Jatropha curcas: from Global Hype to Local Solution. Trabucco A., Achten W., Aerts R., Van Orshoven J., Mathijs E., Muys B.

Transcription

1 Jatropha curcas: from Global Hype to Local Solution Trabucco A., Achten W., Aerts R., Van Orshoven J., Mathijs E., Muys B.

2 Jatropha: Basic Facts Jatropha Potentials: Small tree (5-7 meters), originary from Central America. Non-food crop, unlike most of biofuels. Biofuel easily extractable from seeds with mechanic press. Adapted to semiarid conditions and suited for marginal land. The Mith: Adapted to very arid conditions (as low as 300 mm of annual precipitation) Very high seed productivity (as high as 20,000 kg of dry seeds per ha per year)

3 Jatropha: The Hype The Building of a Hype: Concern about fossil fuels price, reserves and sustainability. Sudden interest for Jatropha, as optimal biofuel solution. Jatropha remains still a mysterious plant with agro-climatic properties still unclear. Over optimistic expectations for productivity and suitability in arid conditions. Large and rapid investements from public and private sectors on Jatropha plantations based on disappointing expectations.

4 Jatropha: Productivity Assessment Lack of Productivity Assesment: Traditional methods to evaluate land suitability and crop productivity use agroclimatic knowledge still not available for Jatropha. Implementation of a Novel Method to Assess Jatropha Productivity: Given the impellent need of agroclimatic knowledge to assist Jatropha economic interests, we implemented a novel method relating biophysical factors to seed productivity through fitness metrics (Maximum Entropy approach, Philips et al 2006). Significant accuracy evaluation from seed yield measurements (r 2 = 0.62) and positive expert evaluation.

5 Jatropha Seed Productivity Map Jatropha follows largely a pan tropical distribution, favoring areas with a dry season. Suitable areas are observed in warm temperate climates with enough rainfall, a drought period and no frost risk.

6 Jatropha Productivity 500 liters of biofuels are extracted from 2000 kg of dry seeds. Average oil consumptions per person per year: liters as a global average. 100 liters in most developing countries. Average productivity for Köppen climate classes Köppen Classification Average Productivity (kg dry seeds ha 1 yr 1 ) TROPICAL Fully Humid 1150 With strong monsoon and short dry season 2200 With strong dry season > 60 mm 2300 TEMPERATE Subtropical desert with average temperature > 18 C 750 At least 10 times as much precipitation in wettest period as in driest period and 1950 average temperature of warmest quarter > 22 C Without dry season and average temperature of warmest quarter < 22 C 1550

7 Jatropha Productivity and Land Uses at Global Scale (Level I) Jatropha Results aggregated for land use types (JRC, year 2006): Sub-humid and semi-arid conditions (annual precipitation < 1500 mm) Excluding protected areas Economic viability (Seed productivity > 500 kg dry seed per year per ha) Existing Land Use Type Area (km2) Average Production (kg Seeds / ha * yr) Oil Production (Millions of barrels / yr) % of Global yearly Oil Consumption ( ) Cropland Post-flooding or irrigated croplands (or aquatic) 735, Rainfed croplands 1,578, Mosaic cropland (50-70%) / vegetation (grassland/shrubland/forest) (20-50%) 1,804, Mosaic vegetation (grassland/shrubland/forest) (50-70%) / cropland (20-50%) 2,030, Total Cropland 1, "Marginal" Natural and Semi-natural Terrestrial Vegetation Shrubs 3,532, , Natural and Semi-natural Terrestrial Vegetation Herbaceous 524, Natural and Semi-natural Terrestrial Vegetation - Sparse Vegetation 140, Bare Areas 50, Total Marginal 1, Forest 5,169, ,

8 Jatropha Productivity and Land Uses at Global Scale (Level I) If all the marginal land was converted (4,000,000 km sq), only about 4% of the total global oil consumption would be fulfilled. Most of marginal land is associated with shrubs (significant level of carbon stocks). Under global demand for oil, mixed croplands and forests can easily become target for Jatropha exploitation, where economic viable. Our study showed that Jatropha productivity might decrease on average because of climate changes.

9 Jatropha Productivity and Land Uses at Country Scale (Level II) Several differences arise on land use opportunities at country scale. Jatropha produced on marginal land can cover substantially oil demand of several countries.

10 Jatropha Productivity and Land Uses at Country Scale (Level II) Several differences arise on land use opportunities at country scale. Jatropha produced on marginal land can cover substantially oil demand of several countries.

11 Jatropha Productivity and Land Uses at Country Scale (Level II) Different levels of sustainabile use of Jatropha are found as we move from global to country scale. Existing policies promoting Jatropha at country level sometimes in contrast with real potentials of Jatropha and optimal land use availability. Discussion on biofuels sustainability, at least for the case of Jatropha, should be articulated both on country level and global. Big differences exist also because oil demand per person varies developing and developed countries.

12 Jatropha Productivity and Land Uses at Community Scale (Level III) For population density (persons per square km) > 10 and < 1000 and within a 10 X 10 km block (assumed as instance of community scale), we calculated where: Jatropha biofuel production from marginal land > oil consumption per capita x number of people

13 Jatropha Productivity and Land Uses at Community Scale (Level III) For population density (persons per square km) > 10 and < 1000 and within a 10 X 10 km block (assumed as instance of community scale), we calculated where: Jatropha biofuel production from marginal land > oil consumption per capita x number of people

14 Jatropha Productivity and Land Uses at Community Scale (Level III) Opportunity for Jatropha as biofuel fulfilling energy demands for marginal communities in Africa. Low levels of oil consumption per person is present in Africa, unlike for the rest of the world.

15 Jatropha Productivity and Land Uses: Discussion At global scale the high demand for oil could force large land use changes, otherwise engaged with food production and carbon stocks. Suitability of Jatropha to provide sustainable energy supply changes at different scales. At smaller scales different opportunities for sustainable use of Jatropha are more evident. Yet, is unrealistic to conceive local and country economies unsensitive to the global market. The crash of the Jatropha hype can become an opportunity for more sustainabile adoption of Jatropha as a partial energy solution.