A Few Interventions and Offerings from Five Movement Lawyers to the Access to Justice Movement

We are five lawyers who occupy very different corners of justice work. We are civil rights, human rights, and criminal defense lawyers, and we have worked at and managed legal services programs. We have taught law at law schools and universities and have built our own organizations. We currently work in interdisciplinary spaces with community organizers, funders, and other stakeholders in the justice system. As diverse as our perspectives are, we share a common belief that any mobilization around access to justice fails if it does not center the vision and strategies of larger social justice movements. We share here our collective calls to action to the legal community—and the allies that support and resource legal services—to expand our mission beyond chasing a standard of fairness that is impossible to achieve as long as we have deeply embedded structural and systemic inequity. Instead, let us reimagine what our communities actually need to be safe, free, and to live in our fullest humanity. We believe the role of movement lawyers is to use the law as a tool of social change, at the direction of communities most impacted by injustice. When we focus our lawyering on listening to community organizers, clients, and activists with a broader vision for social change, we can become partners in transforming systems, rather than simply making them more hospitable

Heterogeneity and chemical reactivity of the remote troposphere defined by aircraft measurements

The NASA Atmospheric Tomography (ATom) mission built a photochemical climatology of air parcels based on in situ measurements with the NASA DC-8 aircraft along objectively planned profiling transects through the middle of the Pacific and Atlantic oceans. In this paper we present and analyze a data set of 10 s (2 km) merged and gap-filled observations of the key reactive species driving the chemical budgets of O3 and CH4 (O3, CH4, CO, H2O, HCHO, H2O2, CH3OOH, C2H6, higher alkanes, alkenes, aromatics, NOx, HNO3, HNO4, peroxyacetyl nitrate, other organic nitrates), consisting of 146,494 distinct air parcels from ATom deployments 1 through 4. Six models calculated the O3 and CH4 photochemical tendencies from this modeling data stream for ATom 1. We find that 80 %&ndash;90 % of the total reactivity lies in the top 50 % of the parcels; and 25 %&ndash;35 %, in the top 10 %, supporting previous model-only studies that tropospheric chemistry is driven by a fraction of all the air. In other words, accurate simulation of the least reactive 50 % of the troposphere is unimportant for global budgets. Surprisingly, the probability densities of species and reactivities averaged on a model scale (100 km) differ only slightly from the 2 km ATom data, indicating that much of the heterogeneity in tropospheric chemistry can be captured with current global chemistry models. Comparing the ATom reactivities over the tropical oceans with climatological statistics from six global chemistry models, we find generally good agreement with the reactivity rates for O3 and CH4. In the Pacific but not Atlantic, however, models distinctly underestimate O3 production below 2 km, and this can be traced lower NOX levels than observed. Attaching photochemical reactivities to measurements of chemical species allows for a richer, yet more constrained-to-what-matters, set of metrics for model evaluation.</p

A Few Interventions and Offerings from Five Movement Lawyers to the Access to Justice Movement

We are five lawyers who occupy very different corners of justice work. We are civil rights, human rights, and criminal defense lawyers, and we have worked at and managed legal services programs. We have taught law at law schools and universities and have built our own organizations. We currently work in interdisciplinary spaces with community organizers, funders, and other stakeholders in the justice system. As diverse as our perspectives are, we share a common belief that any mobilization around access to justice fails if it does not center the vision and strategies of larger social justice movements. We share here our collective calls to action to the legal community—and the allies that support and resource legal services—to expand our mission beyond chasing a standard of fairness that is impossible to achieve as long as we have deeply embedded structural and systemic inequity. Instead, let us reimagine what our communities actually need to be safe, free, and to live in our fullest humanity. We believe the role of movement lawyers is to use the law as a tool of social change, at the direction of communities most impacted by injustice. When we focus our lawyering on listening to community organizers, clients, and activists with a broader vision for social change, we can become partners in transforming systems, rather than simply making them more hospitable

Heterogeneity and chemical reactivity of the remote troposphere defined by aircraft measurements

The NASA Atmospheric Tomography (ATom) mission built a photochemical climatology of air parcels based on in situ measurements with the NASA DC-8 aircraft along objectively planned profiling transects through the middle of the Pacific and Atlantic oceans. In this paper we present and analyze a data set of 10s (2km) merged and gap-filled observations of the key reactive species driving the chemical budgets of O3 and CH4 (O3, CH4, CO, H2O, HCHO, H2O2, CH3OOH, C2H6, higher alkanes, alkenes, aromatics, NOx, HNO3, HNO4, peroxyacetyl nitrate, other organic nitrates), consisting of 146494 distinct air parcels from ATom deployments 1 through 4. Six models calculated the O3 and CH4 photochemical tendencies from this modeling data stream for ATom 1. We find that 80%-90% of the total reactivity lies in the top 50% of the parcels and 25%-35% in the top 10%, supporting previous model-only studies that tropospheric chemistry is driven by a fraction of all the air. In other words, accurate simulation of the least reactive 50% of the troposphere is unimportant for global budgets. Surprisingly, the probability densities of species and reactivities averaged on a model scale (100km) differ only slightly from the 2km ATom data, indicating that much of the heterogeneity in tropospheric chemistry can be captured with current global chemistry models. Comparing the ATom reactivities over the tropical oceans with climatological statistics from six global chemistry models, we find excellent agreement with the loss of O3 and CH4 but sharp disagreement with production of O3. The models sharply underestimate O3 production below 4km in both Pacific and Atlantic basins, and this can be traced to lower NOx levels than observed. Attaching photochemical reactivities to measurements of chemical species allows for a richer, yet more constrained-to-what-matters, set of metrics for model evaluation

The POLARCAT Model Intercomparison Project (POLMIP): overview and evaluation with observations

International audienceA model intercomparison activity was inspired by the large suite of atmospheric chemistry observations made during the International Polar Year (2008) in the Arctic. Nine global and two regional chemical transport models have performed simulations for 2008 using a common emissions inventory to quantify the differences in model chemistry and transport schemes. This paper summarizes the models and compares their simulations of ozone and its precursors, and presents an evaluation of the simulations using a variety of surface, balloon, aircraft and satellite observations. Despite using the same emissions, large differences are seen among the models. Differences in a number of model parameters are identified as contributing to differences in the modelled chemical species, including cloud fields and photolysis rates. The largest differences among models, and between models and observations, are in NOy partitioning (PAN vs. HNO3) and in oxygenated volatile organic compounds (VOCs) such as acetaldehyde and acetone. Comparisons to surface site measurements of ethane and propane indicate that the emissions of these species are significantly underestimated. While limited in spatial and temporal coverage, the aircraft measurements provide a simultaneous evaluation of many species. Satellite observations of NO2 from OMI have been used to evaluate the models over source regions, indicating anthropogenic emissions are underestimated in East Asia, but fire emissions are generally overestimated. The emission factors for wildfires in Canada are evaluated using the correlations of VOCs to CO in the model output in comparison to enhancement factors derived from aircraft observations, showing reasonable agreement for methanol and acetaldehyde, but underestimate of ethanol, propane and acetone, while overestimating ethane emission factors

Three decades of global methane sources and sinks

Methane is an important greenhouse gas, responsible for about 20 of the warming induced by long-lived greenhouse gases since pre-industrial times. By reacting with hydroxyl radicals, methane reduces the oxidizing capacity of the atmosphere and generates ozone in the troposphere. Although most sources and sinks of methane have been identified, their relative contributions to atmospheric methane levels are highly uncertain. As such, the factors responsible for the observed stabilization of atmospheric methane levels in the early 2000s, and the renewed rise after 2006, remain unclear. Here, we construct decadal budgets for methane sources and sinks between 1980 and 2010, using a combination of atmospheric measurements and results from chemical transport models, ecosystem models, climate chemistry models and inventories of anthropogenic emissions. The resultant budgets suggest that data-driven approaches and ecosystem models overestimate total natural emissions. We build three contrasting emission scenarios � which differ in fossil fuel and microbial emissions � to explain the decadal variability in atmospheric methane levels detected, here and in previous studies, since 1985. Although uncertainties in emission trends do not allow definitive conclusions to be drawn, we show that the observed stabilization of methane levels between 1999 and 2006 can potentially be explained by decreasing-to-stable fossil fuel emissions, combined with stable-to-increasing microbial emissions. We show that a rise in natural wetland emissions and fossil fuel emissions probably accounts for the renewed increase in global methane levels after 2006, although the relative contribution of these two sources remains uncertain