The Times Australia
The Times World News

.
The Times Real Estate

.

The climate impact of plastic pollution is negligible – the production of new plastics is the real problem

  • Written by Karin Kvale, Senior Scientist, Carbon Cycle Modeller, GNS Science
A mechanical claw grabbing pile of mixed plastics at a waste treatment plant.

The dual pressures of climate change and plastic pollution are frequently conflated[1] in the media[2], in peer-reviewed research[3] and other environmental reporting[4].

This is understandable. Plastics are largely derived from fossil fuels[5] and the burning of fossil fuels is the major driver of human-caused climate change[6].

The window for cutting emissions to keep warming at internationally agreed levels[7] is closing rapidly and it seems logical to conclude that any “extra” fossil carbon from plastic contamination will be a problem for the climate.

Our research[8] examines this question using an Earth system model. We found carbon leaching out of existing plastic pollution has a negligible impact. The bigger concern is the production of new plastics, which already accounts for 4.5% of total global emissions[9] and is expected to rise.

Organic carbon leaching from plastic pollution

In nature, plants make organic carbon (carbon-hydrogen compounds) from inorganic carbon (carbon compounds not bonded with hydrogen) through photosynthesis. Most plastics are made from fossil fuels, which are organic carbon compounds. This organic carbon leaches into the environment from plastics as they degrade.

Concerns have been raised[10] that this could disrupt global carbon cycling by acting as an alternative carbon source for bacteria, which consume organic carbon.

A key assumption in these concerns is that organic carbon fluxes and reservoirs are a major influence on global carbon cycling (and atmospheric carbon dioxide) over human timescales.

It is true that dissolved organic carbon is a major carbon reservoir. In the ocean, it is about the same amount as the carbon dioxide (CO₂) held in the pre-industrial atmosphere. But there are key differences between atmospheric CO₂ and ocean organic carbon storage. One is the climate impact.

Atmospheric CO₂ warms the climate directly, whereas dissolved organic carbon stored in the ocean is mostly inert. This dissolved organic carbon reservoir built up over many thousands of years[11].

A broken plastic cup with a plant stuck in it floats in the ocean.
Carbon leaching from plastics is mostly used rapidly by bacteria. Sebnem Coskun/Anadolu Agency via Getty Images[12]

When phytoplankton make organic carbon (or when plastics leach organic carbon), most of it is rapidly used within hours to days by bacteria and converted into dissolved inorganic carbon[13]. The tiny fraction of organic carbon left behind after bacterial processing is the inert portion that slowly builds up into a natural reservoir.

Once we recognise that plastics carbon is better considered as a source of dissolved inorganic carbon, we can appreciate its minor potential for influence. The inorganic carbon reservoir of the ocean is 63 times bigger than its organic carbon store.

Plastics carbon has little impact on atmospheric CO₂

We used an Earth system model to simulate what would happen if we added dissolved inorganic carbon to the surface ocean for 100 years. We applied it at a rate equivalent to the amount of carbon projected to leach into the ocean by the year 2040 (29 million metric tonnes per year[14]).

This scenario likely overestimates the amount of plastics pollution. Current pollution rates are well below this level and an international treaty to limit plastic pollution[15] is under negotiation.

Read more: Four reasons to be hopeful about the planned global plastics treaty[16]

We repeated the model simulation of adding plastics carbon both with strong climate warming (to see if plastics carbon might produce unexpected climate feedbacks that increase warming) and without (to see if it could alter the climate by itself). In both cases, plastics carbon only increased atmospheric CO₂ concentrations by 1 parts per million (ppm) over a century.

This is a very small increase, considering that current burning of fossil fuels is raising atmospheric CO₂ by more than 2ppm each year[17].

A mechanical claw grabbing pile of mixed plastics at a waste treatment plant.
Limiting plastic incineration would help reduce emissions from plastic waste. Shutterstock/zlikovec[18]

Direct emissions from burning plastic

We also examined the impact of plastics incineration. We used a scenario in which all plastic projected to be produced in the year 2050 (1.1 billion metric tonnes[19]) would be burned and directly converted into atmospheric CO₂ for 100 years.

In this scenario, we found atmospheric CO₂ increased a little over 21ppm by the year 2100. This increase is equivalent to the impact of fewer than nine years of current fossil fuel emissions.

Relative to the current continued widespread burning of fossil fuels for energy, carbon emitted from plastic waste will not have significant direct impacts on atmospheric CO₂ levels, no matter what form it takes in the environment.

However, plastics production, as opposed to leaching or incineration, currently represents about 4.5% of total global emissions[20]. As fossil fuel consumption is reduced in other sectors, emissions from plastics production are expected to increase in proportional footprint[21] and absolute amount[22].

Read more: Oil companies are ploughing money into fossil-fuelled plastics production at a record rate – new research[23]

A legally binding plastics pollution treaty, currently under development[24] as part of the UN’s environment programme, is an excellent opportunity to recognise the growing contribution of plastics production to climate change and to seek regulatory measures to address these emissions.

Limiting the use of incineration is another climate-friendly measure that would make a small but positive contribution to the goals of the Paris Agreement[25].

Of course, environmental plastics pollution[26] has many negative impacts beyond climate effects. Our work does not diminish the importance of cleaning up plastic pollution and implementing stringent measures to prevent it. But the justification for doing so is not primarily grounded in an effort to cut emissions.

References

  1. ^ conflated (www.bbc.co.uk)
  2. ^ media (www.bloomberg.com)
  3. ^ research (www.sciencedirect.com)
  4. ^ environmental reporting (www.weforum.org)
  5. ^ derived from fossil fuels (www.science.org)
  6. ^ major driver of human-caused climate change (www.globalcarbonproject.org)
  7. ^ internationally agreed levels (www.globalcarbonproject.org)
  8. ^ research (www.facetsjournal.com)
  9. ^ 4.5% of total global emissions (www.nature.com)
  10. ^ Concerns have been raised (www.sciencedirect.com)
  11. ^ many thousands of years (www.annualreviews.org)
  12. ^ Sebnem Coskun/Anadolu Agency via Getty Images (www.gettyimages.com.au)
  13. ^ dissolved inorganic carbon (www.annualreviews.org)
  14. ^ 29 million metric tonnes per year (www.science.org)
  15. ^ international treaty to limit plastic pollution (www.unep.org)
  16. ^ Four reasons to be hopeful about the planned global plastics treaty (theconversation.com)
  17. ^ more than 2ppm each year (essd.copernicus.org)
  18. ^ Shutterstock/zlikovec (www.shutterstock.com)
  19. ^ 1.1 billion metric tonnes (www.sciencedirect.com)
  20. ^ 4.5% of total global emissions (www.nature.com)
  21. ^ proportional footprint (www.sciencedirect.com)
  22. ^ absolute amount (www.science.org)
  23. ^ Oil companies are ploughing money into fossil-fuelled plastics production at a record rate – new research (theconversation.com)
  24. ^ development (www.unep.org)
  25. ^ Paris Agreement (unfccc.int)
  26. ^ environmental plastics pollution (www.science.org)

Read more https://theconversation.com/the-climate-impact-of-plastic-pollution-is-negligible-the-production-of-new-plastics-is-the-real-problem-207813

The Times Features

From Classic to Contemporary: 5 Timeless Costumes for Any Party

When it comes to dressing up for a costume party, you want to choose something that is not only fun but also memorable. Whether you're attending a Halloween event, a themed gathe...

Action Figures as Art: The Growing Trend of Custom Figures and Modding

Action figures have long been regarded as collectible items, valued by enthusiasts and fans for their connection to popular culture. However, in recent years, a growing trend has...

The Ultimate Guide to Securing Grants for Your Small Business in Australia

Running a small business in Australia comes with both opportunities and challenges. While it can be rewarding, funding your business through the early stages or periods of growth...

Men’s Guide to Styling Suits with Sweaters for the Ultimate Winter Look

Winter brings a unique set of challenges when it comes to maintaining a sharp and stylish wardrobe. While suits are a staple of a well-dressed man’s closet, staying warm during t...

Discover the Charm of a Girl's White Dress

Key Highlights Timeless elegance: White dresses feel pure and have classic charm. They are perfect for many types of events. Versatile styles: You can pick from lace, embroid...

Top Medical Grade Red Light Therapy Devices in Australia

Key Highlights Lumitter™ has advanced red light therapy devices that combine new ideas with wellness. Red light therapy helps lower pain and swelling and boosts skin health. ...

Times Magazine

The Essential Guide to Transforming Office Spaces for Maximum Efficiency

Why Office Fitouts MatterA well-designed office can make all the difference in productivity, employee satisfaction, and client impressions. Businesses of all sizes are investing in updated office spaces to create environments that foster collaborat...

The A/B Testing Revolution: How AI Optimized Landing Pages Without Human Input

A/B testing was always integral to the web-based marketing world. Was there a button that converted better? Marketing could pit one against the other and see which option worked better. This was always through human observation, and over time, as d...

Using Countdown Timers in Email: Do They Really Increase Conversions?

In a world that's always on, where marketers are attempting to entice a subscriber and get them to convert on the same screen with one email, the power of urgency is sometimes the essential element needed. One of the most popular ways to create urg...

Types of Software Consultants

In today's technology-driven world, businesses often seek the expertise of software consultants to navigate complex software needs. There are several types of software consultants, including solution architects, project managers, and user experienc...

CWU Assistive Tech Hub is Changing Lives: Win a Free Rollator Walker This Easter!

🌟 Mobility. Independence. Community. All in One. This Easter, the CWU Assistive Tech Hub is pleased to support the Banyule community by giving away a rollator walker. The giveaway will take place during the Macleod Village Easter Egg Hunt & Ma...

"Eternal Nurture" by Cara Barilla: A Timeless Collection of Wisdom and Healing

Renowned Sydney-born author and educator Cara Barilla has released her latest book, Eternal Nurture, a profound collection of inspirational quotes designed to support mindfulness, emotional healing, and personal growth. With a deep commitment to ...

LayBy Shopping