Rainbow water: rainfall, the water cycle, forests and trees

Rainbow water: rainfall, the water cycle, forests and trees

• 9.00 Welcome addresses (Prof. Joachim von Braun, ZEF)Block A New scientific insights // chaired by Grace Villamor (ZEF)9.15 Rainbow water, the missing colour. Meine van Noordwijk (ICRAF)9.35 Precipitation sheds, Patrick Keys9.55 What trees can tell us about climate variability and change. Aster Gebrekirstos 10.05 The new West Africa climate centre and this agenda. Manfred Denich& Paul Vlek

•Block B How does this relate to current climate policies and negotiations // chaired by Bruno Locatelli (CIFOR)10.30 Need for climate policy beyond mitigation and adaptation. Peter Minang10.40 Discussant comments. Bruno Verbist (European Forestry Institute)10.45 Discussion on relevance for new, more regional climate negotiations on land cover and water balance

Block C Priorities for linking this emerging science to policy action in climate policies and negotiations chaired by Henry Neufeldt (ICRAF)11.05-11.40 Brainstorm groups11.40-11.50 Plenary reporting11.50-12.00 Closing remarks

CRP6: Forests, Trees and Agroforestry: livelihoods, landscapes and

governance

Rainbow water, the missing colour Meine van Noordwijk (ICRAF)

• Grey water: added focus on pollution, cleansing and re-use water shortage relates to ‘quality’

Rainbow wa-ter closes the hydrological cycle, adds the concept of terrestrial evapotranspi-ration as ‘recycling’

•Rainbow =Recycled Atmospheric Inputs Now Bene-fitting our Water-supply

• Blue water: traditionally hydrology studies water flow in rivers, its use for irrigation, industrial & domestic uses water shortage & floods

• Green water: realized that water use in ‘upper watersheds’ is increased by forests & trees

The foresters’ view of the world

>>

The holistic forest+tree view of the world

Source: Global tree cover inside and outside forest, according to the Global Land Cover 2000 dataset, the FAO spatial data on farms versus forest, and the analysis by Zomer et al. (2009)

>

Forest and tree cover transitions: a unifying concept across CRP6

Temporal pattern

Spatial pattern

Institutional challenge

X-linkage of actions in landscape

Integrate Segregate

Farm fo-restry,

agrofo-rests

Natural forest

Fields, Forests & Parks

Open field agriculture

Plan

tatio

ns

Fiel

ds,fa

llow

, for

est m

osai

c

forest modification

agroforestation

re

- and

affo

rest

ation

defo

rest

ation

Sharing Sparing

Beyond variation in tree cover, we also need variation in ‘pattern’:

Solar radiation and Green-House Gas effect

Rainfall pattern&intensity

Temperature, humidity, windspeed, incoming radiation, potential eva-potranspiration at the level of plants or animals

Local tree cover: wind-breaks, shade trees

Water supply buffered by soil

Plant growth

Vegetation effects on rainfall triggering

Teleconnections of rainfall with sea sur-face temperature

Macro-

Meso-

Micro -climate

Macro-

climateMicro -

In the control simulation (FOREST), we consider a maximally forested world, while in the second

simulation (GRASS) all forests are replaced by grasslands.

oC

Coarsening of pattern: segregate

Ocean tempe-ratures El Nino, IOD

Rainfall in space & time

Land use: •plant production•pathways of water•timing of riverflow

River flow in space & time

Global climate

Upstream livelihoods

Downstream ,, ,,

Wanulcas

GenRiver, FlowPer

SpatRain, TempRain

GCM’s

RUPES/PRESA

CO2, CH4, N2O emissions

Ocean tempe-ratures El Nino, IOD

Rainfall in space & time

Land use: •plant production•pathways of water•timing of riverflow

River flow in space & time

Global climate

Upstream livelihoods

Downstream ,, ,,

Wanulcas

GenRiver, FlowPer

SpatRain, TempRain

GCM’s

RUPES/PRESA

CO2, CH4, N2O emissions

Cloud formation

Most studies have so far taken the global climate as ‘exogenous’ and

started hydrology with actual patterns of rainfall

• Some recent literature suggests that there is more to it…

Ellison D, Futter MN, Bishop K, 2011.On the forest cover–water yield debate: from demand- to supply-side thinking. Global Change Biology, doi: 10.1111/j.1365-2486.2011.02589.x

…the generally beneficial rela-tionship between forest cover and the intensity of the hydro-logic cycle.

…trees can redu-ce runoff at the small catchment scale.

Two schools of thought in the forest water debate: ‘supply-’ and the ‘demand-side’

Key points Ellison et al.• The ‘short cycle’ rainfall can contribute 1/5 – 2/3’s

of rainfall depending on location• About 1/3 of the ‘short cycle’ originates within the

(large) watershed, the rest is from outside• Increased tree water use contributes to ‘intensity

of hydrological cycle’ and may not have to be counted as ‘loss’ from a downstream perspective

Comments: • The same would hold for wetlands, irrigation agri-

culture, use of ‘sprinklers’ • Global increase in water use for irrigated areas

matches increased supply by ‘deforestation’

Bosilovich MG, Schubert SD (2002) Water vapor tracers as diagnostics of the regional hydro-logic cycle. Journal of Hydrometeorolo-gy, 3, 149–165.

Where does the precipi-table water in rainfall come from?

24-57% ‘short cycle’

origins

Ellison D, Futter MN, Bishop K, 2011.On the forest cover–water yield debate: from demand- to supply-side thinking. Global Change Biology, doi: 10.1111/j.1365-2486.2011.02589.x

37%

% of rainfall derived from ‘short cycle’ terrestrial origins(recalculated from Basilovich et al.)

68%58% 30%

40%41% 46% 22%

42%

1) Mackenzie river basin, 2) Mississippi river basin, 3) Amazon river basin, 4) West Afri-ca, 5) Baltics, 6) Tibet, 7) Siberia, 8) GAME (GEWEX Asian Monsoon Experiment) and 9) Huaihe river

basin.

Approximately a third comes

from ‘local’ sources

Terrestrial source areas (‘short cycle’) combine with oceanic (‘long cycle’) in a complex pattern of

‘teleconnections’Areas with high sea surface temperatures (SST) act as source areas of oceanic water vapour, areas with

high ET rates as terrestrial ones, but their link to rainfall in any area depends on dominant wind

patternsBeyond the ‘El Nino’ (ENSO) effect, the ‘Indian

Ocean Dipole’ (IOD) and Sea Surface Temperatures (SST’s) in many areas are now know to correlate

with rainfall

B: bimodal A: unimodal

C: unimodalStrong ENSO

response

Medium ENSO

response

No ENSO response

Bruijnzeel LA (2004) Hydrological functions of tropical forests: not seeing the soil for the trees? Agriculture, Ecosystems and Environment, 104, 185–22

Zeng, N., Neelin, J.D., Lau, K.M., Tucker, C.J., 1999. Enhancement of interdecadal climate variability in the Sahel by vegetation interaction. Science 286, 1537–1540

Fig. 1. Annual rainfall anomaly (vertical bars) over the West African Sahel (13–20◦N, 15◦W–20◦E) from 1950 to 1998: (A) observations

Zeng, N., Neelin, J.D., Lau, K.M., Tucker, C.J., 1999. Enhancement of interdecadal climate variability in the Sahel by vegetation interaction. Science 286, 1537–1540

Model with atmosphre & ocean interactions

(SST influences accounted for)

Adding land characteristics: (albedo,

soil moisture status)

Adding vegetation characteristics, with recovery time-lags

Bruijnzeel LA (2004) Hydrological functions of tropical forests:not seeing the soil for the trees? Agriculture, Ecosystems andEnvironment, 104, 185–22

Fig. 1. Geography of the regions where the dependence of precipitationP on distance x from the source of moisture was studied.

van der Ent RJ, Savenije HHG, Schaefli B, Steele ‐Dunne SC, 2010. Origin and fate of atmospheric moisture over continents. Water Resources Research 46, W09525,

E/P

Pfrom Et/P

Why India and China should invest in draining the Sudd and letting the water evaporate in Egypt in stead… and why

West Africa should be opposed to it

Deforesting Myanmar

will reduce rainfall in

China

South Africa’s concept of pay-ments for tree plantations that evaporate water at above-average rates, can not be transferred to E. Africa, where such evapotrans-piration is likely to return as rainfall.

Fig. 1. Geography of the regions where the dependence of precipitationP on distance x from the source of moisture was studied.

The transects that Makarieva & Gorshkov (2007) studied did not related to main mois-ture flux vector of van der Ent c.s.

Makarieva & Gorshkov pro-pose a ‘strong’ version of the

biotic effect where forests

generate wind & moisture

transport

Keys PW, van der Ent RJ, Gordon LJ, Hoff H, Nikoli R and Savenije HHG, 2012. Analyzing precipitationsheds to understand the vulnerability of rainfall dependent regions, Biogeosciences, 9, 733–746

Dryland agricultural areas where more than 50% of rainfall is derived from terrestrial recycling

Sahel

VOL + EL = PL ‘long cycle’ ‘short cycle’

Land + Atmosphere as hydro-logically open system

7 domains of hydrological influence of trees and forests:1.Enhanced EL means increased precipitation2.Triggering precipitation3.P partitioning over Q and Eintercept plus ΔS 4.ΔSL partitioning over Evarious and Q5.Q dynamics influenced by river & riparian zone6.Q use for irrigation7.Q use for domestic + in-dustrial use & recycling of waste water

Blue water

Brown water

Light Green water

Dark Green water

Rainfall

River flow

Water use

Recycled flows

Precipitable at-mospheric water

Oceans

Rainfall – Recycling feeWater ES fee (ES1)Water delivery feeWater cleaning fee (ES2)

~40%

~60%

Global climate change * geo-

graphy

Land use

Light green water

Blue water

Rainbow water

Dark green water

Grey/Brown water

ES1: buffering of waterflows rela-tive to incoming rainfall, securing quality of blue water flows

ES2: Cleaning of waster water to achieve quality standards for re-use

Patch-level water balance:P = Q + E + Sw

Regional water balance: Vi+1 – Vi = ΔSv = Qi = Pi – Ei + ΔSw,i

Rainfall

Water vapour in the air mass

Threshold for natural forest

forest edge

Increasing distance from the ocean – land interface

desert margin

At the ocean land-interface and at any distance from the

ocean, incoming water vapour flow (V) equals outgoing river flow Q

At patch level & annual scale:

P = E + Q

Evapo-transpiration

Rainfall

Water vapour in the air mass

Threshold for natural forest

forest edge

Increasing distance from the ocean – land interfaceIncreasing distance from the ocean – land interface

desert margin

At the ocean land-interface and at any distance from the

ocean, incoming water vapour flow (V) equals outgoing river flow Q

At patch level & annual scale:

P = E + Q

Evapo-transpiration

Sw

V

P E

Q

• Current international climate policy is built on the concept of ‘macro-climate’ change through CO2 and other greenhouse gas emissions

• Land use and land use change does contribute to emissions and hence is part of macro-climate change

• But, it also has a direct micro- and meso-climatic effect on temperature, humidity, windspeed – and even on rainfall

• Such mesoclimatic effects of tree cover work within an annual hydrological cycle, without the timelags of atmospheric policies

• They operate at regional rather than global scale and require new types of negotiations

Conclusions:1.The forest-climate discourse is overly carbonized2.Micro- and mesoclimatic influences of forests & trees have too long been ignored by scientists and remain undervalued in the climate policy arena3.Recent findings on rainbow water hydrology point to teleconnections of geopolitical importance

Mesoclimatic impacts of land cover change: research agenda

• Quantifying land cover change, focus on trees• Understanding drivers of tree cover change and ‘what

it takes’ to influence them• Multiplying change in land cover with ‘water recy-cling

activity factors’ in parallel to ‘GHG emission factors’ for GHG accounting

• Linking land cover change feedbacks into global/ regional climate change models (beyond statistical downscaling routines)

• Scenario studies on economy/environment interface• International/regional negotiations on change

pathways

V M A . X . . X .

. X .

X . X

X X X X X X

Geopolitics of climatic teleconnections, payments for ecosystem services and

pri-cing of water: four colours of water• Rainbow water is the source of all green, blue and

brown water flows• A large share of PES is linked to water delivery with

direct link between ‘goods’ and ‘services’• New insights into rainfall generation suggest

substantial (~40%) role for short cycle rain• Teleconnections on short cycle rain from green water

use suggest complex political relations• PES funds derived from blue water use need to

balance brown, green and rainbow water allocations

‘Mesoclimatic’ effects in the UNFCCC• The UNFCCC has been framed around the ‘macro-

climatic’ emission concept; hence mitigation implies reducing emissions and not reducing other anthropogenic change of climatic variables (incl. albedo, hydrological cycle links)

• The UNFCCC concept of ‘adaptation’ is about reducing human & ecosystem vulnerability in the face of anthropogenic climate change: it can (implicitly) include other pathways for anthro-pogenic climate change

http://wallpaperswide.com/rainbow_water-wallpapers.html Rainbow water clo-

ses the hydrological cycle, adds the con-

cept of terrestrial evapotranspiration

as ‘recycling’