Our findings demonstrate the sensitivity of technology adoption to land productivity and market isolation, but there are numerous other factors that are likely to influence technology adoption patterns. Salient factors include energy prices, landholder heterogeneity, land tenure status, and non-agricultural motivations for agricultural land use. Energy prices will have a strong influence on the size of the production cost gap between lower input and higher input management systems . Factors such as educational level, age, access to inputs, access to credit, and farm size have all also been shown to mediate the technology adoption process in agricultural systems . Land tenure status is a strong determinant of land user behavior. In Brazil, as in much of the tropics, land tenure remains a highly uncertain affair with context-contingent implications for agricultural technology adoption patterns and thus the efficacy of terrestrial climate mitigation efforts .Global economic models of land use do not explicitly represent non-agricultural motivations for agricultural land use. These factors could attenuate the efficacy of the tax and subsidy instruments of inducing adoption of intensive alternatives. Thus it would be wise to consider the adoption rates we model as an upper bound of the efficacy of the proposed policy. All across the agricultural landscape,container grown raspberries factors such as risk aversion, cultural preferences, supply chain structure, and imperfect information can dampen adoption of intensive technologies.

Even on the large farms of the U.S. Midwest, higher commodity prices do not always boost yields according to model estimates . These confounding effects are most pronounced at extensive agricultural margins, where most Brazilian cattle ranching area can be found. They also have non-cattle-product-producing motives for ownership that play important roles in management decisions . Maintaining cattle on Brazilian pasture can help to secure tenure, obtain access to government subsidies, to hedge against inflation, and to speculate on increases in land values. Cattle ranching may also be explained by cultural reasons that are not utility maximizing . By underestimating these non-agricultural motivations, the model may overestimate the likelihood of technology adoption in response to subsidies and taxes . In such cases, alternative landholding activities may be more attractive options for landholders to allocate their land, labor, and capital than adoption of intensive alternatives. On farms where instruments are applied, attractive alternatives could mean a negative opportunity cost for intensification technologies that appear profitable relative to business as usual cattle ranching where the only output is cattle products. As a result, agents might prefer to allocate land, labor and capital to alternative activities besides intensification even if intensification is profitable. Where adoption occurs, leads to intensification, and as a result drives down prices, the land sparing effect at the extensive margin could also be dampened by non-agricultural motivations for cattle ranching.

Non-agricultural activities could keep a greater proportion of ranching profitable under revenue losses from cattle product price declines. This could limit the land sparing effect.If they are to be effective, instruments of the sort we model will require more research and data gathering on the structure and function of Brazilian cattle systems and continued improvement in land use governance institutions in Brazil and beyond. Specific tasks include furthering agricultural data collection and monitoring, improving land tenure institutions, and developing adaptive governance rooted in sound regulatory science. Improved land tenure institutions are foundational to advances in Brazilian land use governance including the implementation of effective intensification instruments. In recent years, Brazilian land tenure institutions have streamlined and the introduction of geo-spatial tools has greatly improved the uptake and transparency of the tenure regularization. Nevertheless, overall rates of participation in these fast-track programs are low, competing/conflicting tenure claims persist, and the tenure granting process itself may still in some instances induce increased land clearing. This would stymie the pre-requisite for adaptive governance in the early stages of such a policy. Brazil has relatively advanced agriculture statistics capacity, but several missing elements, if not remedied, will undermine efforts to monitor and evaluate the effectiveness of the policy instruments like the ones we model. The most glaring absence is the infrequent assessment of pasture quantity and quality by census or by remote sensing. At present, pasture area is assessed just once a decade.

Without more frequent updates it is not possible to discern key parameters of the land use change process. Consequentially, it would not be possible to monitor and evaluate the effects of intensification instruments. Our focus on adaptive governance rooted in monitoring and evaluation stems from the aforementioned data gaps and also scientific uncertainty of Brazilian cattle systems. Efficacy is likely to require trial and error. Since the baseline farm characteristics and trends are typically unknown, it is crucial to also monitor systems of production in a control group of ranches. Doing this well would require a surge in data, enforcement, and regulatory science. One of the greatest and likely costliest challenges stems from the inherently unobservable nature of the GHG outcomes of intensification instruments. The magnitude and even the direction of the GHG impacts of intensification instruments will not be reliably indicated by superficial production system characteristics such as absolute or relative intensity. Instead, it will be necessary to mechanistically monitor production systems to model the multiple mechanisms by which cattle systems shape the global land use process. Such modeling is necessary to conduct because the global land use process has no replicates and thus the effects of the policies cannot be meaningfully observed. Additionality has long been a controversial pre-requisite for land use climate mitigation strategies . The intensification technologies we model are already quite common across the Brazilian cattle sector and their use is already growing. The policies that we have devised are designed to accelerate the intensification process on laggard ranches simply to approximate the behavior of leading ranches. Therefore, the presence of the technologies on treated ranches would be insufficient evidence of a policy effect. To ensure policies are accelerating adoption, it will be necessary to use pilot and trial programs to better discern how the policies influence land users. To do so, it would be necessary to monitor both treated ranches and a control group of ranches. Such an approach would require an articulating and updating experimental design and a strong backbone of benchmarks. In the cattle sector,blueberry plant pot determining productivity benchmarks and monitoring intensification activities would require substantially improved agricultural earth observation and monitoring of the movement of cattle. The distinction between additional and non-additional intensification is important for informing and refining the intervention mechanism, but it should not necessarily be the approach for the policy itself. Penalizing early adopters of intensive technologies could slow the rate of endogenous adoption and thereby attenuate policy gains. Thus the trial and pilot periods should be used to explore the costs and benefits of need-blind payments to ranchers. The prospects of an inframarginal subsidy might break with convention of land climate mitigation, but it could boost policy effectiveness .Metam sodium, 1, 3-dichloropropene , methyl bromide, and chloropicrin are high use agricultural fumigants that account for about 20% of the annual pesticide usage in California . These fumigants are known respiratory toxicants and were the top four pesticides ranked by chronic health risk based on a risk assessment conducted in the early 2000s . Methyl bromide, 1, 3-DCP and chloropicrin have also been identified as the top three pesticides of public health concern used near schools .

An evaluation of pesticide drift-related illnesses in 11 states found that the largest percentage of cases were related to fumigant applications, indicating the particularly hazardous nature of these substances . Methyl bromide was banned by the Montreal Protocol due to harmful effects on the ozone layer and is currently being phased out of use, resulting in increased usage of chloropicrin, metam sodium and 1,3-DCP in recent years . Cases of acute methyl bromide exposure in adults and children have produced symptoms such as shortness of breath, pulmonary edema, cough, respiratory irritation and respiratory arrest . In the Agricultural Health Study, which examines pesticides and health in a cohort of pesticide applicators and their families, methyl bromide application was associated with higher prevalence of chronic bronchitis in nonsmoking wives of farmers . Metam sodium degrades into methylisothiocyanate, which is known to irritate respiratory tissue , and then further breaks down into methylisocyanate, the active ingredient responsible for the Bhopal tragedy that killed more than 3500 people . In the Bhopal tragedy the most common and serious problems were related to respiratory symptoms . Cases of metam sodium-related illnesses have involved minor respiratory symptoms including coughing and dyspnea . A metam sodium spill in California resulted in persistent respiratory health problems for nearby residents . In a case study of drift from a metam sodium application in California, an association between cases of respiratory illness in nearby residents and proximity to the application area was observed . Increased respiratory symptoms have been reported as a result of community exposure to chloropicrin following application . A larger analysis of chloropicrin-related illness in California from 1992–2003 found that 54% of cases involved respiratory irritation . Toxicology studies conducted on rodents have shown that 1, 3-DCP exposure is related to benign lung tumor incidence as well as enlargement of the respiratory epithelium . Several epidemiological studies have found an association between occupational exposure to pesticides and an increased risk of respiratory symptoms and asthma . No research to date has been conducted on fumigant exposure and respiratory health in children, who are particularly vulnerable to inhalation risk due to relatively higher inhalation-rate-to-body-weight ratios . There are no biomarkers available to assess human exposure to fumigants in epidemiologic studies . Residential proximity to fumigant use is currently the best method to characterize potential exposure to fumigants. California has maintained a Pesticide Use Reporting system which requires commercial growers to report all agricultural pesticide use since 1990 . A study using PUR data showed that methyl bromide use within ~8 km radius around monitoring sites explained 95% of the variance in methyl bromide air concentrations, indicating a direct relationship between nearby agricultural use and potential community exposure . In the present study, we investigate associations of residential proximity to agricultural fumigant usage during pregnancy and childhood with respiratory symptoms and pulmonary function in 7-year-old children participating in the Center for the Health Assessment of Mothers and Children of Salinas , a longitudinal birth cohort study of primarily low-income Latino farm worker families living in the agricultural community of the Salinas Valley, California. We enrolled 601 pregnant women in the CHAMACOS study between October 1999 and October 2000. Women were eligible for the study if they were ≥18 years of age, <20 weeks gestation, planning to deliver at the county hospital, English or Spanish speaking, and eligible for low-income health insurance . We followed the women through delivery of 537 live-born children. Research protocols were approved by The University of California, Berkeley, Committee for the Protection of Human Subjects. We obtained written informed consent from the mothers and children’s oral assent at age 7. Information on respiratory symptoms and use of asthma medication was available for 347 children at age 7. Spirometry was performed by 279 of these 7-year-olds. We excluded participants from the prenatal analyses for whom we had residential history information for less than 80% of their pregnancy. We excluded participants from the postnatal analyses for whom we had residential history information for less than 80% of the child’s lifetime from birth to the date of the 7 year assessment. Prenatal estimates of proximity to fumigant applications and relevant covariate data were available for 257 children and postnatal estimates of proximity to fumigant applications and relevant covariate data were available for 276 children for whom we obtained details of prescribed asthma medications and respiratory symptoms. Prenatal estimates of proximity to fumigant applications and relevant covariate data were available for 229, 208, and 208 children for whom we had FEV1, FVC and FEF25–75 measurements, respectively. Postnatal estimates of proximity to fumigant applications and relevant covariate data were available for 212, 193, and 193 children with FEV1, FVC and FEF25–75 measurements, respectively.