Rainbow water: rainfall, the water cycle, forests and trees
Rainbow water: rainfall, the water cycle, forests and trees9.00 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 Gebrekirstos10.05 The new West Africa climate centre and this agenda. Manfred Denich& PaulVlekBlock B How does this relate to current climate policies and negotiations // chairedby 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 landcover and water balanceBlock C Priorities for linking this emerging science to policy action in climatepolicies 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 •Rainbow =Recycled Atmospheric Inputs Now Bene- missing colour fitting our Water-supply Meine van Noordwijk (ICRAF)• Blue water: traditionally hydrology Rainbow wa- studies water flow in rivers, its use for ter closes the irrigation, industrial & domestic uses hydrological water shortage & floods cycle, adds• Grey water: added focus on pollution, the concept cleansing and re-use water shortage of terrestrial relates to ‘quality’ evapotranspi-• Green water: realized that water use in ration as ‘upper watersheds’ is increased by ‘recycling’ forests & trees
> >The holistic forest+tree the world world The foresters’ view of view of theSource: Global tree cover inside and outside forest, according to the Global Land Cover 2000dataset, 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 X-linkage ofTemporal Spatial Institutional actions in pattern pattern challenge landscape
Beyond variation in tree cover, we also need variation in n Op‘pattern’: tio en sta fie re- and afforestation re ld a r of o gri cul ag Fields,fallow, forest mosaic tur eFarm fo- Plantations restry, Fields, agrofo- Forests rests & Parks deforestation f ore st m est odi for Sharing fica ral Sparing tion atu Integrate N Segregate
Solar radiation and Green-House Gas effect Vegetation effects on rainfall triggering Macro- Teleconnections of rainfall with sea sur- face temperatureRainfall pattern&intensity Meso- Local tree cover: wind- breaks, shade treesTemperature, humidity,windspeed, incoming Micro - Plant growthradiation, potential eva-potranspiration at the level climate Water supplyof plants or animals buffered by soil
o CIn the control simulation (FOREST), we considera maximally forested world, while in the second simulation (GRASS) all forests are replaced by grasslands.
Global CO2, CH4, N2Oclimate GCM’s Ocean tempe- emissions El Nino, IOD ratures Rainfall in space & time SpatRain, TempRain Land use: Wanulcas •plant production •pathways of water •timing of riverflowGenRiver, FlowPer River flow in Upstream livelihoods space & time RUPES/PRESA Downstream ,, ,,
Global CO2, CH4, N2Oclimate GCM’s Ocean tempe- emissions El Nino, IOD ratures Rainfall in Cloud formation space & time SpatRain, TempRain Land use: Wanulcas •plant production •pathways of water •timing of riverflowGenRiver, FlowPer River flow in Upstream livelihoods space & time RUPES/PRESA Downstream ,, ,,
Most studies have so far taken the global climate as ‘exogenous’ andstarted hydrology with actual patterns of rainfall• Some recent literature suggests that there is more to it…
Two schools of thought in the forest water debate: ‘supply-’ and the ‘demand-side’ …the generally beneficial rela- …trees can redu- tionship between forest cover ce runoff at the and the intensity of the hydro- small catchment logic cycle. scale.Ellison D, Futter MN, Bishop K, 2011.On the forest cover–water yield debate: from demand- to supply-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’
Wheredoesthe Bosilovich MG,precipi- Schubert SD (2002) Water vapor tracerstable as diagnostics ofwater in the regional hydro- 24-57%rainfall logic cycle. Journal ‘short cycle’ of Hydrometeorolo-come origins gy, 3, 149–165.from?
% of rainfall derived from ‘short cycle’ Ellison D, Futter MN, Bishop K, 2011.On terrestrial origins(recalculated from Basilovich et al.) the forest cover–water yield debate: from demand- to supply- 37% 58% 30% 68% side thinking. Global Change Biology, doi: 10.1111/j.1365-2486.2 011.02589.xApproximatelya third comes from ‘local’ 42% sources 40% 41% 46% 22% 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.
Terrestrial source areas (‘short cycle’) combine with oceanic (‘long cycle’) in a complex pattern of ‘teleconnections’Areas with high sea surface temperatures (SST) actas 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 patterns Beyond the ‘El Nino’ (ENSO) effect, the ‘IndianOcean Dipole’ (IOD) and Sea Surface Temperatures (SST’s) in many areas are now know to correlate with rainfall
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 Bruijnzeel LA (2004) Hydrological functions of tropical forests: not seeing the soil for the trees? Agriculture, Ecosystems and Environment, 104, Zeng, N., Neelin, J.D., Lau, 185–22 K.M., Tucker, C.J., 1999. Enhancement of interdecadal climate variability in the Sahel by vegetation interaction. Science 286, 1537–1540
Bruijnzeel LA (2004) Hydrologicalfunctions of tropical forests:not seeing the soil for the trees?Agriculture, Ecosystems andEnvironment, 104, 185–22 Model with atmosphre & ocean interactions (SST influences accounted for) Adding land characteristics: (albedo, soil moisture status) Adding vegetation characteristics, with recovery time-lags 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.Geography ofthe regionswhere thedependence ofprecipitationP on distance xfrom the source ofmoisture wasstudied.
Pfrom Et/Pvan der Ent RJ, SavenijeHHG, Schaefli B, Steele-Dunne SC, 2010. Originand fate of atmosphericmoisture overcontinents. WaterResources Research 46, E/PW09525,
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 Myanmarwill reduce rainfall in China
South Africa’sconcept of pay-ments for treeplantations thatevaporate waterat above-averagerates, can not betransferred to E.Africa, wheresuch evapotrans-piration is likely toreturn as rainfall.
The transectsthat Makarieva& Gorshkov(2007) studieddid not relatedto main mois-ture flux vectorof van der Entc.s.Fig. 1.Geography ofthe regionswhere thedependence ofprecipitationP on distance xfrom the source ofmoisture wasstudied.
Makarieva &Gorshkov pro-pose a ‘strong’ version of the biotic effect where forestsgenerate wind & moisture transport
Dryland agricultural areas where more than 50% of rainfall is derived from terrestrial recycling SahelKeys PW, van der Ent RJ, Gordon LJ, Hoff H, Nikoli R and Savenije HHG,2012. Analyzing precipitationsheds to understand the vulnerability ofrainfall dependent regions, Biogeosciences, 9, 733–746
Land + Atmosphere as hydro- logically open system 7 domains of hydrological VOL + EL = PL influence of trees and forests: ‘long cycle’ ‘short cycle’ •Enhanced EL means increased precipitation •Triggering precipitation •P partitioning over Q and Dark Green Eintercept plus ΔS water •ΔSL partitioning over Evarious Blue and Q water •Q dynamics influenced by Light river & riparian zone Green water •Q use for irrigation Brown •Q use for domestic + in- water dustrial use & recycling of waste water
Rainbow water Precipitable at- ~40% ES1: buffering of waterflows rela- mospheric water tive to incoming Dark green Land rainfall, securing quality of blue water use ~60% Rainfall water flows Rainfall – Recycling fee Water ES fee (ES1) Blue River Water delivery fee water Water cleaning fee (ES2) flow Light greenGlobal climate Water waterchange * geo- use graphy ES2: Cleaning of waster water to Recycled achieve quality Grey/Brown water flows standards for re- Oceans use
Regional water balance:Vi+1 – Vi = ΔSv = Qi = Pi – Ei + ΔSw,i At the ocean land-interface ∆VWater and at any distance from the P Evapour in ocean, incoming waterthe air mass vapour flow (V) equals outgoing river flow Q ∆Sw desertRainfall margin Threshold for natural forest forest edge Q Increasing distance from the ocean – land interfaceEvapo-transpiration Patch-level water rive r balance: toCo ntr. P = Q + E + ∆Sw e ti v w At patch level & m ula flo annual scale:Cu river 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:2.The forest-climate discourse is overlycarbonized3.Micro- and mesoclimatic influences offorests & trees have too long beenignored by scientists and remainundervalued in the climate policy arena4.Recent findings on rainbow waterhydrology point to teleconnections ofgeopolitical importance
Mesoclimatic impacts of land cover change: research agenda V M A• Quantifying land cover change, focus on trees . X .• Understanding drivers of tree cover change and . X . ‘what it takes’ to influence them• Multiplying change in land cover with ‘water recy- . X . cling activity factors’ in parallel to ‘GHG emission factors’ for GHG accounting• Linking land cover change feedbacks into global/ X . X regional climate change models (beyond statistical downscaling routines) X X X• Scenario studies on economy/environment interface• International/regional negotiations on change X X X pathways
Geopolitics of climatic teleconnections, payments for ecosystem services andpri-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’