By Pete Smith, Camille Parmesan & Mark Maslin
There are options for addressing climate change and biodiversity loss together – so called nature-based solutions – which are solutions to societal challenges that involve working with nature.
A landmark report (1) authored by the world’s most senior climate and biodiversity scientists argues that the world will have to tackle the climate crisis and the extinction crisis simultaneously, or not at all. Scientists from the Intergovernmental Panel and Climate Change (IPCC) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) collaborated for the first time to deliver this stark warning.
The reason that the two crises need to be tackled together is because the land and oceans already absorb about half of the greenhouse gases that we emit, with animals, plants, fungi and microbes playing a critical role in maintaining this carbon sink. If we lose the functions provided by biodiversity, we will lose at least some of this natural sink. We must also tackle climate change, which will exacerbate this biodiversity loss (1). But the way that we address climate change also has to support biodiversity – climate solutions that damage biodiversity will ultimately fail.
Luckily, there are options for addressing climate change and biodiversity loss together – so called nature-based solutions – which are solutions to societal challenges that involve working with nature (2). If implemented well, these can enhance biodiversity, help ecosystems to store more carbon or reduce emissions of greenhouse gases, make ecosystems more resilient to climate change and contribute to the delivery of the UN sustainable development goals.
Here are five actions that can make a difference:
- Protect high carbon and high biodiversity (pristine) ecosystems on land and in the ocean. Everyone is familiar with the need to protect our tropical rainforests but there are other pristine habitats we need to protect. For example, mangrove swamps and seagrass meadows. Despite occupying less than 1% of the global area, mangroves store the equivalent of 22 billion tonnes of carbon dioxide (3), around two thirds of total annual emissions of carbon dioxide from fossil fuels. They are also a hotspot for biodiversity, acting as a home and feeding ground for a range of species of fish, insects, reptiles, birds and mammals (4).
- Restore degraded high carbon and high biodiversity ecosystems. For example, peatlands store vast quantities of carbon. Peatlands store twice as much carbon as all the world’s forests. In the UK peatlands store the equivalent of over 10 million tonnes of carbon dioxide – and are home to some of our most precious plant and animal species (5). The top 15 cm of a peatland store more carbon below ground than tropical rainforest does above ground – but over 80% of the UK’s peatlands are degraded. A single hectare of degraded peatland can emit in excess of 30 tonnes of carbon dioxide each year – equivalent to the yearly emissions of more than seven family cars.
Protecting ecosystems can prevent carbon being released into the atmosphere. Restoring them where they’ve been damaged can suck carbon dioxide from the air and guarantee shelter for rare wildlife. Diverse natural systems also bounce back better (1) from climate extremes than do species-poor, highly degraded systems, and will keep helping biodiversity and people even as Earth continues to warm.
- Manage agricultural land and fisheries. We can’t protect all of the world’s land and oceans as we need to use some of it to feed us and produce timber. But we can manage our land and oceans more effectively. Industrial agriculture and fisheries are extremely damaging to biodiversity and contribute significantly to climate change – the food system is responsible for about a third of all greenhouse gas emissions (6). Regenerative agriculture, agroecology and sustainable fishing practices are all nature-based solutions allowing us to manage our food production more sustainably. Globally, animal agriculture is a major contributor to global biodiversity loss (7) and a driver of climate change – contributing nearly 60% of all emissions from the food system (8).
- Create new woodlands and forests– but with care! We have already cut down three trillion trees, half the trees on Earth, so we know our planet can support a lot more trees. Creation of new woodlands and forests where they once were can drawdown atmospheric carbon dioxide and provide diverse habitats for a range of species, but great care must be taken to plant the right mix of trees in the right place. Monoculture, non-native production forestry can be a poor biodiversity habitat – whereas the mix of native tree species can be great for biodiversity and store more carbon in the long run (1). The marine equivalent is seagrass planting.
- Shift to more plant-based diets. Reducing demand for meat and dairy, through dietary change and waste reduction, would not only significantly reduce greenhouse gas emissions – which itself benefits biodiversity through limiting climate change – it would also reduce pressure for deforestation and on other natural habitats, and free land and resources for the wider use of nature-based solutions. Meat, especially highly processed meat, has been linked to: high blood pressure, heart disease, chronic obstructive pulmonary disease, and bowel and stomach cancer. So plant-based diets are healthier and will ultimately reduce healthcare costs around the world.
For every good way of implementing a solution, there are numerous bad ways! To ensure that the measures we take to address climate change are truly nature-based solutions, four guiding principles have been proposed to provide sustainable benefits to society (2):
- Nature-based solutions are not a substitute for the rapid phase out of fossil fuels
- Nature-based solutions involve a wide range of ecosystems on land and in the sea, not just forests
- Nature-based solutions must be implemented with the full engagement and consent of Indigenous Peoples and local communities in a way that respects their cultural and ecological rights
- Nature-based solutions should be explicitly designed to provide measurable benefits for biodiversity.
By using the five principles of protect, restore, manage, create and shift while following the four guidelines, we can design robust and resilient nature-based solutions that address the twin crises of climate change and biodiversity loss, while sustaining nature and people together, now and into the future (2).
References:
(1) Pörtner, H.O., Scholes, R.J., Agard, J., Archer, E., Arneth, A., Bai, X., Barnes, D., Burrows, M., Chan, L., Cheung, W.L., Diamond, S., Donatti, C., Duarte, C., Eisenhauer, N., Foden, W., Gasalla, M., Handa, C., Hickler, T., Hoegh-Guldberg, O., Ichii, K., Jacob, U., Insarov, G., Kiessling, W., Leadley, P., Leemans, R., Levin, L., Lim, M., Maharaj, S., Managi, S., Marquet, P., McElwee, P., Midgley, G., Oberdorff, T., Obura, D., Osman, E., Pandit, R., Pascual, U., Pires, A. P. F., Popp, A., Reyes-García, V., Sankaran, M., Settele, J., Shin, Y. J., Sintayehu, D. W., Smith, P., Steiner, N., Strassburg, B., Sukumar, R., Trisos, C., Val, A.L., Wu, J., Aldrian, E., Parmesan, C., Pichs-Madruga, R., Roberts, D.C., Rogers, A.D., Díaz, S., Fischer, M., Hashimoto, S., Lavorel, S., Wu, N., Ngo, H.T. 2021. Scientific outcome of the IPBES-IPCC co-sponsored workshop on biodiversity and climate change. IPBES secretariat, Bonn, Germany, https://zenodo.org/record/4930848#.YMthT2hKjIU
(2) Seddon N, Smith A, Smith P, Key I, Chausson A, Girardin C, et al. 2020. Getting the message right on nature-based solutions to climate change. Global Change Biology Available from: https://doi.org/10.1111/gcb.15513
(3) Sanderman, J., Hengl, T., Fiske, G., Solvik, K., Adame, M. F., Benson, L., Bukoski, J. J., Carnell, P., Cifuentes-Jara, M., Donato, D., Duncan, C., Eid, E. M., Ermgassen, P. zu, Lewis, C. J. E., Macreadie, P. I., Glass, L., Gress, S., Jardine, S. L., Jones, T. G., … Landis, E. (2018). A global map of mangrove forest soil carbon at 30m spatial resolution. Environmental Research Letters, 13(5), 055002. https://doi.org/10.1088/1748-9326/aabe1c
(4) UNEP WCMC (2020) 5 facts about mangroves and why we must protect them. https://www.unep-wcmc.org/news/5-facts-about-mangroves-and-why-we-must-protect-them
(5) WWF-UK and RSPB (2021) The role of nature in a UK NDC. https://www.rspb.org.uk/globalassets/downloads/Nature_Based_Solutions_NDC_ReportV2.pdf
(6) Crippa, M., Solazzo, E., Guizzardi, D. et al. (2021) Food systems are responsible for a third of global anthropogenic GHG emissions. Nat Food 2, 198–209. https://doi.org/10.1038/s43016-021-00225-9
(7) Crist E, Mora C, Engelman R. 2017. The interaction of human population, food production, and biodiversity protection. Science 356, 260–4. Available from: http://dx.doi.org/10.1126/science.aal2011
(8) Poore J, Nemecek T. 2018. Reducing food’s environmental impacts through producers and consumers. Science, 360, 987-992. doi: 10.1126/science.aaq0216
Pete Smith is a Professor of Soils and Global Change at the University of Aberdeen.
Camille Parmesan is a Professor in the School of Biological and Marine Sciences at the University of Plymouth.
Mark Maslin is a Professor of Earth System Science at University College London.
Disclaimer: The ideas expressed in this article reflect the author’s views and not necessarily the views of The Big Q.
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