Since there are no currently active contests, we have switched Climate CoLab to read-only mode.
Learn more at
Skip navigation
Share via:


Polycultures of woody plant species combined with animals, managed along keylines produce healthy food and capture 3-10 times more carbon.



Natural ecosystems combining trees, shrubs and large herbivores show the highest soil organic matter contents and the highest C-sequestration rates. Grass-fed cattle properly managed overcompensates its greenhouse gas emissions and agroforestry is estimated to sequester 3-10 times the carbon of arable land. The global sequestration potential of afforestation is 205 gt C, but this number ignores arable land as potential planting area. If we swap regularly tilled arable land for production systems with tree crops, shrubs and animals, we can produce food in a way that is storm-proof, resists erosion, stores water and is drought-proof, prevents flooding events, retains nutrients and builds up vast amounts of humus to sequester C from the atmosphere. These effects are further enhanced by implementing management structures in a keyline pattern, which can multiply the nutrient and water retention.

Food produced in such systems is far healthier than food mainly based on cereals. In our annuals-based diet, many people suffer from obesity and allergies, whereas chestnuts, nuts, fruits and meat were the diet of humans for most of their existence on earth and kept them healthy. Such crops are also more resilient to drought and do not suffer from deficiencies in human input like the dropout of tillage and sowing in crises - all of which are to become more likely with climate change. Therefor, tree crops or agroforestry polycultures can easily feed our food industry with carbohydrates, proteins and oils, but are always available for subsistence economy in case of a food system collapse. Such systems can be upscaled, but also downscaled when necessary. They can be implemented world wide and democratically, enhancing rural communities and the livelihoods of small farmers and especially women.

In summary, the large scale implementation of complex agroforestry is the most efficient and quick way to boost C-sequestration, food security and good livelihoods.

Is this proposal for a practice or a project?


What actions do you propose?

set up powerful grant programmes for planting tree crops for staple foods in polycultures and keyline patterns

set up breeding programmes for staple food trees and shrubs like e.g. in temperate climate chestnuts or saskatoon berries.

abolish grants for purely annual plant based agriculture

launch campaigns to advertise for eating healthier with tree crops

set up best-practice farms in every region, eg.
-https://newforestfarm.usin Wisconsin
- Brandenburg, Germany
- Switzerland

make legal changes to allow nutrient cycling with dry toilets and proper hygenization

implement tax deduction possibilities for people who subscribe to community supported agricultures based on perennial crops

make the implementation of complex agroforestry polycultures a worldwide priority by declaring a "UN decade of planting tree crops" and make it mandatory for UN member states to implement grant and legal policies accordingly

Who will take these actions?

The proposal author can advise on complex agroforestry and runs a planning agency. He is involved in several organisations that work for more implementation of agroforestry in Europe. A leading role in a quick implementation of the described practices should be taken by the UN. EU and USA governments should start an initiative for a UN resolution to start the decade of planting tree crops. Specialist support can be obtained from the World Agroforestry Organisationhttp://worldagroforestry.orgthe European Agroforestry Federationhttp://www.eurafagroforestry.euGerman DeFAFhttp://defaf.deor from pioneers such as the proposal author

Where will these actions be taken?

actions must take place on a global scale, but specifically in regions of intensive agriculture. Europe and the US may play an important role in demanding worldwide policy changes. They are also important places because they are to a large extent responsible for the intensification of agriculture worldwide, creating a high demand for animal fodder on the world market. A change in the agriculture and food system of these countries will therefore have a huge impact on agriculture world wide. The EU and the USA should make their own agriculture sustainable again by implementing complex agroforestry polycultures and become more self-suffient in food production, so that their impact on the world market will no longer promote degrading practices.

In addition, specify the country or countries where these actions will be taken.

United States

Country 2


Country 3


Country 4

United Kingdom

Country 5



What impact will these actions have on greenhouse gas emissions and/or adapting to climate change?

C-sequestration rates of arable land multiply by 3-10

Landscapes can be cooled, rain probability can be enhanced

The proposal will enhance food security and crisis resilience

What are other key benefits?

see above


What are the proposal’s projected costs?

Not implementing the proposal will cost us a fortune and our future.


The proposal will have an immediate impact once it is implemented. Declaring a UN decade of planting tree crops or UN decade of agroforestry should be done within the next year, so it could be 2020-2030.  In the short term, replacing annual plant based agriculture with complex agroforestry polycultures, will have an effect on roughness element density of landscapes when trees start growing on arable land. Droughts which became more common in recent years will not have such an impact on crops from in 5 years on. Then, the tree crops will begin to bear significant amounts of fruit, and will start to replace annual crops. In 15 years, tree crops reach their longterm high productivity phase. Landscapes will benefit from sugnificant cooling, more moisture and the food system will be much more stable. The carbon sequestration will start having an impact on global climate, but the overshoot effect will cause a further rise in temperature. In 50-100 years, the global tree planting of the 2020ies will be regarded as one of the key factors besides C-emission reduction that caused the temperature rise to stay below 1.5°C.

About the author(s)

The author Philipp Gerhardt lives in Germany. He studied forestry science in Germany, Sweden and Austria and graduated in 2009. Since 2004 he did research in the field of sustainable food production in forests and gardens. In 2015 he started to advise and plan agroforestry operations in Germany. Besides his work as an agroforestry planner, he works on a PhD thesis at Vienna University of Applied Life Sciences.

Related Proposals


Bastin, Jean-Francois, et al. 2019. The global tree restoration potential. Science. 2019, Bd. 365, 6448, S. 76-79.

Cardinael, R., et al. 2017. Increased soil organic carbon stocks under agroforestry: A survey of six different sites in France. Agriculture, Ecosystems and Environment. 2017, 236, S. 243-255.

Crews, T.E., et al. 2016. Going where no grains have gone before: From early to mid-succession. Agriculute, Ecosystems and Environment. 2016, 223, S. 223–238.

Gruner, R.L., Power, D. 2017. Mimicking Natural Ecosystems to Develop Sustainable Supply Chains: A Theory of Socio-ecological Intergradation. Journal of Cleaner Production. 2017, 149, S. 251-264.

Keesstra, Saskia, et al. 2018. The superior effect of nature based solutions in land management for enhancing ecosystem services. Science of the Total Environment. 2018, 610, S. 997–1009.

Oehria, J., et al. 2017. Biodiversity promotes primary productivity and growing season lengthening at the landscape scale. PNAS. 2017, 114(38).

Oelbermann, M., Voroney, R.P. und Gordon, A.M. 2004. Carbon sequestration in tropical and temperate agroforestry systems: A review with examples from Costa Rica and southern Canada. Agriculture, Ecosystems and Environment. 2004, 104, S. 359-377.

Pandey, D.N. 2002. Carbon sequestration in agroforestry systems. Climate Policy. 2002, 2 (4), S. 367-377.

Pardon, P., et al. 2017. Trees increase soil organic carbon and nutrient availability in temperate agroforestry systems. Agriculture, Ecosystems and Environment. 2017, 247, S. 98-111.

Rhodes, C.J. 2012. Feeding and healing the world through regenerative agriculture and permaculture. Science Progress. 2012, 9582), S. 101-201.

Rockström, J., et al. 2017. Sustainable intensification of agriculture for human prosperity and global sustainability. Ambio. 2017, 46, S. 4–17.

Ryan, Justin A., et al. 2015. Modelling the Potential of Integrated Vegetation Bands (IVB) to Retain Stormwater Runoff on Steep Hillslopes of Southeast Queensland, Australia. Land. 4, 2015, S. 711-736.

Ryan, Justin G., McAlpine, Clive A. und Ludwig, John A. 2010. Integrated vegetation designs for enhancing water retention and recycling in agroecosystems. Landscape Ecology. 25, 2010, S. 1277–1288.

Schwarzer, Stefan. 2019. The potental of carbon sequestraton in the soil. Foresight Brief - Early Warning, Emerging Issues and Futures. 2019, 13, S. 1-12.

Siddique, I., et al. 2007. Changes in soil chemistry associated with the establishment of forest gardens on eroded, acidified grassland soils in Sri Lanka. Biology and Fertility of Soils. 2007, 44, S. 163-170.

Teague, W.R. und Barnes, M. 2017. Grazing management that regenerates ecosystem function and grazingland livelihoods. African Journal of Range & Forage Science. 2017, 34.

Torralba, M., et al. 2016. Do European agroforestry systems enhance biodiversity and ecosystem services? A Meta-Analysis. Agriculture, Ecosystems and Environment. 2016, 230, S. 150-161.