Jdi white paper v11 20170102

White paper

IMPACTING THE CLIMATE THROUGH LAND RESTORATION How local changes can have a global impact

Title

Impacting the climate through land restoration

Subtitle

How local changes can have a global impact

Date

29 December 2016

Authors

Lucas Borst (SamSamWater) Merel Hoogmoed (SamSamWater) Sander de Haas (Justdiggit / SamSamWater) Taco Regensburg (Justdiggit) Fons Jaspers (Wageningen University) Bert Amesz (Justdiggit) Carlo Wesseling (Justdiggit)

Websites

www.justdiggit.org www.wur.nl www.samsamwater.com

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Table of context 1.

Preface ............................................................................................................................................................................................................4

2.

Introduction.................................................................................................................................................................................................5

3.

Problem definition ..................................................................................................................................................................................6

4.

5.

6.

3.1.

Negative feedback loop ...........................................................................................................................................................6

3.2.

Causes and consequences of land degradation .......................................................................................................7

3.3.

The value of ecosystems ..........................................................................................................................................................8

3.4.

Our approach in nine steps ................................................................................................................................................. 10

Steps in detail .......................................................................................................................................................................................... 11 4.1.

Step 1: Intervention .................................................................................................................................................................. 11

4.2.

Step 2: Water availability ....................................................................................................................................................... 12

4.3.

Step 3: Effects of water availability .................................................................................................................................. 13

4.4.

Step 4: Local benefits .............................................................................................................................................................. 14

4.5.

Step 5: Local climate effects ................................................................................................................................................ 14

4.6.

Step 6: More local precipitation ........................................................................................................................................ 15

4.7.

Step 7: Secondary climate effects.................................................................................................................................... 16

4.8.

Step 8: Regional climate effects ........................................................................................................................................ 16

4.9.

Step 9: Global climate impacts .......................................................................................................................................... 17

Where to start?........................................................................................................................................................................................ 18 5.1.

Status of degradation.............................................................................................................................................................. 18

5.2.

Physical properties .................................................................................................................................................................... 18

5.3.

Social factors ................................................................................................................................................................................. 18

5.4.

Impact on climate ..................................................................................................................................................................... 18

5.5.

Combining the key physical factors ............................................................................................................................... 18

Synthesis .....................................................................................................................................................................................................19 6.1.

Water harvesting as the key ................................................................................................................................................ 19

6.2.

Hydrologic corridor .................................................................................................................................................................. 19

6.3.

Global change ............................................................................................................................................................................. 19

References.............................................................................................................................................................................................................20

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1.

Preface

Justdiggit jumpstarts large scale landscape restoration projects in Africa.

Using water harvesting, agro-forestry and improved agriculture, we aim to increase local water availability and restore the vegetation cover in degraded areas. At larger scale, these landscape changes may alter local climatic conditions (evapotranspiration, temperature, cloud formation), which in turn can lead to positive regional climate impacts.

To achieve this, Justdiggit facilitates re-greening strategies to several large project areas (1,000’s of hectares each) within a so-called Hydrologic Corridor. The approach of Justdiggit and concept of the Hydrologic Corridor is described in brief in this video: @@@.

This white paper gives a more detailed description of the processes and theory behind our ambition to impact the regional climate by restoring degraded landscapes.

This document is meant for organizations, NGO’s and foundations who are looking for background information on re-greening and the effects on desertification, regional climate, river and groundwater regimes and possible spin-offs in social, economic, and natural resources. (Potential) partners, donors and fundraisers can find the scientific background in this document that supports the Justdiggit approach.

People are invited to share their knowledge with us. Please use what you find in this document. Both positive and negative feedback on our projects, methods and theoretical claims are more than welcome.

The report may grow in time, when more data is gathered and information is found. Everyone who wants to add to this document is encouraged to do so. For more information, please visit the website www.justdiggit.org or send your questions and contribution to info@justdiggit.org.

2.

Introduction

The Earth’s ecosystems are under escalating pressure due to rapid population increase and climate change. Results presented by UNCCD (2011) confirmed that 25% of Earth’s land mass is seriously degraded, climate change impacts crop yield by 15-50%, while desertification impacts biodiversity with 27,000 species disappearing every year. They stressed that by 2030 half of the world population (4 billion people) will be living in areas of high water stress, water scarcity might displace up to 700 million people and GDP in dry lands is 50% lower than in non-dry lands, impacting 1,5 billion people.

Justdiggit, a Dutch climate foundation, is implementing re-greening interventions over large areas with both local impact, regional spinoffs, and atmospheric effects. Justdiggit’s method is to restore degraded lands on a large scale using rainwater harvesting and other techniques to increase soil moisture and water availability. This leads to an increase of vegetation in these degraded lands.

Greening has a positive effect since vegetation retains fertile soils, slows down runoff, improves infiltration and cools surface temperatures. If done on a large enough scale these landscape changes also affect local climatic conditions (evapotranspiration, temperature, cloud formation), which in turn have a positive effect on regional climate.

To achieve these large-scale effects Justdiggit works on a so called ‘Hydrologic Corridor’: a new approach to rehabilitate ecosystems at strategic chosen project locations. These project locations are strategically chosen to maximize their impact on the whole region of the hydrologic corridor. The scientific theories behind the concept of the hydrologic corridor and its impact on the regional climate are described in this document.

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3.

Problem definition

At present, there are many locations where rainwater flows away rapidly through surface runoff into streams and rivers, transporting fertile soils, leaving the land dry and bare. The philosophy of regreening itself is straightforward. By retaining rainwater, vegetation will have a chance to grow which creates a healthier local ecosystem. This in turn has positive effects on the local climate, which in turn affects regional rainfall. Increased rainfall allows for more vegetation to emerge, and a positive feedback loop occurs. The first step of rainwater harvesting breaks the negative vicious circle and creates a better environmental situation for ecosystems and people and wildlife. This principle is shown schematically in Figure 1.

Figure 1

Schematic representation of the effects of water harvesting and re-greening.

Around the world there are many initiatives working to re-green Earth. Thus, an enormous amount of knowledge and data is available in reports, documentaries, and scientific articles. The report you’re reading aims at combining available information to substantiate the Justdiggit theory of change and identify positive and negative arguments on this approach.

The blocks in the figure above will be elaborated in this document. At the end of this report an overview of the literature used is given. In the text, references are indicated with brackets ([reference]] which refer to the number in the reference list.

3.1.

Negative feedback loop

For centuries people used natural resources to build a living. Since the number of people was relatively small, the people lived in harmony with the ecosystems they inhabited, resulting in enough water, food, and materials without depleting the source. During the twentieth century the world population grew rapidly (UN, 2015). In turn, an increasing number of people needs food, water, and commodities, which put ever more stress on the utilized ecosystems. Due to this higher demand leads to overexploitation of many ecosystems, which are unable to restore and recuperate. This puts these systems in a perpetual circle with negative feedbacks, illustrated in Figure 2.

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Overexplationion of remaining resources by unsustainable land use (e.g. overgrazing, deforestation, groundwater depletion)

Less resources available for vegetation growth, foodproduction / water harvesting / materials

Due absence of protection by vegetation, soil erosion by wind and water leads to creation of gullies and wastelands and results in lowering groundwater tables

Decline in biomass, decrease of biodiversity, decrease in water stored in soil, decline of soil fertility, increase of soil erosion

Figure 2. a simplified representation of the negative feedback loop that leads to land degradation At present, the world population is still growing and the consumption per capita is rising, increasing stress on land, soils, and available resources. With respect to land degradation, the key feature is that land shortage in the region has led to widespread agricultural use of areas vulnerable for land degradation (FAO, 1994).

3.2.

Causes and consequences of land degradation

Why is ecosystem restoration needed? The productivity from agriculture has a monetary value. But natural systems, biodiversity, biomass, water infiltrating the soils are often not valued in the same way, but are “Natural Capital” (Mazzotta, 2000). It seems that non-investing in natural resources leads to destruction and desertification of previous fertile lands.

By degradation lands will become barren, available water and production of foods diminishes and water and food scarcity will occur. This will have several direct and indirect effects: • In healthy ecosystems water is stored during rainy seasons in soils, naturally delaying the runoff to rivers and feeding downstream wetlands, aquifers (underground water bearing layers) and rivers. The whole catchment benefits the entire year from natural storage during the wet season. Barren lands are less able to hold water, leading to rapid discharge of rainfall. These systems are degenerated and fertile soils eroded, water is not stored during rainy seasons.

Downstream wetlands, aquifers and aquifers will dry, rising the pressure on the decreased amounts of water left.

• Since less water is available during extended dry seasons and downstream rivers bearing less water, water stress has downstream effects on ecosystems and social economic stability.

• Less water leads to less vegetation. Trees and plants provide the vital service of photosynthesis by taking CO2 from the air and providing oxygen, reducing greenhouse effects.

• People living in these barren regions are expected to migrate to other regions as climate refugees (Walter, 2005;UNHCR, 2016). The UN already is developing plans to cope with climate refugees.

These negative effects of soil erosion already show the consequences of poor land management. It implies that healthy ecosystems have large benefits. The negative feedback loop can only be broken by drastic changes in land management. Measures should be taken to retain water, so it will be available longer into the dry season, and ecosystems can be restored. The process of ecosystem restoration 7