance to help poorer countries transition and adapt.

Global warming projections chart

What does this have to do with businesses?

Much of the above has been an issue for scientists and governments, but businesses are acting too. We will explore why and how in the next article in this series.

About the author 


I believe in the power of small business to have mighty impact. After 15 years driving sustainability in corporates and government, I am bringing my expertise to support small businesses - those with the passion, innovation and agility to tackle the world's greatest challenges.


climate change, net zero, science

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