Climate

The Climate and Sustainable Food pages will present over the next 12 months a series of short articles on topics in climate and sustainability under four headings: 1) climate and crops – the effects of weather and climate on crops and grass; 2) lessons from past events, trends and trajectories; 3) status of the food system now; 4) the need for repair and regeneration.

Climate and Sustainable Food production

1 Climate and crops

The weather in any year affects production through the biology of crops and grass and the timing and type of field operations. Over a much longer time scale, and within the broad ranges set by landscape and soil, climate determines which crops can grow and when in the year they can be sown and harvested.

1.1 The biological responses of crops and grass to weather-factors will form the base of the series. Coverage will include solar radiation through the seasons and years; temperature ranges for survival and growth; effects of rainfall on soil water status, evaporation, flooding, runoff and leaching; hail and storm; and the importance of matching plant type with the likely weather in any year. In each case, links will be shown between weather, survival of crops and grass and their yield. Summary articles will show how weather-factors together determine which crops and grass species can grow here, their sensitivities to possible future climate, and opportunities for new crops and livestock.

1.2 Field operations are designed to interact with the biological responses of plants to achieve a specified yield and quality of product. Operations include soil cultivation, sowing, fertilisation, pest control, harvest; and control of grazing period, and cutting and drying grass for hay and silage. In most years the weather disrupts one or more of these operations, but in severe-weather years such as 2012, a crop may be lost.

2 Lessons from the past

The present position of agriculture and the food system depends not only on today’s weather, seed and markets (among other factors) but on past trajectories and disruptive events that have taken agriculture along certain routes, while closing off other possibilities. 

2.1 Trends and trajectories can last for decades in agriculture. Examples include shift from sufficiency in the early 1800s to dependency a century later;  the crops versus grass conflict from 1850 to 2020; the decline of oats and the rise of barley for alcohol and feed; the loss of nitrogen-fixing legumes and reliance on mineral nitrogen; intensification 1960-1990; and recent trends even farther from self-sufficiency towards dependence on imports.

2.2 Events – cataclysms and bad-weather years. Events include major perturbations such as the Laki volcanic eruption in the late 1700s as well as short term ‘extreme’ weather such as the heat and drought of 1976 and the 2012 rain and floods. Each case will consider the effect on production and the rate at which the systems reacted and recovered. Events can cast a long shadow: a run of bad weather in the early 1880s caused a shift of crops to grass and an ensuing trajectory that is still felt today.

3 Status of the Food System

The interaction between biological factors, past influences and external forcers determine the type of agriculture that we have now. The result is a diverse mix of staple grain crops, vegetables, grass for grazing and hay, lowland livestock and upland rough grazing. The mix sounds ideal. Yet agriculture and food security have been decoupled.

3.1 Climate and the distribution of crops and grass – “the great northern divide’. The combination of weather factors in lowland Scotland creates the potential for some of the highest yields in the UK, but only up to certain latitudes (and altitudes). Farther north (and west), due to the cold and wet, annual crops coexist with and then give way to permanent grazing. The mix provides some resilience, but crop varieties and grass swards have been de-diversified and soils are degrading in many areas. Agriculture could, but does not, produce enough of the staple grains to ensure food security. 

3.2 The food supply chain is long and complex. External demands determine much of what is grown in fields. Despite the high productivity and potential for more, many observers agree that the food system is in disarray. Here the narrative looks at important aspects that need to be fixed, including the balance between food, alcohol and livestock feed, reliance on imports, long supply chains and the poor price paid to producers. 

4 Climate will change – let’s be ready

The main questions are about how to prepare for whatever happens, even if we do not know precisely what that will be. It may be more frequent occasions of extreme weather, a marked shift in the mean or a cataclysmic event. 

4.1. Repair and regeneration. Agriculture, forestry and related land use need to repair and regenerate soil, reduce erosion, rebalance energy/matter cycles, and restore habitat and biodiversity. Articles will consider practical measures to achieve these aims. 

4.2 Moving the food system to a sustainable trajectory. The present serious imbalances in the food system need to be corrected, including the reliance on imports and the dominance of long supply chains. The system as a whole, not only production, has to be reorganised to ensure a country can always guarantee its food security.

Sources and justification

The Living Field, being primarily an outreach project, does not tend to cite scientific papers and reports in its usual articles and posts. For this series, a selection of relevant papers and reports will be listed to support each article, ideally ones that are ‘open access’ or available online for anyone to view.  

sustainable croplands