How can agriculture help achieve the 2°C target?
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Presentation given by Lini Wollenberg, of the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), at the Global Landscapes Forum on 16 November 2016 in Marrakesh, Morocco. http://www.landscapes.org/
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How can agriculture help achieve the 2°C target?
- 1. Lini Wollenberg, CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) How can agriculture help achieve the 2°C target? 16 November 2016 Global Landscape Forum Session on Unexplained Big Wins for Climate Change through Landscape Restoration
- 2. 119 countries included mitigation in agriculture or economy- wide goals in Intended Nationally Determined Contributions 73% are developing countries
- 3. How much mitigation is needed in agriculture to stay below 2°C in 2100?
- 4. Calculating emissions for a 2°C world 2030 emissions reflect assumptions of each pathway Representative Concentration Pathway (RCP) 2.6 • RCP2.6 represents 2.6 watts/m2 radiative forcing in 2100, ~450 ppm CO2e • Limits warming to 0.3 to 1.7 °C during 2081 - 2100 • Represents non CO2 gases only • Agriculture will need to limit GHG emissions to 6-8 GtCO2e (out of all-sector total of 26 GtCO2e) by 2030
- 5. 0.92 1.19 1.23 0 0.5 1 1.5 Mitigation (GtCO2e/yr) RCP2.6 (IMAGE) (2) GCAM2.6 (3) MESSAGE2.5 (4) 1 GtCO2e/yr mitigation to stay within 2° C By 2030 (11-18% reduction) T
- 6. Livestock productivity, feed Efficient N fertilizer use How much can known mitigation practices contribute to the 2 °C goal? Water saving in paddy rice Used mitigation practices compatible with food production: • Cropland and paddy rice management • Grazing lands • Livestock • Agroforestry soils Not • Rewetting peatlands • Cropland set aside Soil carbon and agroforestry – not included as not compatible with RCPs IPCC AR5 Table 11.2
- 7. Calculated mitigation with global data sets 1. Bottom-up technology-by-technology estimates • Smith 2007, 2008, University of Aberdeen, IPCC • US $20 tons of CO2 1. Production efficiency gains using integrated assessment modeling (trade and location, production system) • Havlík 2014, IIASA • US $20 tons of CO2
- 8. Contributions of mitigation scenarios compared to the 2°C mitigation goal for agriculture 0.21 0.40 0.92 1.19 1.23 0.0 0.5 1.0 1.5 Mitigation (GtCO2e/yr) RCP2.6 (IMAGE) (2) GCAM2.6 (3) MESSAGE2.5 (4) Technical practices USD20/t (8) Efficiency practices USD20/t (9) 1 GtCO2e/yr mitigation to stay within 2° C
- 9. Plausible interventions will achieve only 21-40% of mitigation needed in agriculture by 2030
- 10. 10SAI - GRA
- 11. 0.76 0.31 1.71 1.77 2.00 1.37 4.31 1.20 0 1 2 3 4 5 Livestock supply chains Decrease food waste Shift dietary patterns Avoided deforestation by agriculture Soil carbon Mitigation (GtCO2e/yr)
- 12. Achieving the 2 °C target 1. Aspirational goal of 1 Gt by 2030 is a policy driven and science-based target. 2. Not mitigating in agriculture will increase the cost of mitigation in other sectors or reduce the feasibility of meeting the 2°C goal. 3. We need to radically expand technical and policy options for bigger impacts, e.g. reduced methane cows or rice, increasing and stabilizing carbon sequestration in soil and biomass, value chains.
- 13. • M. Richards • P. Smith • P. Havlík • M. Obersteiner • F.N. Tubiello • M. Herold • P. Gerber • S. Carter • A. Reisinger • D. van Vuuren • A. Dickie • H. Neufeldt • B.O. Sander • R. Wassmann • R. Sommer • J.E. Amonette • A. Falcucci • M. Herrero • C. Opio • R. Roman-Cuesta • E. Stehfest • H. Westhoek • I. Ortiz-Monasterio • T. Sapkota • M.C. Rufino • P.K. Thornton • L. Verchot • P.C. West • J.-F. Soussana • T. Baedeker • M. Sadler • S.Vermeulen • B.M. Campbell Thanks to co-Authors
Notas do Editor
- The Paris agreement surprised most of us with the strong showing of agriculture globally in the Intended nationally determined contributions—119 countries included agriculture (blue), 104 explicitly included agriculture. While the use of country pledges in the Paris Agreement was a brilliant way of reaching an agreement, as we all know, the mitigation pledges overall across all sectors were not enough and still leave the world at an unacceptable 3.5 to 3.6 degrees in 2100.
- To guide action, we therefore also require some idea of HOW MUCH mitigation needed to meet the policy goal of 2 degrees, or even 1.5. And ideally this should be broken down by sector to provide guidance to specific Ministries, industry and actors. So, in the last couple of years, group of us-about 20 organizations– have been working on this target for the agriculture sector asking… while maintaining food security.
- To calculate the target emissions, we used the scenario prepared for the IPCC that represents the 2 degree world – Representative concentration pathway 2.6, so named for its radiative forcing, and identified the agricultural emissions associated with this scenario in 2030We attributed 75% of global N emissions to agriculture. Caveat- we are only using this as indicative of emissions in 2030, recognizing that the level and trajectory of emissions under this scenario represent specific assumptions and only one pathway. RCP2.6 is in contrast to the high emissions scenario 8.5, representing a 4.9 degree increase in temp by 2100 over pre-industrial levels and 1370 ppm CO2. **** Background The RCP2.6 scenario is the most ambitious of the RCPs produced for the IPCC and represents the goal of achieving 2.6 W/m2radiative forcing in 2100, which equates to about 450 ppm of CO2e and is expected to limit warming to less than a 2-degree Celsius change in 2100 relative to pre-industrial conditions. It includes assumptions about economic activity, energy sources, population growth and other socio-economic factors (Van Vuuren et al. 2011). Cropland also increases by 0-20% (see details below) in the RCP2.6, but largely as a result of bio-energy production and stabilizes by 2030-2050. Land use emissions therefore drop. The use of grassland is more-or-less constant in the RCP2.6, as the increase in production of animal products is met through a shift from extensive to more intensive animal husbandry. C prices increase quickly to $80/tCO2 by 2030. For land-use scenarios, key uncertainties surround the development of food crop yields, and food demand. Land use RCPs need to be interpreted more carefully as here the linkages with the forcing levels are less direct (implying that many land-use projections might be consistent with the RCP levels). RCP2.6 was developed by the IMAGE modeling team of the PBL Netherlands Environmental Assessment Agency. The emission pathway is representative of scenarios in the literature that lead to very low greenhouse gas concentration levels. It is a “peak-and-decline” scenario; its radiative forcing level first reaches a value of around 3.1 W/m2 by mid-century, and returns to 2.6 W/m2 by 2100. In order to reach such radiative forcing levels, greenhouse gas emissions (and indirectly emissions of air pollutants) are reduced substantially, over time (Van Vuuren et al. 2007a). (Characteristics quoted from van Vuuren et.al. 2011) Van Vuuren RCP2.6 The baseline also projects an increase in the production of agricultural products over time. This increase is mostly driven by an increase in the global population, a modest increase in per capita consumption levels and a shift towards more meat intensive diets. Similarly as in the last few decades, the increase in global food production is mostly achieved through an increase in yield. While, for instance, global cereal production increased by 70% since 1970, crop land has increased only by about 6%. The reason for this has been a continuous increase in yields, about 1.5% annually for cereals on average at the global level. While this rate of improvement is likely to fall, so is the rate of increase in food demand. Assuming a somewhat lower than historically rate of yield improvement (e.g. for cereals an average rate of 0.75% per year over the whole period is assumed), global crop land for food production is projected to increase modestly up to 2050 and stabilize afterwards. Pasture land remains more or less stable from the present level, as a result of counteracting trends: 1) increasing meat demand, 2) a shift globally from extensive, grazing-based livestock farming to more intensive, feed-crop based forms of livestock farming, and 3) a stabilizing and after 2050 even decreasing global population. A review of baseline scenarios in the literature shows typically a projected increase in agricultural land use from 2000 to 2030 between 0% and 20% (with an average of 11%) (Rose et al. 2011; Smith et al. 2010). The projection that total global agricultural area (cropland plus grassland) is stabilized from 2030 onwards can thus be regarded as consistent with this range, but somewhat on the optimistic side. As a result of stabilizing agricultural area, emissions from the expansion of land use decrease during the 21st century, but do only approach zero after 2060 (annual emissions were around 1.5 GtC in recent historical years (Houghton 2008)). The total sum of greenhouse gas emissions, including land-use CO2, significantly increases under the baseline scenario from 11 GtC-eq in 20005 to 27 GtC-eq in 2100 (Fig. 3). This implies that the baseline scenario lies well within the literature range. Driven by these emissions, greenhouse gas concentrations rise substantially over time leading to a radiative forcing of about 7.2 W/m2 by 2100. The global mean temperature increase in 2100 in the baseline scenario is according to the IMAGE model about 4°C above pre- industrial levels, assuming a climate sensitivity of 3°C. The carbon prices that would be needed to induce the changes described above rise rapidly: from around 25 USD6/tC (or 7 USD/tCO2) in 2010 to slightly above 200 USD/tC (or 60 USD/tCO2) by 2020, 300 USD/tC (or 80 USD/tCO2) by 2030, and around 600 USD/tC (or 160 USD/tCO2) by 2050 (Fig. 9). The land use maps show that the projected changes in land use are only modest during the century—certainly in the absence of climate policy. However, a trend in agricultural area relocating from high income regions to low income regions can be noticed (Fig. 11). In the RCP2.6 scenario, a clear increase in bioenergy use becomes obvious also in terms of the area devoted to bioenergy. These areas occur near current agricultural areas and in particular in abandoned areas in high income regions. see Climatic Change (2011) 109:95–116 111 Fig. 11 Land use trends in the baseline and RCP2.6 mitigation scenario. Please note that harmonised land use trends for all RCPs are provided as described in Hurtt et al. (2011) Information about the different baselines: RCP8.5 emissions are based on the following scenario, RCP 8.5 is developed by the MESSAGE modeling team and the IIASA Integrated Assessment Framework at IIASA, Austria. The RCP 8.5 is characterized by increasing greenhouse gas emissions over time representative for scenarios in the literature leading to high greenhouse gas concentration levels. The underlying scenario drivers and resulting development path are based on the A2r scenario detailed in Riahi et al. (2007). Summary from Riahi 3.3 Land-use and land-cover change Some 1.6 billion ha of land are currently used for crop production, with nearly 1 billion ha under cultivation in the developing countries. During the last 30 years the world’s crop area expanded by some 5 million ha annually, with Latin America alone accounting for 35% of this increase. The potential for arable land expansion exists predominately in South America and Africa where just seven countries account for 70% of this potential. There is relatively little scope for arable land expansion in Asia, which is home to some 60% of the world’s population. These constraints are also reflected by the land-use change dynamics of the RCP 8.5 scenario. Projected global use of cultivated land in the RCP8.5 scenario increases by about 185 million ha during 2000 to 2050 and another 120 million hectares during 2050 to 2100. While aggregate arable land use in developed countries slightly decreases, all of the net increases occur in developing countries. Africa and South America together account for 85% of the increase. This strong expansion in agricultural resource use is driven by the socio-economic context assumed in the underlying emission scenario with a population increase to over 10 billion people in 2050 rising to 12 billion people by 2100. Even then yield improvements and intensification are assumed to account for most of the needed production increases: while global agricultural output in the scenario increases by 85% until 2050 and 135% until 2080, cultivated land expands respectively by 12% and 16% above year 2000 levels (Fig. 8). An important characteristic of RCP8.5 are transformative changes the biomass use for energy purposes from presently traditional (non-commercial) use in the developing world to commercial use in dedicated bio-energy conversion facilities (for power and heat) in the future. Globally the contribution of bioenergy is increasing in RCP8.5 from about 40 EJ in 2000 to more than 150 EJ by 2100. The vast majority of this biomass is harvested in forests, resulting in increased land-requirements for secondary managed forests. While total area of forests is declining in RCP8.5 (Fig. 8), the share of managed forests and harvested areas for biomass are thus increasing considerably. The latter grows from about 17 million ha to more than 26 million ha by 2100. Uncertainties in the interpretation of the underlying land developments are nevertheless very large. Hurtt et al. (2011) for example estimate about a factor of six higher land requirements for the same amount of wood harvest for the year 2000. Differences between the estimates increase over time. The results indicate the need for further harmonization of underlying data and definitions of carbon harvest in forest models. Figure from IPCC WGIII AR5 2014 http://www.ipcc.ch/pdf/assessment-report/ar5/wg3/ipcc_wg3_ar5_technical-summary.pdf
- To avoid the bias from use of any one model, we looked at the RCP2.6 for three different integrated assessment models (IMAGE, GCAM, MESSAGE ). The scenarios are only indicative of emissions in 2030 The models used similar assumptions to achieve the RCP2.6 pathway, including: significantly increased carbon prices relative to current prices, e.g. IMAGE used 80 USD per tCO2e in 2030 and 160 USD per tCO2e in 2050; increased food production to meet the needs of a larger population and shifts in consumer demand; and maintaining current food security percentages (i.e., food security is not eliminated). non-CO2 gases for the agricultural sector and do not include soil carbon sequestration. They do, however, include measures for bioenergy with carbon capture and storage (BECCS)- major wedge for negative emissions. Mitigation needed in each model was the difference between the 2 degree scenario and the baseline used by that model. We double checked these numbers against numbers using a standardized baseline from FAO and EPA, and they did not differ significantly.
- Given these constraints, the economic potentials indicate that rice management, livestock, and N efficiency are the big winners.
- With respect to your slide number 9, IIASA's current (unofficial) SSP2 reference level is close to EPA - +20% by 2030 compared to 2010. Indeed, getting on the RCP2.6 trajectory means to emit in 2030 some 870 MtCO2eq annually less than in the reference case. Total calorie consumption per capita is than about 2% lower than in the reference case - the overall growth in calories per capita from 2010 to 2030 is 5% only rather than 7%. CO2 tax is USD 35 per tCO2e in 2030.
- Compatibility with food security
- Evne with carbon at $20-50/t Co2
- Substantial mitigation possible based on estimates of what is feasible to adopt, but we also need 2 degree targets for these sectors Low and high estimates just represent different sources Agroforestry could also be on here- .39 Gt economic potential A more comprehensive goal for agriculture-related land use could be up to 4-6 GtCO2e/yr to meet the 2 degree