Search for: All records

Abstract Groundwater stress, a critical challenge for global water security and food production, has intensified due to the interaction of global change drivers and rapidly evolving local conditions. This paper investigates the individual and combined impacts of water availability, heat, population growth, income dynamics, and technological advancements on global groundwater stress over a historical period from 1997 to 2017. Utilizing the gridded Simplified International Model of agricultural Prices, Land use, and the Environment (SIMPLE-G), the study attributes local changes in water and land use patterns to these key global drivers. Furthermore, it evaluates an alternative, counterfactual scenario in which sustainable management interventions for groundwater resources are implemented over these two historical decades. The analysis quantifies the historical contribution of each global change driver to local groundwater stress and measures the economic benefits of a scenario in which groundwater extraction caps and improved technology adoption began in 1997. We find that implementing a groundwater extraction cap combined with irrigation investment beginning in 1997 could have reduced global groundwater withdrawals by more than 34% by 2017, preserving over 5 trillion cubic meters of groundwater in aquifers, with the greatest reductions occurring in South Asia and the Western United States. This study contributes to the local-global analysis of the effects of global socio-economic drivers on earth systems through high-resolution, scenario-based modeling. 

ABSTRACT Current science indicates that warming and elevated atmospheric CO₂will have ambiguous results for crop productivity depending on crop type and geographic location, whereas increased heat stress makes livestock and human labor less productive. The differential impacts across regions will alter comparative advantage and shift the patterns of global trade. This paper employs an economywide trade model to assess all three types of productivity shocks under a 3°C global warming scenario. We find that the widening agricultural trade deficits persist, even as the overall US trade balance improves due to enhanced investment inflows. 

ABSTRACT In a series of highly cited papers over the period of 2009–2023, earth system scientists have identified a set of nine planetary boundaries that must not be breached if we wish to avoid catastrophic consequences for nature and humanity. These range from well‐mixed, global boundaries, such as climate‐altering atmospheric greenhouse gas concentrations, to localized limits on freshwater availability and reactive nitrogen entering the environment. Recent estimates suggest that six of the nine planetary boundaries have already been breached. The food system is a key driver of these exceedances and, therefore, must play a key role in any solutions. However, the establishment of these boundaries and the analysis of potential solutions have often been devoid of economic considerations. Furthermore, in the case of several of these planetary boundaries, limited attention has been given to the economic policies that might allow society to address them, as well as the likely synergies and tradeoffs across economic policies targeted to individual objectives. This paper seeks to bring further economic analysis to bear on the quantitative assessment of global and local economic policies aimed at respecting these planetary boundaries, concluding with seven lessons to inform future research on this topic. 

Research investments in crop improvements, including by national and international agricultural research centers, have made significant contributions to raising yields of staple food crops in developing countries. Although mostly intended to improve food security and rural incomes, innovations in crop production also have major implications for the environment. Building on the latest productivity estimates from historical crop improvements in developing countries and using a gridded (0.25 degrees) equilibrium model of global agriculture, we assess the impacts of improved crop varieties on cropland use, threatened biodiversity, and terrestrial carbon stocks over 1961–2015. We replicate a historical baseline and produce a counterfactual scenario which shows the impact of omitting productivity improvements from these technologies. The results show that higher crop productivity generally lowered commodity prices, which reduced incentives to expand cropland except in those areas where productivity gains outweighed price declines. The net global effect of technology adoption was to limit conversion of natural habitat to agricultural use, although it did cause cropland to expand in some areas. We estimate that adoption of improved crop varieties in developing countries saved on net 16.03 [95% CI, 12.33 to 20.89] million hectares worldwide. With more natural habitat preserved, around 1,043 [95% CI, 616 to 1,503] threatened animal and plant species extinctions were avoided over this period. In addition, net land use savings from the improved crop varieties resulted in avoided terrestrial greenhouse gas (GHG) emissions of around 5.35 [95% CI, 3.75 to 7.22] billion metric tons CO₂equivalent retained in terrestrial carbon stocks. 

The risk of national food supply disruptions is linked to both domestic production and food imports. But assessments of climate change risks for food systems typically focus on the impacts on domestic production, ignoring climate impacts in supplying regions. Here, we use global crop modeling data in combination with current trade flows to evaluate potential climate change impacts on national food supply, comparing impacts on domestic production alone (domestic production impacts) to impacts considering how climate change impacts production in all source regions (consumption impact). Under 2°C additional global mean warming over present day, our analysis highlights that climate impacts on national supply are aggravated for 53% high income and 56% upper medium income countries and mitigated for 60% low- and 71% low-medium income countries under consumption-based impacts compared to domestic impacts alone. We find that many countries are reliant on a few mega-exporters who mediate these climate impacts. Managing the risk of climate change for national food security requires a global perspective, considering not only how national production is affected, but also how climate change affects trading partners. 

Agriculture will play a central role in meeting greenhouse gas (GHG) emission targets, as the sector currently contributes ∼22% of global emissions. Because emissions are directly tied to resources employed in farm production, such as land, fertilizer, and ruminant animals, the productivity of input use tends to be inversely related to emissions intensity. We review evidence on how productivity gains in agriculture have contributed to historical changes in emissions, how they affect land use emissions both locally and globally, and how investments in research and development (R&D) affect productivity and therefore emissions. The world average agricultural emissions intensity fell by more than half since 1990, with a strong correlation between a region's agricultural productivity growth and reduction in emissions intensity. Additional investment in agricultural R&D offers an opportunity for cost-effective (