The United Nations Intergovernmental Panel on Climate Change (IPPC) has published a new report on Climate change, Impacts, Adaptation & Vulnerability [1]
It describes the proven links between climate change and biodiversity loss, migration, risks to urban and rural activities, health, food, water, and energy.
The negative impacts of climate change are mounting much faster than scientists predicted less than a decade ago [2]
Approximately 3.3 to 3.6 billion people living in contexts that are highly vulnerable to climate change, so it is essential that all available steps are taken to address climate change. The report is clear that this must include changes to diet.
The report is a summary of previously published science and it was good to see that papers supporting plant based diets were referenced, eg, Reducing food’s environmental impacts through producers and consumers [3]
This paper, by Joseph Poore includes some striking remarks about what plant based diets can achieve:
- Today’s food supply chain creates ~13.7 billion metric tons of carbon dioxide equivalents (CO2eq), 26% of anthropogenic GHG emissions
- Today, and probably into the future, dietary change can deliver environmental benefits on a scale not achievable by producers.
- Moving from current diets to a diet that excludes animal products has transformative potential:
- – Reducing food’s land use by 3.1 billion hectares (a 76% reduction)
– including a 19% reduction in arable land
– food’s GHG emissions by 6.6 billion metric tons of CO2eq (a 49% reduction)
– acidification by 50%
– eutrophication by 49%
– scarcity-weighted freshwater withdrawals by 19%
The impacts of animal products can markedly exceed those of vegetable substitutes, to such a degree that meat, aquaculture, eggs, and dairy use ~83% of the world’s farmland and contribute 56 to 58% of food’s different emissions, despite providing only 37% of our protein and 18% of our calories
Section 5.12.6 of the IPCC report, “Changing Dietary Patterns” focused more on the cultural and social aspects of plant based diets, and emphasised how difficult it is to make behavioural changes in the area of diet.
It observes that studies simply educating people about the negative health and environmental/climate outcomes of meat consumption have been found to have very little impact, and that plant foods are strongly shaped by social-cultural norms.
Certainly, there are social and cultural norms to consider when looking to move to plant-based diets. But for me, what changed everything was understanding the extent of the impending climate and biodiversity crisis, and the immediate and effective way that plant-based diets can help to counter it.
It was interesting to read of a study on the “Order of meals at the counter and distance between options affect student cafeteria vegetarian sales”, but the science was enough for me, and the order of meals at the counter did not really affect my decision.
A “randomized controlled field experiments using a vegetarian lunch” was discussed in the report, but I would suggest that education is also a major part of the answer. The findings of scientists such as Poore need to be reproduced in a format that is accessible and convincing to the average reader, and produces an emotional and reasoned response. However, as highlighted in the report, we need to take on board that “simply educating people about the negative outcomes” is not enough.
As there is so much that is positive about a plant based life this should not be insurmountable! How can we convert these findings into feelings for our world and action on our palates and plates?
This is the second of three reports. The first report, Climate Change 2021: The Physical Science Basis was published last year [4]
Climate change is a huge subject. The 3675 pages of the latest report do not make quick or easy reading, but have been helpfully condensed into a readable Summary for Policymakers Headline Statements (5 minute read) [5]
Here are some quotes from the Summary Headline Statements B-D with relevance to food production and the CO2 emissions of unsustainable livestock farming …
B2 Vulnerability of ecosystems and people to climate change … driven by …unsustainable ocean and land use …
Approximately 3.3 to 3.6 billion people live in contexts that are highly vulnerable to climate change (high confidence) …
B3 Global warming, reaching 1.5°C in the near-term, would cause unavoidable increases in multiple climate hazards and present multiple risks to ecosystems and humans (very high confidence)
B6. If global warming transiently exceeds 1.5°C in the coming decades or later (overshoot), then many human and natural systems will face additional severe risks, compared to remaining below 1.5°C
D5 Importantly climate resilient development prospects are increasingly limited if current greenhouse gas emissions do not rapidly decline, especially if 1.5°C global warming is exceeded in the near term (high confidence).
My comments on the first report published in August 2021
References
[1] https://www.ipcc.ch/report/sixth-assessment-report-working-group-ii
[2] https://www.nature.com/articles/d41586-022-00585-7
[3] https://josephpoore.com
[4] https://www.ipcc.ch/report/sixth-assessment-report-working-group-i
[5] https://www.ipcc.ch/report/ar6/wg2/resources/spm-headline-statements
