Rubin's research focuses on using economic mechanisms (tradable credits, taxes, regulation design) and information programs to assist with the attainment of environmental goals. Recent publications investigate the economic and environmental impacts from trading greenhouse gases and fuel efficiency credits for automobiles and light-duty trucks. His research also investigates the economics of alternative transportation fuels and vehicles in the United States which can have substantial climate impacts. He is particularly interested in transitional paths and the introduction of new technologies.
The use of flexible economic mechanisms to control criteria pollutants and emissions of global warming gasses is now widely accepted as environmentally sound as well as cost-effective. Tradable CO2 credits are an essential part of the European Union's Emission Trading System for CO2 and in the Regional Greenhouse Gas Initiative, in which Maine and other Northeastern states have agreed to cut CO2 emissions from electric power plants 10% below current levels. Research by Rubin and his co-authors has shown the importance of the design of trading systems both in terms of attaining expected environmental benefits and in terms of the costs to society of attaining given reduction targets. Particularly important for the reduction of long-term global pollutants such as CO2, is the intertemporal timing of emissions. Given a non-optimal negotiated emission reduction path, society can lower net costs by adjusting the ratio of trading CO2 credits across time to one that better reflects costs to businesses and society.
One of our research efforts focused on developing a model to forecast emissions of CO2 from Maine under various economic scenarios during the period 1990 to 2020 (Cronan et al. 2000). Beginning with baseline 1990 emissions of 19.6 million tons of carbon dioxide equivalents (CDE) from the State of Maine, the model examined how changes in energy demand, economic activity, transportation growth, and fuel mix would potentially affect annual emissions of CO2 from residential, commercial, industrial, transportation, and utility sectors in Maine. Model simulations indicated that under the most conservative emissions forecasting scenario, CO2 emissions were expected to increase 14% from 1990 to 2005 and a total of 25% from 1990 to 2020. In the worst case scenario examined with the model, CO2 emissions were projected to increase 38% from 1990 to 2005 and a total of 68% from 1990 to 2020. With more recent data becoming available, we are planning to re-visit the model to see which of the forecasts from 1990-2005 best approximates the observed trends for CO2 emissions in Maine.
A second research effort focuses on quantifying nutrient transfer fluxes from the major Maine river basins to the Gulf of Maine. These baseline estimates of carbon and nitrogen fluxes in the Penobscot, Kennebec, and Androscoggin River basins will provide baseline reference conditions that will permit future detection of changes associated with climate change impacts in the Maine landscape. One of the ways in which Maine watersheds may respond to climate changes is through adjustments in biogeochemical cycling and export fluxes as the systems encounter new thermal and moisture regimes of the future.
Climate change is quickly climbing the ranks as a major factor of concern in the fate of species, communities and ecosystems. Paleontology has taught us that climate change in the past has often resulted in dramatic changes in the life forms occupying various regions due its effects on extinctions, changes in species ranges and evolution of the species themselves. Crude models of the influence of future climate change suggest losses exceeding a third of all species from some regions in the next 50-100 years, with particularly conspicuous reductions of many of the socially or economically important groups that we often cherish, such as large mammals or cold water fishes. Analogous projections for changes in species ranges or their evolutionary potential are less clear and it is even possible that some species, including nuisance species, might flourish. What is clear, however, is that building a working knowledge of the ways that organisms will respond to climate change is essential if we are to facilitate conservation of those species or make plans to cope with changes in the distribution, abundance or features of the species that we rely upon.
Theoretical, laboratory and field research at the University of Maine is exploring these issues in an array of study systems ranging from the lakes, rivers and woods of Maine to the forests and streams of the tropics. Researchers working on migration in fishes, birds and other animals that visit Maine or move about habitats within the state are learning how changes in seasonal resources or conditions might break the links in those migratory life cycles or reduce the viable habitat for such species. Studies of rare or threatened species at the edge of their range in Maine (e.g., Canada Lynx, Atlantic salmon, freshwater mussels, shortnose sturgeon), provide insights into climatic threats to some of the state's most sensitive, and yet iconic species. Work on invasions of plants and animals are providing a window into the possible future species composition of Maine's woods and waters as a result of the combined effects of climate change and human introductions. Research on the ability of species to evolve on the time scale of years to decades is being adapted to new conservation strategies and to explaining how some species might extend their ranges or become problematic invaders.
Conservation biology in the face of climate change poses new challenges and a new path of discovery, but researchers at the University of Maine are combining applied approaches with cutting edge theory and experimentation to help us down that road in both the near and distant future.