Sustainability (with Data)

I’m reading Not the End of the World by Hannah Ritchie, a data scientist and communicator. The book leverages data analysis to strike an optimistic tone about “how we can be the first generation to build a sustainable planet”, the subtitle of the book. The influence of Hans Rosling can be seen in her work – while there are things that are getting worse for the planet and humankind, many things are also getting better. Each chapter comes with things we should be working on, and things we shouldn’t overly stress about. Ritchie doesn’t sugarcoat the data, but she interprets it in context.

 

She begins with the provocative idea that “the world has never been sustainable” making use of the United Nations definition of sustainability as “meeting the needs of the present without compromising the ability of future generations to meet their own needs”. Humans have been changing the world and its flora and fauna for thousands of years, be it through expanding agriculture or hunting larger beasts to extinction. But there have been many improvements in human health and longevity and improving standards of living. On the other hand, we’ve been gobbling up resources and it becomes questionable what we’re doing to future generations. Ritchie tackles seven problems: air pollution, climate change with temperature rise, deforestation, the food network, loss of biodiversity, plastics in the ocean, and overfishing.

 

I’m lucky to live in an area where the air quality is relatively good. When I was in graduate school in the ‘90s, folks who had lived in that same area in the ‘70s would tell me horror stories of the smog. The Clean Air Act in the U.S., implemented in 1970 and signed by Nixon (who also created the EPA, who apparently didn’t care about environmental issues, but who cared what voters and the public thought). Ritchie, based in the U.K., provides plots showing the peak of air pollution from the ‘50s to the ‘70s and how the emission of various gases and black carbon have plummeted approaching 18^th century levels. Even China has passed its air pollution peak, and that wasn’t just because they hosted the Olympics. Ritchie discusses the need to provide access to clean cooking fuels, remove sulfur from fossil fuels, and end winter crop-burning (something I didn’t know about).

 

Climate change is tricky – you’d assume that everyone should just switch to “renewable” energy as soon as possible, but that’s not so easy because greenhouse gas emissions has multiple sources. There are trade-offs in each of these energy-hungry sectors. Three-quarters of our transport emissions come from driving on roads. I was surprised that shipping and aviation contributed only ten percent each. Electric vehicles help but there are tradeoffs; better still would be redesigning our cities and living spaces to reduce the use of cars. What caught my attention was food. Producing beef is an order of magnitude worse than chicken; plant-based proteins are even better. We also need to reduce overconsumption and wastage. I also learned that eating “local” or “organic” aren’t necessarily better. It depends. Ritchie provides both the data and the analysis.

 

Growing up in the tropics, I appreciated Ritchie’s nuanced discussion on deforestation and the protection of biodiversity. Yes, humans have cut down a third of the world’s forest mainly to make room for agriculture. But you can start to see the recovery at least in some “richer” countries. I remember the controversies surrounding palm oil some years ago. Ritchie tackles the health arguments and myths, but she also discusses the productivity of palm oil per hectare compared to almost any other common oil crops. Palm oil is more sparing in terms of land-use. The issue of beef comes up again because it’s particularly greedy for land-use where we’re growing crops mainly to feed the cows. Lamb actually takes a little more land use, but has lower emissions than beef. It was however heartening to see Ritchie’s data that the world may have passed peak agricultural land use and looks like it might also be reaching peak fertilizer use. Humans have been able to increase crop yields to feed the planet through a variety of strategies. Norman Borlaug gets several mentions.

 

On the topic of biodiversity, I learned from Ritchie’s charts that in terms of global biomass measured by carbon, plants are 82%, bacteria are 13%, fungi are 2%, and animals are 0.4%. Within the animal category, humans are 2.5%, livestock are 4%, and the largest shares go to fish at 29% and arthropods at 42%. Are we humans causing the Earth’s sixth mass extinction? Depends on how you look at it. Overall, biodiversity is decreasing but there’s a lot of variation. Some species are showing increases or recoveries; others continue down the path to extinction. And ecology is complex. You think you can do this one thing to affect this one thing, and then find out that there are many unanticipated knock-on effects. Ritchie also provides graphs showing the leveling of tonnage in wild seafood catch compared to aquaculture; and there’s also a bar chart on the carbon footprint for different kinds of fish. Apparently sardines have a very low carbon footprint. (Lobster and flounder are very high.) Tuna is a little better than chicken, and salmon does even better in this regard.

 

What I liked about Ritchie’s book is that it made me stop and think about the complex web of sustainability and ecosystems. I might even make some gradual lifestyle changes in what I eat, although as it is I rarely eat beef or lamb. For someone living in the U.S., my consumption of energy is relatively low and I buy very little outside of food. I won’t give up driving just yet (although my mileage per year is probably on the lower side). I could start composting and do a better job sorting my trash and not wasting stuff. I thought Ritchie did an effective job using the data to marshal arguments, and it’s something I could improve in my teaching to help students do so better. Ritchie’s book is a very accessible read and I recommend it.