With the rise of civilizations, humans began having significant impacts on bodies of water and the water cycle.  The early “hydraulic civilizations” appeared along major rivers (Nile, Tigris-Euphrates, Indus, Yellow River and others), changed watercourses and built canals for agriculture and transportation.  As populations and cities expanded, demand for food led to soil depletion while the built environment created growing areas of impermeable surfaces. Disruption of water cycles has reached a peak since the industrial revolution, with large areas of land covered with impermeable surfaces, and rainwater and waste rapidly shuttled away from land into the oceans. [Kravčik 2007: 42 ff.]

Eco-restoration requires a shift in thinking about water management and fortunately there are many successful water restoration projects under way, along with a strong theoretical basis to guide them.  Water management is the key to cooling the biosphere, regenerating photosynthesis and drawing down carbon on billions of acres. Included in this section is a brief discussion of wetlands, which will be expanded in the next Compendium release.

Several eco-restoration examples are included here, and many were explored at our 2015 Restoring Water Cycles to Reverse Global Warming Conference at Tufts University – all speaker videos are available online. https://bio4climate.org/program-tufts-2015/. 

Overview

Healthy Soils Australia, Walter Jehne 2015. Walter Jehne is a microbiologist, soil and climate scientist who has spent the past several years teaching and promoting the use of nature’s tools to address destruction of land and water cycles, and educating on methods important in addressing global warming.  The text below represents excerpts (condensed and edited) from the paper, “Restoring Regional Rainfalls: Background Brief for Outcomes, Australia Forum on Vegetation-Rainfall Relationships”:

Contrary to the dominant assumptions that global warming is due to elevated atmospheric carbon concentrations,

1. Systemic climate changes such as aridification began in the 1970s well before CO2 levels or its temperature effects increased abnormally.
2. Water-based processes govern most climate effects and over 95% of the earth’s heat dynamics for billions of years, including some 80% of the natural greenhouse effect.
3. These hydrological heat dynamics have been ignored or deemed “secondary feedbacks” to the CO2 greenhouse effect because water is assumed to be a dominant determinant of our climate, and humans could not possibly have altered these global cycles to cause the anthropogenic climate changes
4. The hydrological processes are highly complex and difficult to model, and were therefore excluded in IPCC (Intergovernmental Panel on Climate Change) assumptions and models, whereas the minor CO2 component of the greenhouse effect is more readily modelled, and provides a simple marketable explanation of its “cause.”
5. Because of these IPCC assumptions, policy and response options have largely ignored the dominant hydrological determinants on climate, the effects of land management, and impacts these changes may have on climate, water and bio-system stability.

Yet we have greatly altered the earth’s natural hydrology and thus heat dynamics by:

1. Clearing over 75% (6.3 billion hectares or 15.75 billion acres) of the earth’s primary forest, greatly altering the land’s albedo and heat reflectance as well as transpiration and latent heat fluxes that cooled vast regions.
2. Oxidizing and eroding organic matter from some 10 billion hectares of soils thereby reducing the ability of landscapes to infiltrate, retain and supply water to sustain cooling transpiration and latent heat fluxes and the drawdown of carbon from the air by plants via photosynthesis.
3. Exposing vast areas of such degraded, cropped and bare soils to erosion which has dispersed 3 billion tonnes of additional dust aerosols into the air where it nucleates warming humid hazes that retain heat in the biosphere.
4. Heating bare exposed soils to greatly increase their re-radiation of heat which massively increases greenhouse warming effects.
5. Increasing the absorption of solar radiation by humid haze micro-droplets [resulting in] global dimming (while in the liquid phase), as well as the absorption of re-radiated heat (while in the gaseous phase) to warm the lower atmosphere via the water vapour greenhouse effect.
6. Reducing regional rainfalls often by up to 30% due to the increase in persistent haze micro-droplets which are too small to coalesce into raindrops and precipitate by themselves.
7. Increasing surface humidity due to the persistent humid hazes, thus lowering evaporation rates by up to 10% and reducing latent heat fluxes which transfer heat out of the biosphere into space.
8. Reducing the production of the biological precipitation nuclei from forests that would help coalesce the humid haze micro-droplets to form dense clouds with high albedos that reflect 33% of solar radiation out to space, thereby regulating global temperatures.
9. Preventing the nucleation of haze and cloud droplets into raindrops which lowers rainfalls and the level and longevity of transpiration, photosynthesis and cooling latent heat fluxes.
10. Impairing the night-time escape of re-radiated heat to space via natural “radiation windows” due to the impaired nucleation and precipitation of such “blocking” humid micro-drop hazes.
11. Increasing sustained high pressures above the cleared, bare heated soils that prevents the inflow of cool moist air from oceans, its precipitation and the associated cooling heat fluxes.
12. Extending such high pressure over vast regions and periods to accentuate the aridification of bio-systems which readily collapse to deserts with further human land degradation. [Healthy Soils Australia 2015: 1-2]

Given this reality we need solutions that go beyond just reducing future CO2 emissions but also:

1. Cool regions and the climate so as to offset dangerous warming and its feedback effects.
2. Draw down carbon back into its safe soil sinks so as to reduce its greenhouse effect.
3. Restore the resilience of agro-ecosystems and communities to the extremes and secure their essential water, food and bio-material needs via just, safe low carbon futures. [Healthy Soils Australia 2015: 8]
4. Regenerate natural hydrological processes by land management which captures water in soils, wetlands, aquifers and biomass
5. Maintain healthy biodiverse soils to Restore microbial drivers that govern these cooling hydrological processes by emitting condensation nuclei that lead to rainfall.
6. Support the biological sequestration of carbon from the air into stable soil humates and glomalin to enhance the water held in the soil reservoirs that sustain the cooling latent heat fluxes.
7. Support the production of microbial precipitation nuclei that coalesce the warming humid hazes into dense high albedo clouds that cool regions and generate critical cooling rainfalls.
8. Promote the nucleation and enhancement of rainfall in key regions to maintain the latent heat fluxes, green vegetated habitats and the radiation windows that enhance nighttime cooling effects.

Only by regenerating our forests, soils and landscapes can we now restore the hydrological cooling processes that helped govern the natural heat dynamics and buffered climate of the blue planet. Such regeneration is now our only option to offset the dangerous climate feedbacks resulting from the warming induced by our landscape degradation and its associated abnormal rise in CO2 levels.  

Fortunately viable practical options exist to enable us to do and directly benefit from this, at grass roots community level: tree by tree, hectare by hectare, region by region. While we face a global emergency and must all take responsibility for it, it can only be addressed locally via practical action on the ground by communities driven by their own self interest in securing a safe climate and future.

The good news is we can still avoid the pending extremes and collapse provided we focus on direct local action urgently to regenerate the health of each square metre of soil and each forest and tree. We have the abundant degraded land, sunshine, CO2, waste biomass and nutrients to do it with. To grow more green areas; by regenerating our soils, forests, rangelands and even re-greening deserts.

We can do this if we enhance the infiltration, retention and availability of each raindrop in our soils so that the regenerated ‘in soil reservoirs’ sustain healthy green growth over larger areas for longer. This will happen naturally, synergistically, as plant growth enhances the structure of the soil by increasing its carbon content which in turn aids its water holding capacity and nutrient dynamics.

Just as nature did over the past 420 million years in colonizing and greening the earth’s land surface, these same processes are now our only option to regenerate our soils, forests and landscape and re-secure our safe climate and future. [Healthy Soils Australia 2015: 7-11]

Water Article Summaries

Ellison 2017.  “Trees, forests and water: Cool insights for a hot world” may be one of the few articles in the mainstream literature relating to climate that puts hydrological cooling effects before carbon in importance for addressing global warming, although dynamics of water and carbon are closely intertwined.

Forests and trees must be recognized as prime regulators within the water, energy and carbon cycles. If these functions are ignored, planners will be unable to assess, adapt to or mitigate the impacts of changing land cover and climate. Our call to action targets a reversal of paradigms, from a carbon-centric model to one that treats the hydrologic and climate-cooling effects of trees and forests as the first order of priority. For reasons of sustainability, carbon storage must remain a secondary, though valuable, by-product. [Ellison 2017: 51]

This paper is discussed further under Forests.

Evans, Griggs 2015.  Carol Evans is a fisheries biologist and Jon Griggs is a rancher in northeastern Nevada. They have worked together over twenty-five years to restore overgrazed lands to health through planned grazing of cattle, which also brings water, trout, beavers and biodiversity to the riparian areas of Maggie and Susie Creeks. In the driest state in the U.S., with less than ten inches of rain a year, they now have perennial streams and wet meadows after five years of the worst drought in memory.

Susie Creek, ca. 1989 (left) and 2015 (right) after five years of drought.  Elko, Nevada

Kravčík 2007.  Michal Kravčík and co-authors are Slovakian hydrologists who have developed what they call a new water paradigm for managing water cycles, floods and drought.  

In a healthy water cycle, while some rain enters streams and rivers directly and is carried off to sea, most rain water is absorbed by the soils in situ, where it lands. The rain gives life to the soil and sets many biological processes in motion, where it is essential for stable soil carbon storage and cooling the biosphere. This includes evapotranspiration from plants which returns water as vapor to the atmosphere where the water condenses and falls as rain. The cycle then begins anew.  Kravčík et al. call this the “small water cycle”  (i.e., local water cycle) where most water goes through its cycles in a regional area or smaller.  The “large water cycle” is the exchange of water between oceans and land, and “above land water circulates at the same time in many small water cycles which are subsidized with water from the large [continental or global] water cycle.” [Kravčík 2007: 16]

Civilizations disturb healthy water cycles and accelerate the runoff from land by creating impermeable surfaces (including degraded farmlands and rangelands), and preventing water from remaining in place to sink into soils or to forcing it to run off the land, causing floods and often carrying valuable topsoil with it.  Furthermore, water systems have been engineered to move water away from its source to the oceans.  Water, with its growing use as a means to dispose of farming, industrial and human wastes, is even seen as a nuisance.  As a result, less water returns to continents from the oceans than is lost from continents to oceans, which leads to desiccation of soils, severe drought, wildfires, desertification, and a measure of sea-level rise.  There is a growing understanding that these phenomena, often attributed to climate change, may in fact also be a function of disrupted water cycles.

Restored urban land, Kosice. November 2005 (left), September 2006 (right).

Heat from the sun drives these earthly water cycles.  Small water cycles are local, circulating water within a relatively small area. Latent heat causes water to evaporate; heat is absorbed in the process of evaporating water and does not result in an increase in local temperature. We thus do not experience latent heat as an increase in temperature.  However, when there is less water available for evaporation, less solar energy is transformed into latent heat and more solar energy is transformed into sensible heat, heat you can feel as increased temperature.  This is the heat that we are increasingly experiencing as global warming.

A great deal of heat is moved from the surface of the earth to the upper atmosphere by evaporation and transpiration of water by plants, contributing to significant cooling of the biosphere – to illustrate it takes 540 calories to turn 1 gram of water to vapor; by comparison it takes only 80 calories to melt 1 gram of ice.

Draining of land, that is, runoff and floods, can be reversed through comprehensive conservation of rainwater which maintains the sponge-like absorption capacity of soils and maintains many aspects of soil health, resilience, biodiversity and productivity. Renewal of small water cycles over land can temper extreme weather events and ensure a growth in water reserves by eliminating heat islands and problematic distribution of atmospheric moisture.

Nobre 2010. Antonio Nobre is an Amazon scientist who has studied the biotic pump (see also Makarieva), and tells how he was once told by an indigenous wise man,

“Doesn’t the white man know that, if he destroys the forest, there will be no more rain? And that if there’s no more rain, there will be nothing to drink, or to eat?” I heard that . . . [ and thought], “Oh, my! I’ve been studying this for 20 years, with a super computer; dozens, thousands of scientists, and we are starting to get to this conclusion, which he already knows!” A critical point is the Yanomami have never deforested. How could they know the rain would end? This bugged me and I was befuddled. How could he know that?

Some months later, I met him at another event and said, “Davi, how did you know that if the forest was destroyed, there’d be no more rain?” He replied: “The spirit of the forest told us.”

The equatorial region, in general, and the Amazon specifically, is extremely important for the world’s climate. It’s a powerful engine for evaporation.  From a satellite viewpoint, atmospheric water flow can look like a geyser, which is underground water heated by magma transferred into the atmosphere.  There are no geysers in the Amazon but trees play the same role.  They, like geysers, transfer an enormous amount of water from the ground into the atmosphere.  Nobre continues:

There are 600 billion trees in the Amazon forest, 600 billion geysers. That is done with an extraordinary sophistication. They don’t need the heat of magma. They use sunlight to do this process. On a typical sunny day in the Amazon a large tree manages to transpire 1,000 liters of water. If we take all of the Amazon, which is a very large area, and add up all the water that is released by transpiration, “the sweat of the forest,” an incredible amount of water is evaporated into the atmosphere: 20 billion metric tons of water per day. . . . This river of vapor that comes up from the forest and goes into the atmosphere is greater than the Amazon River.”

The Amazon River itself is the largest river on Earth, it carries one fifth of all the fresh water, it releases 17 billion metric tons of water a day into the Atlantic Ocean, smaller than “the river in the sky.”  To evaporate the 20 billion tons of water released by trees it would take 50,000 of the largest hydroelectric plant in the world, Itaipus, which generates 14 GW of electricity, 30% of Brazil’s power.  The Amazon does this with no technology, at no cost.

Schwartz 2016.  Judith Schwartz once again travels the world to collect stories of lands restored, of lives revived, this time to glean insight from restorers of water.  She demonstrates that many of our assumptions about managing water are derived from engineering, not biology.  When biology is the focus of the water and rainfall question the problem is redefined,  and clarified.  Solutions that had been invisible become apparent, and provide the opportunity for far more effective responses – even in some of the driest places on earth.  Floods and droughts become manageable, even preventable entirely.  Two of the innovators mentioned in Water in Plain Sight, Michal Kravčík and Rajendra Singh, spoke at Biodiversity for a Livable Climate’s 2015 Restoring Water Cycles conference, as did Judy.

Singh 2007.   Rajendra Singh, the “Water Man of India,” tells the story of how he helped over 1,000 villages restore water and abundance through the use of ancient, low-technology land management. Providing water for people, farms and animals, such efforts countered the ill effects of industrialization and reversed flight to the cities.  Says Singh:

I am neither a scientist, nor a professional water engineer nor a climate change expert. I am a small constructive worker of Gandhi and I mobilize the civil society and the community for action on natural resources management and conservation for rural uplift in India. Here I am recording the impact of the above work on the ecology of 6,500 square km area in Alwar district from 1985‐2007. Since 1985, 8,600 small water harvesting talabs [a form of check dam] in 1,068 villages of Alwar district covering 6,500 square km area have been built. This has resulted in the shallow aquifer recharge in groundwater bringing up the water table from about 100‐120 meters depth to 3‐13 meters at present. The area under single cropping increased from 11 per cent to 70 per cent out of which area under double cropping increased from 3 per cent to 50 per cent bringing prosperity to the farmers. The forest cover, which used to be around 7 per cent increased to 40 per cent through agro‐forestry and social forestry, providing sufficient fuel wood and sequestering carbon from atmosphere [Singh 2007: 5].

A dramatic example of how large restoration efforts are built from small, local efforts.  In the ten years since this paper, Tarun Bhagat Sangh has continued to expand its work.