Getting to Net Zero

This is the name I decided to call my new blog so for this second post I will explore the concept of net zero carbon emissions and what will be required to get there.

What Exactly Is Net Zero?

Since the start of the industrial revolution, global temperatures have been steadily rising. Climate scientists attribute this warming to the release of greenhouse gases (GHGs) such as carbon dioxide and methane. Of course these gases occur naturally but over the past 200 years our global economy has been heavily dependent on fossil fuels - coal, oil and gas. When we burn those fuels to produce heat for our homes or energy to power our transport and factories, they release GHGs into the atmosphere.

Some of these gases are naturally absorbed by trees and the vast oceans but we have been producing more than nature can deal with and these excess gases have gradually built up in the upper atmosphere and this results in the warming as the blanket of gases act like a giant duvet trapping heat.

In 2015 at COP21 held in Paris there was a historic agreement when all 196 nations in the world pledged to keep global temperatures to well below 2.0C above pre industrial levels and preferably 1.5C and to limit the amount of GHGs to a level that nature can naturally absorb. This is what is meant by net zero emissions.

If we can get these GHGs into balance where the gases going into the atmosphere are aligned with those being naturally removed then global warming will stop. But until we get to this point the warming will continue.

Has Progress Been Made Since Paris?

When the Paris Agreement was signed back in 2015, the projections for reaching 1.5C were 2045. At that time the world had reached 1.0C above pre industrial levels.

Unfortunately, just 9 years later and we are already at 1.4C with 2023 being the warmest year on record. We are rapidly approaching the 1.5C key threshold and the new challenge over the coming decade will be to limit the warming to below 2.0C.

To keep on track for net zero by 2050, we need to reduce global emissions by 45% (compared to a baseline of 2010) by 2030. Unfortunately we are currently on track to increase emissions by 9% by 2030 so clearly the collective pledges made at the COP meetings are not being turned into effective action.

It seems clear that, despite lots of warm words and promises at the annual COP gatherings, little progress has been made to address the climate crisis. The world is currently way off track to meet its stated ambition of achieving net zero emissions by 2050.

What are the Main Greenhouse Gases (GHGs)?

Over the past 200 years or so, the industrial revolution has transformed the living conditions of millions of people all around the world. At the heart of this revolution has been an increasingly heavy dependence on fossil fuels - mainly coal, oil and gas. These carbon-based fuels release that carbon when used to create the energy to heat our homes and power industry and transport.

The scale of these emissions has gradually increased due to an ever increasing world population and ever growing industrialisation as economies grow and affluence expands.

The main GHG is carbon dioxide (CO2) which accounts for around 75% of emissions. Once released, it remains in the atmosphere for very long periods...over 100 years.

Methane (CH4) accounts for around 15% of emissions. It is generated naturally in wetlands, oceans and termites for example but also from industrial activities such as the extraction and use of fossil fuels, intensive livestock farming and from the decomposition of organic waste from landfill sites. Although the volume is much less than for CO2, it is 50x more potent so is just as dangerous. Fortunately it only hangs around for 10 years or so not a century.

Another gas which is produced naturally in our soils and oceans is nitrous oxide (N2O) but again there are significant amounts resulting from fossil fuels and the widespread use of nitrogen fertilisers in agriculture.

Finally hydroflurocarbons (HFCs) represent around 2% of greenhouse gases but their impact on global warming can be 2,000 times greater than CO2. They are mainly used in refrigeration and air conditioning processes.

Despite the pledges made at the landmark Paris Agreement in 2015, carbon emissions from fossil fuels continue to increase year on year resulting in more and more global warming. CO2 levels are the highest they have been for at least the past 800,000 years...currently 425ppm.

Currently 425ppm  credit NOAA Mauna Loa, Hawaii
(click to enlarge)

So, getting to net zero will be a huge challenge for humanity...but the alternative is surely unthinkable. The global climate crisis poses an existential threat to life as we have known it for many thousands of years and the the collective effort to stop global warming is the defining challenge of this generation...the next generation will be too late. We have the next decade to find a way to phase out fossil fuels and transition to cleaner energy sources such as wind, solar and hydro and make fundamental changes to the way we organise our everyday lives.

In a future article I will take a look at the role of the fossil fuel industry and the many ways they use to block policies to tackle the climate crisis and maintain business as usual.

Feel free to comment below on any thoughts you may have in relation to this article or climate change in general...thanks for reading.