The Sustainability group met on 6 May and 20 May. Based on several articles, our 6 May session continued discussions on how best to achieve net zero carbon gasses emissions from landscapes, both urban and rural. We also considered whether disruptions and social disturbances, such as the war in the Ukraine, will create long-term impediments to meeting global emissions goals by 2050. At a local level, we considered the achievement of a local farmer at Warrenbayne who has been awarded carbon neutrality status under a Meat and Livestock Australia scheme. We also examined which sectors are the biggest carbon emitters in Australia and how these emissions have been tracking over time.

At out 20 May session we discussed the relatively new science that aims to determine how much human emissions of greenhouse gasses (GHG) can be attributed to severe weather events and our future climate. Attribution science in this scenario makes extensive use of large-scale climate models called general circulation models that assess whether events are made more severe as a result of the presence of human generated GHG emissions. This is still a developing area of science and cannot be reliably used for all types of weather events. We also briefly considered the headline statements from the latest report from the Climate Mitigation working group of the Independent Panel on Climate Change (IPCC), which confirmed that without immediate (by 2030) and deep cuts to global GHG emissions, keeping global warming within the 1.5c to 2.0c range is unlikely to be achieved.

John Lane

Theme: How climate models are used to attribute human induced climate change to severe weather events and future climate projections

• We frequently hear in the media comments about how climate change is making extreme weather events worse as well as how human activity is affecting our changing climate.
• Comments about recent bushfires, floods, coral bleaching, tropical storms and polar ice melt events are often stated as being made worse by human caused climate change
• But what is the veracity of these claims given extreme weather events are inherently variable and other natural factors influence climate change.
• In relatively recent times scientists have adopted and applied the concept of ‘attribution’ to specific weather events and future climate projections.
• In this context attribution science attempts to determine the extent that human activity has contributed to severe weather events and climate change.
• Using climate models, attribution science attempts to determine how the severity of an event or future climate projections has/will be changed by human impacts.
• Following are links to several articles and a nine minute video on the subjects of attribution science and climate modelling.
• If time permits, we could also consider the latest ‘headline statements from the IPCC working Group 111 – Mitigation of Climate Change. A link to these statements also follows.

 
 
Colombia University – Attribution science : https://news.climate.columbia.edu/2021/10/04/attribution-science-linking-climate-change-to-extreme-weather/
 
Verisk  - Attribution Science: https://www.air-worldwide.com/publications/air-currents/2020/the-new-science-of-event-attribution/
 
CSIRO ECOS – Climate change attribution to severe weather events: https://ecos.csiro.au/climate-change-attribution/
 
Pacific Institute for climate solutions - climate models video: https://www.youtube.com/watch?v=bkcrH9tYv8g
 
MIT – What are climate models: https://climate.mit.edu/explainers/climate-models
 
BOM’s climate models - http://www.bom.gov.au/climate/ahead/about/model/access.shtml
 
IPCC working group 111 headline statements from the April 2022 report: https://www.ipcc.ch/report/ar6/wg3/resources/spm-headline-statements/

This week's session will be held this Friday, 6 May, beginning at 9:30 am. The theme will be: 'Achieving net zero CO2 (equivalent) emissions by 2050 in a turbulent world' 
 
Background

The New Scientist article indicates that the Ukraine crisis has generated a scramble for resources that is jeopardising the thrust for renewables and accelerating the increase in atmospheric CO2. Alternatively, sanctions imposed on Russia's gas pipe line may pave the way for the exit from hydrocarbons as the critical energy source.  
 
The CSIRO ECOS (link: https://www.csiro.au/Newsletters/ECOS/2022-04 ) article discusses the method use to determine how to meaure climate change attribution to specific severe weather events.  

The Benalla Ensign article showcases a local farmer who has achieved carbon neutrality under a scheme promoted by Meat and Livestock Australia. 
 
Frank Dunin’s paper considers the difficulty of measuring the take up of carbon in wooded ecosystems. 
 
Introduction 

• Urban communities with high population density that sponsor high traffic and industrial activity lead to concentrated sources of trace gas emission. Of major concern are two carbon gases, CO2 and CH4 because of heating capacity and having relatively long residence time in the atmosphere. Does Urban Planning have a role in mitigating carbon emissions such as venting methane for energy generation or effecting appropriate drainage around industrial sites? 
• Rural landscapes are characterised by the presence of green vegetation for extended periods. This presence is supported by Photosynthesis entailing the assimilation of CO2 predominantly from the atmosphere. This capacity for CO2 assimilation has attracted industrial enterprises to offset their carbon emissions in striving towards carbon neutrality by 2050. Wooded ecosystems appeal as effective agents for this offset. The capacity for legitimate offset is being questioned in wooded communities as to their effectiveness and raises the question of "Is carbon neutrality achievable by 2050"?   
• Tom Crocker's contribution of land capability survey with perturbations through land management becomes a valuable asset to judge whether urban emissions can be balanced with rural assimilation.   
• Judging ecosystem efficacy to offset urban emission require understanding of carbon balance of these systems and how they are distributed across the landscape.  

Who are the big GHG emitters in Australia? 

• Key groupings of GHG emission sectors consist of: 
  • Electricity 
  • Stationary energy (except electricity) 
  • Transport 
  • Agriculture 
  • Fugitive emissions 
  • Industrial processes 
  • Waste 
  • Land use, and use change and forestry (LULUCF) 
• What do they each proportionally contribute to Australia’s total GHG emissions? 

https://www.industry.gov.au/data-and-publications/national-greenhouse-gas-inventory-quarterly-update-march-2021   

• How does Australia’s GHG emissions compare to other nations? 
  • By volume: https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions 
  • Per capita: https://data.worldbank.org/indicator/EN.ATM.CO2E.PC?type=shaded&view=map  

Attachments: 

• New Scientist article 
• ECOS article link: https://www.csiro.au/Newsletters/ECOS/2022-04  
• Ensign article  
• Frank’s paper 

John Lane