Medical News
By Michael Le Page
We need use land to help soak up carbon emissionsNunes Ribeiro/EyeEm/Getty
A special UN report on climate change and land use warns that a massive expansion of bioenergy would reduce biodiversity, cause desertification and water scarcity, and push up food prices. That’s bad news because just about every plan for limiting warming to 2C or less involves using bioenergy on a massive scale to remove carbon dioxide from the atmosphere.
On the plus side, the report says that improving our diets – such as eating less meat – would help reduce carbon emissions as well as improving public health.
Here’s what you need to know about the latest report from the Intergovernmental Panel on Climate Change (IPCC):
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Remind me, what is the IPCC again?
It’s the UN body that assesses the evidence related to climate change. Almost all the work is done voluntarily by scientists.
Why is the IPCC looking at how we use land?
Because land is both a major source of greenhouse gas emissions and also soaks up a lot of the extra carbon dioxide we are pumping into the atmosphere. A quarter of all greenhouse emissions so far are a result of the ways we exploit land, and the global food system produces a third of all emissions. We currently use 12 per cent of land for growing crops and exploit 70 per cent, often in ways that damage it by causing, say, soil erosion. We need to use it in sustainable ways that soak up carbon dioxide rather than releasing it.
This report is about more than just climate change, then?
Yes. The full title is the “special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems”. You’re welcome!
And it says we don’t have enough land to expand for a big expansion in bioenergy?
Environmentalists and anti-poverty campaigners have been saying for years that relying on bioenergy to remove CO2 from the atmosphere would be a disaster. Now it’s official. “At the deployment scale of several gigatonnes of CO2 per year, this increased demand for land conversion could lead to adverse side effects for adaptation, desertification, land degradation and food security,” says the report. We’d need to remove 40 Gt CO2 per year to just to balance out current emissions.
Hold on, how does bioenergy help remove CO2?
The idea is to grow plants such as fast-growing grasses, burn them in power plants to produce electricity, and to remove and store the CO2 emitted rather than letting it go out the chimneys. But if we don’t slash fossil fuel emissions, it would require stupendous amounts of land to remove enough CO2 to limit warming to 1.5°C – five times the area of India is one estimate.
What about food security?
Food prices are projected to rise as global warming affects food production more and more. Because bioenergy competes with food production, it will push up food prices even further, hurting the poorest people the most.
Does this mean we can’t use land to help capture carbon?
Far from it. Recently the land has been soaking up far more CO2 than it is releasing. Deforestation released 6 Gt CO2 between 2008 and 2017, but plant growth soaked up 12 Gt CO2. There are many ways we can make it soak up even more, such as restoring natural forests.
It’s not all doom and gloom, then?
Many ways of reducing emissions and adapting to a warmer world “can also combat desertification and land degradation and enhance food security,” the report says. Those that do not increase demand for land “can contribute to eradicating poverty and eliminating hunger while promoting good health… and life on land.”
Can you give examples?
If people cook with electricity from wind or solar instead of burning firewood, it helps prevent desertification, improves health and reduces emissions all at once. The report also says “genetic improvement” of plants and livestock will help. Many will read that as meaning genetic engineering.
And another option is eating less meat?
The report does not say so in as many words but that’s certainly the implication. “Balanced diets, featuring plant-based foods, such as those based on coarse grains, legumes, fruits and vegetables, nuts and seeds, and animal-sourced food produced in resilient, sustainable and low-GHG emission systems, present major opportunities,” it says. Dietary changes could reduce emissions by up to 8 GtCO2 per year by 2050.
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