Today I'm going to be digging into all things related to agriculture and land use and the impact this is having on both climate change and biodiversity. The rain forests of Brazil used to be famous for their role in cleaning the world's air but due to deforestation and the repurposing of land for cattle farming and other commercial purposes, Brazil's land mass is now a net-emitter (even before you add in emissions from fossil fuels). In fact there are only a handful of countries in the World that are now playing the role as net "carbon sinks".
I've prepared a model below which incorporates data from Sentinel 2 the European Space Agency satellites that survey the Earth's landmass. The 3 most important colors on the map are:
Pink - agricultural land
Red - built-up areas (such as cities, where most people live)
Green - what remains of our forests
While the red built-up areas are responsible for a large portion of emissions related to sectors such as construction (e.g. from steel and cement) you will note that from a land-use perspective, the footprint of humankind is made up largely of the pink agricultural regions. In the UK we only use about 5% of the land to accommodate the humans but then take up another 50-70% (depending on how you interpret the data) to feed ourselves and to feed the animals that we use to feed ourselves.
Biodiversity impact
In the chart above, I've included an extract from the Biodiversity Intactness Index for each country, published by the PREDICTS team at the National History Museum (NHM). I met a few interesting characters at COP26 last week but none more interesting than Prof. Andy Purvis who leads the PREDICTS team. He has invited me down to the NHM to look at all the biological specimens they have collected throughout history which they use to show how various species have died out in various locations through time. The indices were all pretty much 100% intact up until the 17th/18th century when the agricultural practices start becoming more industrialized. This lifted a lot of people from the food poverty line and created food surpluses in many regions but had a devastating effect on biodiversity. The UK has lost around 60% of its land species. Prof. Purvis pointed out that Surinam which hasn't yet adopted industrialized farming is one of the few remaining places in the world where the biodiversity is still largely intact. You can see this for yourself from the data above.
Life Cycle Analysis (LCA)
Scientists have been modeling emissions for many decades and have developed a framework known as Life Cycle Analysis (LCA) for doing this. As the name suggests, rather than focussing only on the emissions coming directly from a product or process, LCA attempts to track emissions from cradle-to-grave. So for a car, the lifecycle would include extraction and processing of raw materials, the manufacturing of components, assembly, the use phase and then finally the end-of-life phase when the car is scrapped.
Below are the results of my LCA for the meat industry. At 10 billions tonnes, the fully-load lifecycle emissions from the cattle industry including the effects of deforestation make up 25% of the global carbon budget (across all sectors). Luckily we still get some carbon sink benefits from the remaining forests so the net emissions from land use are something like 20% of the total across all sectors.
You can see from the above that the LCA has allowed me to break down the input emissions for cattle herding including items such as fertilizer and feed. This is how we get to the true cradle-to-grave numbers.
This is a very complex topic and I'm realizing that you can't understand land use until you understand soil where most of the land carbon is stored. But my high-level diagnosis of the problem is that we take up too much land and need to shrink back our footprint in agriculture and other commercial land use. Land use for animals is particularly problematic because we also need extra cropland to feed the animals some animals (cows and sheep) release a lot of methane which is many times more potent than CO2 as a GHG.
Supply-side innovation - Vertical farming
And how do we squeeze the world's farms onto a smaller footprint while feeding the growing population of humans? The answer: vertical farming.
Demand-side innovations: Carbon Added Tax (C.A.T.)
And how do we convince consumers to switch from red meat to a plant-based alternative? The answer: Carbon Added Tax.
The above is slightly tongue-in-cheek idea and the last thing I want to do is unleash a whole new branch of bureaucracy on businesses to fill out C.A.T. forms alongside their V.A.T. forms. However, we have seen with other industries such as tobacco that government intervention is necessary in certain areas to educate and change the behaviors of consumers and I'd be interested to hear people's ideas of how to do this with food.
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