Search Climate Insights Directory

The Union of Concerned Scientists finds that genetic engineering has contributed minimally to U.S. crop yield increases, with the majority of gains attributed to traditional breeding and other agricultural methods. The briefing distinguishes between intrinsic yield (potential) and operational yield (actual), concluding that GE crops have not increased intrinsic yield and provided only marginal operational gains, primarily in specific insect-resistant corn varieties. It advocates for shifting research and funding toward traditional breeding, genomic approaches, and agro-ecological farming, particularly for developing regions.

The report concludes that genetic engineering has failed to increase the intrinsic yield of any major food or feed crops and has provided only minimal gains in operational yield, primarily through Bt corn. Most yield increases in U.S. agriculture are attributed to traditional breeding and improved agricultural practices rather than GE traits.

The report projects that Indiana will face significantly hotter summers, increased flooding, and agricultural disruptions if heat-trapping emissions continue to rise. It highlights severe risks to public health from heat waves and poor air quality, and suggests that the state transition from its heavy reliance on coal-fired power to renewable energy and energy efficiency to mitigate these effects.

The report analyzes how global warming affects Pennsylvania's environment and economy, projecting severe risks under a higher-emissions scenario, such as the disappearance of snowmobiling, declines in dairy and fruit yields, and increased urban heat stress. It advocates for a transition to clean energy, citing Pennsylvania's role as the third-highest fossil fuel emitter in the U.S., and suggests specific adaptation strategies for infrastructure and natural resources.

The document describes two techniques for creating elicited probability tables (EPTs) to simplify the process of building Bayesian networks when measured data is unavailable or insufficient. Both methods utilize a user-defined "typical distribution" to represent a normal state of affairs. The first method, "Influence Weights," assumes that changes in parent nodes independently affect the child node and is best used when parent and child nodes share the same states. The second method, "Likelihood," uses a log-likelihood approach to model how parent nodes shift the child node's probability away from the typical distribution, making it suitable for cases where parent nodes have different states than the child node.

The report argues that genetically modified (GM) crops provide no substantive environmental, social, or economic benefits. It highlights a significant increase in pesticide use, particularly glyphosate, due to the emergence of herbicide-resistant weeds in the US, Brazil, and Argentina. The document further contends that GM crops do not increase yields—citing evidence that Roundup Ready soy may actually suffer yield losses—and that they do not address global hunger, as most are used for animal feed or biofuels in wealthy nations. Additionally, it criticizes the concentration of seed control by a few multinational corporations, which increases costs and restricts farmers' ability to save seeds.

The report argues that GM crops provide no ecological, social, or economic benefits. It highlights that herbicide-tolerant (HT) varieties promote the development of resistant weeds, leading to increased pesticide application in the US, Brazil, and Argentina. The document further asserts that GM crops do not increase yields or food security, as most are used for animal feed or biofuels rather than human consumption, and that seed monopolies increase costs for farmers.

The report argues that GM crops, primarily herbicide-tolerant and insect-resistant varieties of soya, maize, cotton, and canola, have not increased yields and have instead driven a rise in pesticide use due to the emergence of resistant weeds. It highlights the monopolization of the seed supply by a few corporations, specifically Monsanto, and documents the negative socio-economic impacts on small farmers in the US, India, and South America, including increased debt and rural poverty.

The report argues that GM crops, particularly herbicide-tolerant (HT) and Bt varieties, have failed to deliver promised benefits in yield and poverty reduction. It documents a significant increase in pesticide use and the emergence of herbicide-resistant weeds in the US, Argentina, and Brazil. The document further highlights the monopolization of the seed market by a few firms, specifically Monsanto, and the resulting economic pressure and legal harassment of farmers. Case studies in India, China, and South Africa suggest that yield increases are often due to weather or irrigation rather than GM technology, while small farmers face increased debt and vulnerability.

The document examines how ground-level ozone (O3) reduces crop yields in South Asia, specifically within the Indo-Gangetic Plain. It finds that current O3 concentrations cause yield losses between 5% and 35%, resulting in estimated annual economic losses of approximately US$ 3.9 billion for staple crops. The brief highlights that O3 concentrations are projected to increase more rapidly in South Asia than in any other global region by 2030. It argues that these impacts may be more immediate than those of climate change and could contribute to the recent decline in crop yield growth in the region. The authors recommend international cooperation to reduce precursor emissions, the development of O3-resistant crop varieties, and improved integration of air quality and food security into policy frameworks.

The report identifies a warming and potentially drier trend for the Great Lakes region, predicting significant temperature increases and shifts in precipitation patterns by the end of the 21st century. These changes are expected to disrupt aquatic ecosystems, reduce forest diversity, and create economic risks for agriculture and shipping. The document advocates for a three-pronged approach: reducing greenhouse gas emissions, minimizing local environmental pressures, and planning for climate adaptation.

The report examines the deployment of Bt 176 GM corn in Spain, highlighting a lack of independent monitoring and the failure of the Spanish government to enforce mandatory 'Prevention Plans'. It documents cases of genetic contamination in organic crops in Navarra and presents evidence from the ITG-A suggesting that corn borers are developing resistance to the Bt toxin. The document further argues that GM corn does not provide superior yields compared to conventional varieties and poses risks to non-target species and human health via antibiotic-resistance genes.

The report examines the deployment of first-generation GMO crops in the US and Argentina. It finds that while RR soybeans facilitate no-till farming and replace more toxic herbicides, they often result in a 5-10% yield drag and increased total herbicide volume. The author warns that high selection pressure, particularly in Argentina, risks accelerating weed resistance and shifts. Additionally, the paper highlights emerging concerns regarding glyphosate's impact on soil microbial communities, specifically the buildup of Fusarium fungi, and potential impairments to plant immune responses and nitrogen fixation.

The report assesses the vulnerability of Canadian Prairie agriculture to climate change, highlighting the historical impact of droughts in the 1930s and 1988. It projects that while warming may extend growing seasons and open northern lands for cultivation, increased evaporation and potential precipitation deficits could lead to more frequent and severe droughts, reducing average potential yields by 10-30%. The document emphasizes the need for policy shifts to incentivize sustainable land management and diversification, noting that current income protection programs may discourage adaptation. It also discusses Canada's potential shift in global competitive advantage, suggesting increased opportunities for wheat and corn exports if other global regions face diminished production.

The report projects that global food requirements will increase significantly by 2050, driven by population growth and rising dietary standards in less developed countries (LDCs). While theoretical land and yield potentials exist, the report argues that meeting this demand will require massive increases in crop yields, a substantial expansion of cultivated land in Africa and Latin America, and a six-fold increase in cereal exports from developed regions. It highlights critical risks including soil degradation, water scarcity, and the environmental impact of forest clearance, suggesting a 'doubly green' revolution focused on sustainable intensification and policy reform to avoid food insecurity.

The document details how climate change causes direct health trauma through heat, wildfires, and storms, and indirect impacts via natural and human systems. It highlights WHO projections for increased deaths from heat and diarrhoeal diseases, the expansion of vector-borne diseases like malaria and dengue, and the risk of widespread undernutrition. Additionally, it addresses the socio-economic drivers of health decline, including extreme poverty, forced migration, and increased conflict, while identifying highly vulnerable populations such as indigenous peoples and those in low-income countries.

The report highlights that tropospheric ozone is a potent greenhouse gas and air pollutant responsible for approximately 0.23°C of present-day warming and nearly 500,000 premature deaths annually. It is not emitted directly but forms from precursors like methane, nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOCs), and carbon monoxide (CO). The document identifies a significant gap in global climate strategies, noting that tropospheric ozone is largely absent from the Paris Agreement and most Nationally Determined Contributions (NDCs). It provides sector-specific policy levers—ranging from methane capture in oil and gas to electric vehicle adoption in transport—and presents case studies from Los Angeles, Mexico City, Beijing, and Europe to demonstrate the effectiveness of targeted pollution control. The report concludes with recommendations for policymakers to adopt multi-pollutant approaches, for scientists to fill knowledge gaps in regional climate effects, and for funders to increase the currently insufficient international development funding for outdoor air pollution.

The report finds that potential yields for dry beans, maize, pepper, and tomato in the Cayo District are projected to decline over the 21st century, with maize production potentially falling to just over 25% of 20th-century values. Livestock are expected to face increased thermal stress and reduced natural food availability as grassland biomass decreases. However, the study emphasizes a significant 'yield gap' between potential and actual yields due to poor technological efficiency, suggesting that improving management practices and irrigation could lead to a net increase in actual production despite declining potential yields.

A case study of an 80-hectare sugarcane cooperative in KwaZulu-Natal demonstrates that switching from tractor-mounted boom sprayers to precision drone spraying reduced total spraying costs by approximately 25% and chemical usage by 20–30%. The transition eliminated operational downtime after rainfall and reduced labour requirements from 10 man-days per hectare to 2 man-days. These efficiencies, combined with yield increases of 6–12.5 tonnes per hectare and a 2 percentage point increase in estimated recoverable crystal (ERC), resulted in a net financial benefit of approximately R8,400 per hectare per year, totaling R672,000 for the cooperative. The document notes that direct drone ownership, costing between R250,000 and R400,000, has an estimated payback period of 1–1.5 seasons, while shared-service models lower the entry barrier for smallholders.

Climate change is projected to increase temperatures in South Africa at double the global average, leading to water scarcity, reduced crop yields for staples like maize and wheat, and increased risks for small-scale farmers and marginalized communities. The document argues that a market-led response will exacerbate inequality and instead advocates for a just transition involving resource redistribution, agro-ecological practices, and a universal basic income grant to build resilience.