Coordinating AgMIP data and models across global and regional scales for 1.5°C and 2°C assessments
Cynthia Rosenzweig, Alex C. Ruane, John Antle, Joshua Elliott, Muhammad Ashfaq, Ashfaq Ahmad Chatta, Frank Ewert, Christian Folberth, Ibrahima Hathie, Petr Havlik, Gerrit Hoogenboom, Hermann Lotze-Campen, Dilys S. MacCarthy, Daniel Mason-D'Croz, Erik Mencos Contreras, Christoph Müller, Ignacio Perez-Dominguez, Meridel Phillips, Cheryl Porter, Rubi M. Raymundo, Ronald D. Sands, Carl-Friedrich Schleussner, Roberto O. Valdivia, Hugo Valin, Keith Wiebe
The Agricultural Model Intercomparison and Improvement Project (AgMIP) has developed novel methods for Coordinated Global and Regional Assessments (CGRA) of agriculture and food security in a changing world. The present study aims to perform a proof of concept of the CGRA to demonstrate advantages and challenges of the proposed framework. This effort responds to the request by the UN Framework Convention on Climate Change (UNFCCC) for the implications of limiting global temperature increases to 1.5°C and 2°C above pre-industrial conditions.
The protocols for the 1.5°C/2°C assessment establish explicit and testable linkages across disciplines and scales, connecting outputs and inputs from the Shared Socio-economic Pathways (SSPs), Representative Agricultural Pathways (RAPs), Half a degree Additional warming, Prognosis and Projected Impacts (HAPPI) and Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble scenarios, global gridded crop models, global agricultural economics models, site-based crop models and within-country regional economics models. The CGRA consistently links disciplines, models and scales in order to track the complex chain of climate impacts and identify key vulnerabilities, feedbacks and uncertainties in managing future risk.
CGRA proof-of-concept results show that, at the global scale, there are mixed areas of positive and negative simulated wheat and maize yield changes, with declines in some breadbasket regions, at both 1.5°C and 2°C. Declines are especially evident in simulations that do not take into account direct CO2 effects on crops. These projected global yield changes mostly resulted in increases in prices and areas of wheat and maize in two global economics models.
Regional simulations for 1.5°C and 2°C using site-based crop models had mixed results depending on the region and the crop. In conjunction with price changes from the global economics models, productivity declines in the Punjab, Pakistan, resulted in an increase in vulnerable households and the poverty rate.
This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'.
Coastal loss and damage for small islands
This commentary on a paper in Nature Sustainability reviews how the study quantifies the impacts of sea-level rise on small island states and estimates the impacts in terms of cost, land loss and population exposure across all small islands worldwide.
Adjusting 1.5°C climate change mitigation pathways in light of adverse new information
This study uses an integrated assessment model to explore how 1.5°C pathways could adjust in light of new adverse information, such as a reduced 1.5°C carbon budget, or slower-than-expected low-carbon technology deployment.
2030 targets aligned to 1.5°C: evidence from the latest global pathways
Our new method applies sustainability limits and minimises the need for carbon dioxide removal to set key 2030 global targets for renewables, fossil fuels and emissions.
The deployment length of solar radiation modification: an interplay of mitigation, net-negative emissions and climate uncertainty
Here, we investigate the deployment timescales of solar radiation modification and how they are affected by different levels of mitigation, net-negative emissions and climate uncertainty.
Emissions as usual: implications for the Safeguard Mechanism of LNG and coal mine projects
This report examines the implications of committed and proposed developments in the LNG and coal mining sectors for reform of Australia's Safeguard Mechanism.
Uncompensated claims to fair emission space risk putting Paris Agreement goals out of reach
Only halving emissions by 2030 can minimise risks of crossing cryosphere thresholds
1.5°C is still in reach to reduce the worst climate risks – but only with immediate mitigation action and shifting finance
How can the EU transform its economy to meet the 1.5°C goal?
What does the 1.5°C goal require from EU climate policy? This 4i-TRACTION policy brief analyses the latest 1.5°C-aligned scenarios and spells out what they imply for EU climate policy.
Institutional decarbonisation scenarios evaluated against the Paris Agreement 1.5°C goal
This study analyses six institutional decarbonisation scenarios published between 2020 and mid 2021 (including four from the oil majors and two from the International Energy Agency. It finds that most of the scenarios would be classified as inconsistent with the Paris Agreement as they fail to limit warming to ‘well below 2 ̊C, let alone 1.5 ̊C, and would exceed the 1.5 ̊C warming limit by a significant margin.