The role of natural variability in projections of climate change impacts on U.S. ozone pollution

Climate change can impact air quality by altering the atmospheric conditions that determine pollutant concentrations. Over large regions of the U.S., projected changes in climate are expected to favor formation of ground-level ozone and aggravate associated health effects. However, modeling studies exploring air quality-climate interactions have often overlooked the role of natural variability, a major source of uncertainty in projections. Here we use the largest ensemble simulation of climate-induced changes in air quality generated to date to assess its influence on estimates of climate change impacts on U.S. ozone. We find that natural variability can significantly alter the robustness of projections of the future climate's effect on ozone pollution. In this study, a 15 year simulation length minimum is required to identify a distinct anthropogenic-forced signal. Therefore, we suggest that studies assessing air quality impacts use multidecadal simulations or initial condition ensembles. With natural variability, impacts attributable to climate may be difficult to discern before midcentury or under stabilization scenarios

Measuring Welfare Loss Caused by Air Pollution in Europe: A CGE Analysis

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).To evaluate the socio-economic impacts of air pollution, we develop an integrated approach based on computable general equilibrium (CGE). Applying our approach to Europe shows that even there, where air quality is relatively high compared with other parts of the world, health-related damages caused by air pollution are substantial. We estimate that in 2005, air pollution in Europe caused a consumption loss of around 220 billion Euro (year 2000 prices, around 3 percent of consumption level) and a social welfare loss of around 370 billion Euro, measured as the sum of lost consumption and leisure (around 2 percent of welfare level). In addition, we estimated that a set of 2020-targeting air quality improvement policy scenarios, which are proposed in the 2005 CAFE program, would bring 18 European countries as a whole a welfare gain of 37 to 49 billion Euro (year 2000 prices) in year 2020 alone.This study received support from the MIT Joint Program on the Science and Policy of Global Change, which is funded by a consortium of government, industry and foundation sponsors

Taking Action to Reduce Waste: Quantifying Impacts of Model Use in a Multiorganizational Sustainability Negotiation

We use a role-play simulation to examine how using quantitative models influences the process and outcome of sustainability negotiations. Our experimental approach involved 74 teams of five parties negotiating the details of a pilot test to compost and/or recycle used paper coffee cups. Approximately half of these negotiation teams were given a quantitative model—a life cycle assessment (LCA). We measured both negotiation process and outcome variables, in particular identifying favorable agreements—the mutually exclusive set of agreements that either minimized carbon dioxide emissions or maximized the parties’ collective earned value. We found that most teams used a quantitative model; nearly half of those cocreated their own while negotiating. In our sample, teams that used a model, even those cocreating the model while negotiating, reached agreement more quickly than teams not using a model. Teams that cocreated the LCA reached a higher number of favorable agreements. We observed two dominant manners of model use: using the model to test alternatives while developing an agreement and verifying that a tentative agreement would sufficiently reduce carbon dioxide emissions. We conclude that using a quantitative model during a sustainability negotiation can help to increase the chances of obtaining a favorable agreement without lengthening the negotiation duration.Starbucks Coffee Compan

Seasonal and Spatial Patterns of Mercury Wet Deposition in the United States: Constraints on the Contribution from North American Anthropogenic Sources

Observed wet deposition fluxes of mercury in the United States show a maximum in the Southeast, and a consistent seasonal variation (maximum in summer, minimum in winter) that increases in amplitude from north to south. We simulate these patterns successfully with a global 3-D chemical transport model (GEOS-Chem) including our best estimates of sources and processes. We attribute the high wet deposition over the Southeast in summer to scavenging of upper-altitude Hg(II) by deep convection. Seasonal variation at higher latitudes is attributed to a combination of enhanced summertime oxidation of Hg(0) and inefficient scavenging of Hg(II) by snow. Scavenging of Hg(II) from above the boundary layer contributes over half of wet deposition to the US in the model. Even within the boundary layer, we find that most of Hg(II) originates from the global mercury pool. Wet deposition in the model accounts for only 30% of total mercury deposition in the US, the remainder being from dry deposition, including 42% from Hg(0) uptake. North American anthropogenic emissions contribute 20% of total mercury deposition in the US (up to 50% in the industrial Midwest and Northeast).Earth and Planetary SciencesEngineering and Applied Science

The Mercury Game: Evaluating a Negotiation Simulation that Teaches Students about Science–Policy Interactions

Environmental negotiations and policy decisions take place at the science–policy interface. While this is well known in academic literature, it is often difficult to convey how science and policy interact to students in environmental studies and sciences courses. We argue that negotiation simulations, as an experiential learning tool, are one effective way to teach students about how science and policy interact in decision-making. We developed a negotiation simulation, called the Mercury Game, based on the global mercury treaty negotiations. To evaluate the game, we conducted surveys before and after the game was played in university classrooms across North America. For science students, the simulation communicates how politics and economics affect environmental negotiations. For environmental studies and policy students, the mercury simulation demonstrates how scientific uncertainty can affect decision-making. Using the mercury game as an education tool allows students to learn about complex interactions between science and society and develop communication skills.This research was funded by the U.S. National Science Foundation (#1053648)

Using built-in functions of Adobe Acrobat Pro DC to help the selection process in systematic review of randomized trials

This letter describes a simple way of using Adobe Acrobat Pro DC to help select and auto-extract data from Portable Document Format (PDFs) of randomised trials in order to assist swift early selection of trials for a systematic revie

Splitting the South: China and India’s Divergence in International Environmental Negotiations

International environmental negotiations often involve conflicts between developed and developing countries. However, considering environmental cooperation in a North-South dichotomy obscures important variation within the Global South, particularly as emerging economies become more important politically, economically, and environmentally. This article examines change in the Southern coalition in environmental negotiations, using the recently concluded Minamata Convention on Mercury as its primary case. Focusing on India and China, we argue that three key factors explain divergence in their positions as the negotiations progressed: domestic resources and regulatory politics, development constraints, and domestic scientific and technological capacity. We conclude that the intersection between scientific and technological development and domestic policy is of increasing importance in shaping emerging economies’ engagement in international environmental negotiations. We also discuss how this divergence is affecting international environmental cooperation on other issues, including the ozone and climate negotiations