Climate Change

Managing microclimates — a ‘third way’ to combat climate change

Effective microclimate management has the potential to reduce temperatures by 1.5-2 degrees Celsius

 
By Femke van Woesik, Frank van Steenbergen
Published: Thursday 02 March 2023
By carefully controlling local climates, communities can ease the impact of global climate change and create more resilient ecosystems. Photo: iStock

The release of the most recent report on climate change by the International Panel on Climate Change has sounded alarms in the global community, with headlines declaring a “code red for humanity”. The report warned that the world is on track to reach a 1.5 degrees Celsius increase in global temperatures within the next two decades, leading to more frequent and intense heatwaves and droughts. 

The response to this crisis involves two fundamental approaches: Mitigation and adaptation. Mitigation aims to reduce greenhouse gas emissions or increase the absorption of these gases. Adaptation involves adjusting to the effects of climate change to minimise harm, such as using crops better suited for extreme weather conditions. 

While both mitigation and adaptation are critical in addressing the global climate crisis, a third solution often goes overlooked: Managing microclimates. By carefully controlling local climates, communities can ease the impact of global climate change and create more resilient ecosystems.

Effective microclimate management has the potential to reduce temperatures by 1.5-2 degrees Celsius, serving as a buffer against the predicted rise in global temperatures over the next few decades. Moreover, local climate management is highly accessible. It can be implemented locally, ranging from entire watershed restoration efforts to placing a hedgerow on a farm to break the wind. 

Example of landscape restoration and water harvesting measures. These trenches accumulated moisture in the rainy season, which resulted in a local climate regulation effect in Tigray, Ethiopia. Source: Giulio Castelli

The idea of local climate management involves altering the energy balance of local climatic systems and, through that, the local climate. The fundamental principle behind this is energy conservation, which dictates that all incoming energy from the sun must be accounted for within the system. 

Here there are two options: The energy can contribute to evapotranspiration through the latent heat flux, or it can contribute to heating the air and soil through the sensible heat flux. 

How incoming solar energy is diverted into these two energy fluxes highly depends on landscape characteristics. In a desert environment with limited vegetation and low soil moisture levels, for instance, most energy will be utilised to heat the air and the soil, as only limited evapotranspiration is possible. 

Conversely, in a lush and well-watered area, the energy will be directed mainly towards evapotranspiration, resulting in a cooler local climate. This is because as more energy is directed towards the latent heat flux, less will be available for heating the air and soil. A reduction in sensible heat flux, thus, leads to a cooling effect on the local climate. The essence of microclimate management is to maximise the latent heat flux and minimise the sensible heat flux to achieve a cooler local climate. 

Visual representation of the diversion of energy fluxes for two landscapes: Desert (left) and highly vegetated area (right). Source: Wim Bastiaanssen

New research revealed the game-changing potential of local climate management in the fight against global warming. By implementing wind management, shading, mulching practices, water harvesting and regreening, we can alter the local energy balance, creating more favourable microclimatic conditions. 

A guidebook Managing the Local Climate provides a comprehensive tool to help achieve this goal. The key is to preserve soil moisture and maintain the water balance of a system through techniques such as stone bunds, trenches, check dams and more. 

Increased soil moisture leads to higher evapotranspiration, providing a cooling effect and reducing land surface temperature. For instance, studies in Ethiopia have shown that water harvesting measures reduced the temperature by 1.74°C. 

Increasing the amount of greenery in a system will also result in an uptake of latent heat fluxes, creating a cooling effect and replacing hot and dry air with moist and cooler air, as was found in the Medego watershed in Ethiopia. 

A study in Tanzania found that a higher tree canopy cover reduced local land surface temperatures and resulted in a more moderate microclimate. 

Controlling the local energy balance is a game-changer in the fight against global climate change. It allows people to take control of their immediate environment and create a buffer to protect against it.

Unlike other mitigation and adaptation methods, the impact of local climate management can easily be monitored and measured. With tools like remote sensing and sensors, we can quantify the variables that make up local climates and track changes over time and space. This lays the foundation for managing local climates on the ground and at the landscape level. By combining local knowledge with scientific methods, we can maximise our understanding of local climates, their fluctuations and transformations. 

A thermal image with a detail of 10 m x 10 m was acquired on 26 December 2021. This example from a midsummer day in Chile indicates more than 5 degrees Celsius variability due to different on-farm practices in an irrigated vineyard. Source: IrriWatch

This approach shows that the world's climate can be viewed as a patchwork of local climates ready to be improved through intentional, proactive and measurable action. This leads to cooler and better-buffered local climates that can withstand extreme events as we stitch together a mosaic of more vital climates farm by farm and landscape by landscape, all combined, contributing to 'making a new climate' as Judith Schwartz proposed in The Reindeer Chronicles.  This makes local climate management a crucial approach to address global climate change, as a third way next to mitigation and adaptation. 

Local climate management will result in more conducive conditions for farming, livestock keeping, pest and disease control, biodiversity, drought resilience, public health and human endeavour. With more inherent climate disruptions, there is an urgent need to unleash this hidden potential of local climate management as a proactive approach that harnesses the power of local action. 

Femke van Woesik works as programme manager at MetaMeta Research and is based in the Netherlands. Her work focuses on managing and improving local climates to create conducive and resilient conditions for both ecology and agriculture.

Frank van Steenbergen is a designer of puzzles, a writer of books and the founder of MetaMeta (www.metameta.nl), a company devoted to making a change in the management of our water resources.

Views expressed are the authors’ own and don’t necessarily reflect those of Down To Earth.

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