The impacts of increased heat stress events on wheat yield under climate change in China

China is the largest wheat producing country in the world. Wheat is one of the two major staple cereals consumed in the country and about 60% of Chinese population eats the grain daily. To safeguard the production of this important crop, about 85% of wheat areas in the country are under irrigation or high rainfall conditions. However, wheat production in the future will be challenged by the increasing occurrence and magnitude of adverse and extreme weather events. In this paper, we present an analysis that combines outputs from a wide range of General Circulation Models (GCMs) with observational data to produce more detailed projections of local climate suitable for assessing the impact of increasing heat stress events on wheat yield. We run the assessment at 36 representative sites in China using the crop growth model CSM-CropSim Wheat of DSSAT 4.5. The simulations based on historical data show that this model is suitable for quantifying yield damages caused by heat stress. In comparison with the observations of baseline 1996-2005, our simulations for the future indicate that by 2100, the projected increases in heat stress would lead to an ensemble-mean yield reduction of –7.1% (with a probability of 80%) and –17.5% (with a probability of 96%) for winter wheat and spring wheat, respectively, under the irrigated condition. Although such losses can be fully compensated by CO2 fertilization effect as parameterized in DSSAT 4.5, a great caution is needed in interpreting this fertilization effect because existing crop dynamic models are unable to incorporate the effect of CO2 acclimation (the growth enhancing effect decreases over time) and other offsetting forces

Discutir saúde e imigração no contexto atual de intensa mobilidade humana

Este artigo aborda as relações entre imigração e saúde no Brasil, partindo de uma abordagem histórica que busca contextualizar o debate no país desde o século XIX até os dias atuais. A problematização dessas relações destaca os desafios das políticas sociais de acolhimento e integração dos imigrantes no mundo globalizado. Por meio da revisão bibliográfica sobre imigração e saúde no contexto brasileiro e internacional, buscamos prioridades que se impõem à saúde coletiva em face da intensa mobilidade humana atual. As desigualdades socioeconômicas marcam a experiência de parte dos imigrantes, expondo estas populações a uma maior vulnerabilidade, adoecimento e menor qualidade de vida. Apontamos a necessária promoção da equidade de acesso à saúde, prevenção contra a discriminação, ampliação das políticas públicas, formação dos profissionais e oferta de serviços adaptados, abordando a temática das migrações como determinante social de saúde