Browsing by Author "Cassidy, Emily"

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    The Impact of Diet Preference on Agricultural Productivity and the Environment
    (2013-11) Cassidy, Emily
    Worldwide demand for crops is increasing rapidly due to global population growth, increased biofuel production, and changing dietary preferences. Meeting these growing demands will be a substantial challenge that will tax the capability of our food system and prompt calls to dramatically boost global crop production. However, to increase food availability, we may also consider how the world's crops are allocated to different uses and whether it is possible to feed more people with current levels of crop production. Of particular interest are the uses of crops as animal feed and as biofuel feedstocks. We find that, given the current mix of crop uses, growing food exclusively for direct human consumption could, in principle, increase available food calories by as much as 70%, which could feed an additional 4 billion people (more than the projected 2-3 billion people arriving through population growth). Even small shifts in our allocation of crops to animal feed and biofuels could significantly increase global food availability, and could be an instrumental tool in meeting the challenges of ensuring global food security. We also illustrate how shifting even slightly away from beef and pork can reduce environmental impact by reducing the water footprints and greenhouse gas emissions associated with diets.
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    Modeling the Response of Arctic Vegetation to Increasing Atmospheric Carbon Dioxide and Climate Change
    (2009-10-07) Cassidy, Emily
    An increase in atmospheric carbon dioxide is contributing to planetary warming that is strongest over high latitude land areas of the Northern Hemisphere. Elevated levels of atmospheric carbon dioxide and strong warming have led to changes in vegetation distribution, permafrost depth, and snow cover, which significantly affect the interactions between terrestrial ecosystems and the climate through biophysical and biogeochemical processes. With a continued rise in greenhouse gas emissions and additional warming in the high latitudes, uncertainty exists as to how the Arctic biosphere will respond in the coming decades and whether Arctic ecosystems will remain a carbon sink or instead become a source of carbon to the atmosphere. Elevated carbon dioxide and climate change can affect vegetation growth through changing the assimilation of carbon dioxide and the respiration of carbon from the vegetation and soil. Using a dynamic global vegetation model (IBIS), potential changes in both the biophysical and biogeochemical processes of Arctic vegetation were analyzed to determine how future climate change and elevated atmospheric carbon dioxide may alter their functioning and ability to store carbon.