Assessing Evapotranspiration Estimates from the Global Soil Wetness Project Phase 2 (GSWP-2) Simulations

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/).We assess the simulations of global-scale evapotranspiration from the Global Soil Wetness Project Phase 2 (GSWP-2) within a global water-budget framework. The scatter in the GSWP-2 global evapotranspiration estimates from various land surface models can constrain the global, annual water budget fluxes to within ±2.5%, and by using estimates of global precipitation, the residual ocean evaporation estimate falls within the range of other independently derived bulk estimates. However, the GSWP-2 scatter cannot entirely explain the imbalance of the annual fluxes from a modern-era, observationally-based global water budget assessment, and inconsistencies in the magnitude and timing of seasonal variations between the global water budget terms are found. Inter-model inconsistencies in evapotranspiration are largest for high latitude inter-annual variability as well as for inter-seasonal variations in the tropics, and analyses with field-scale data also highlights model disparity at estimating evapotranspiration in high latitude regions. Analyses of the sensitivity simulations that replace uncertain forcings (i.e. radiation, precipitation, and meteorological variables) indicate that global (land) evapotranspiration is slightly more sensitive to precipitation than net radiation perturbations, and the majority of the GSWP-2 models, at a global scale, fall in a marginally moisture-limited evaporative condition. Finally, the range of global evapotranspiration estimates among the models is larger than any bias caused by uncertainties in the GSWP-2 atmospheric forcing, indicating that model structure plays a more important role toward improving global land evaporation estimates (as opposed to improved atmospheric forcing).NASA Energy and Water-cycle Study (NEWS, grant #NNX06AC30A), under the NEWS Science and Integration Team activities

A Meating of the Minds: Possible Pitfalls and Benefits of Certified Organic Livestock Production and the Prodigious Potential of Brazil

Certified organic food represents the fastest growing segment of food production in both the United States and throughout the entire world. This article examines the issues and opportunities facing both large and small-scale farmers who wish to engage in organic livestock production. Organic regulations cover everything involved in production, starting with the organic certification process and concluding with slaughter and the subsequent shipping and sale of the end organic product. The final section of this article addresses the unique ability of Brazil - described alternatively as the world\u27s warehouse and the world\u27s [future] source of food - to increase the economic prosperity of its burgeoning farming industry by capitalizing on the world\u27s current organics craze. The conclusion focuses on suggestions for both public and private entities to aid in the continued development of the Brazilian organic livestock industry. Many suggestions also prove applicable to other less developed Latin America countries

A Healthy Diet of Preemption: The Power of the FDA and the Battle Over Restricting High Fructose Corn Syrup From Food and Beverages Labeled \u27Natural\u27

America is unhealthy. America faces an obesity epidemic. The food consumed by Americans is making them fat. Americans, bombarded every single day by negative headlines like these, are becoming more and more health conscious. This newfound commitment to health is reflected in the food and beverages Americans purchase

The Association of Large-Scale Climate Variability and Teleconnections on Wind Energy Resource over Europe and its Intermittency

In times of increasing importance of wind power in the world’s energy mix, this study focuses on a better understanding of the influences of large-scale climate variability on wind power resource over Europe. The impact of the North Atlantic Oscillation (NAO), the Arctic Oscillation (AO), the El Niño Southern Oscillation (ENSO) and the Atlantic Multidecadal Oscillation (AMO) are investigated in terms of their correlation with wind power density (WPD) at 80 m hub height. These WPDs are calculated based on the MERRA Reanalysis data set covering 31 years of measurements. Not surprisingly, AO and NAO are highly correlated with the time series of WPD. This correlation can also be found in the first principal component of a Principal Component Analysis (PCA) of WPD over Europe explaining 14% of the overall variation. Further, cross-correlation analyses indicates the strongest associated variations are achieved with AO/NAO leading WPD by at most one day. Furthermore, the impact of high and low phases of the respective oscillations has been assessed to provide a more comprehensive illustration. The fraction of WPD for high and low AO/NAO increases considerably for northern Europe, whereas the opposite pattern can be observed for southern Europe. Similar results are obtained by calculating the energy output of three hypothetical wind turbines for every grid point over Europe. Thus, we identified a high interconnection potential between wind farms in order to reduce intermittency, one of the primary challenges in wind power generation. In addition, we observe significant correlations between WPD and AMO

Regional climate change of the greater Zambezi River Basin: a hybrid assessment

Projections of regional changes in surface-air temperature and precipitation, in response to unconstrained emissions as well as a climate mitigation policy, for the Zambezi River Basin (ZRB) are presented. These projections are cast in a probabilistic context through a hybrid technique that combines the projections of the MIT Integrated Global System Model (IGSM) to pattern-change kernels from climate-model results of the Coupled Model Intercomparison Project (CMIP). Distributional changes of precipitation and surface-air temperature averaged over the western and eastern ZRB are considered. Overall, the most significant response to climate policy is seen in the spring. Frequency distributions of precipitation change for the unconstrained emission scenario indicate a majority of the outcomes to be drier by 2050, although the distribution spans both increased and decreased precipitation. Through climate policy, the distributions’ total range of outcomes collapses considerably, and perhaps more importantly, the mode of the distribution aligns with zero precipitation change. For surface-air temperature, climate policy consistently reduces the modal value of warming, and this reduction is strongest for the western ZRB. Climate policy also considerably abates the occurrence of the most extreme temperature increases, but the minimum warming in the distributions is less affected.United Nations University. World Institute for Development Economics ResearchMassachusetts Institute of Technology. Joint Program on the Science & Policy of Global Chang

Impacts of Land Use and Biofuels Policy on Climate: Temperature and Localized Impacts

http://globalchange.mit.edu/research/publications/reportsThe impact on climate of future land use and energy policy scenarios is explored using two landuse frameworks: (i) Pure Cost Conversion Response (PCCR), or 'extensification', where the price of land is the only constraint to convert land to agricultural production, including growing biofuels, and (ii) Observed Land Supply Response (OLSR), or 'intensification', where legal, environmental and other constraints encourage more intense use of existing managed land. These two land-use frameworks, involving different economic assumptions, were used to explore how the large-scale plantation of cellulosic biofuels to meet global energy demand impacts the future climate. The land cover of the Community Atmospheric Model Version 3.0 (CAM3.0) was manipulated to reflect these two different land use and energy scenarios (i.e. biofuels and no biofuels). Using these landscapes, present and future climate conditions were simulated to assess the land cover impact. In both the intensification and extensification scenarios, the biofuel energy policy increases the land reflectivity of many areas of the globe, indicating that biofuel cropland is replacing darker land-vegetation, which directly leads to cooling. Moreover, the extensification framework—which involves more deforestation than the intensification framework—leads to larger increases in the reflectivity of the Earth's surface and thus a stronger cooling of the land surface in the extratropics. However, the deforestation which occurred in the tropics produced an increase in temperature due to a decrease in evaporative cooling and cloud cover, and an increase in insolation and sensible heating of the near surface. Nevertheless, these surface-air temperature changes associated with land use are smaller than the effect from changes in the trace-gas forcing (i.e. the enhanced greenhouse effect), although over some regions the land-use change can be large enough to counteract the human-induced, radiatively forced warming. A comparison of these biogeophysical impacts on climate of the land use and biofuel policies with the previously published biogeochemical impact of biofuels indicates the dominance of biogeophysical impacts at 2050.This research is funded by a grant from the USA Department of Energy. The authors gratefully acknowledge the financial support for this work provided by the MIT Joint Program on the Science and Policy of Global Change through a number of Federal agencies and industrial sponsors (for the complete list see http://globalchange.mit.edu/sponsors/current.html)

A Global Land System Framework for Integrated Climate-Change Assessments

Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/).Land ecosystems play a major role in the global cycles of energy, water, carbon and nutrients. A Global Land System (GLS) framework has been developed for the Integrated Global Systems Model Version 2 (IGSM2) to simulate the coupled biogeophysics and biogeochemistry of these ecosystems, as well as the interactions of these terrestrial processes with the climate system. The GLS framework has resolved a number of water and energy cycling deficiencies and inconsistencies introduced in IGSM1. In addition, a new representation of global land cover and classification as well as soil characteristics has been employed that ensures a consistent description of the global land surface amongst all the land components of the IGSM2. Under this new land cover classification system, GLS is run for a mosaic of land cover types within a latitudinal band defined by the IGSM2 atmosphere dynamics and chemistry sub-model. The GLS shows notable improvements in the representation of land fluxes and states of water and energy over the previous treatment of land processes in the IGSM1. In addition, the zonal features of simulated carbon fluxes as well as key trace gas emissions of methane and nitrous oxide are comparable to estimates based on higher resolution models constrained by observed climate forcing. Given this, the GLS framework represents a key advance in the ability of the IGSM to faithfully represent coupled terrestrial processes to the climate system, and is well poised to support more robust two-way feedbacks of natural and managed hydrologic and ecologic systems with the climate and socio-economic components of the IGSM2.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

The Potential Wind Power Resource in Australia: A New Perspective

Australia’s wind resource is considered to be very good, and the utilization of this renewable energy resource is increasing rapidly: wind power installed capacity increased by 35% from 2006 to 2011 and is predicted to account for over 12% of Australia’s electricity generation in 2030. Due to this growth in the utilization of the wind resource and the increasing importance of wind power in Australia’s energy mix, this study sets out to analyze and interpret the nature of Australia’s wind resources using robust metrics of the abundance, variability and intermittency of wind power density, and analyzes the variation of these characteristics with current and potential wind turbine hub heights. We also assess the extent to which wind intermittency, on hourly or greater timescales, can potentially be mitigated by the aggregation of geographically dispersed wind farms, and in so doing, lessen the severe impact on wind power economic viability of long lulls in wind and power generated. Our results suggest that over much of Australia, areas that have high wind intermittency coincide with large expanses in which the aggregation of turbine output does not mitigate variability. These areas are also geographically remote, some are disconnected from the east coast’s electricity grid and large population centers, which are factors that could decrease the potential economic viability of wind farms in these locations. However, on the eastern seaboard, even though the wind resource is weaker, it is less variable, much closer to large population centers, and there exists more potential to mitigate it’s intermittency through aggregation. This study forms a necessary precursor to the analysis of the impact of large-scale circulations and oscillations on the wind resource at the mesoscale.Massachusetts Institute of Technology. Joint Program on the Science & Policy of Global Chang

Adaptation Advantage to Climate Change Impacts on Road Infrastructure in Africa through 2100

The African continent is facing the potential of a US$183.6 billion liability to repair and maintain roads damaged from temperature and precipitation changes related to climate change through 2100. As detailed, the central part of the continent faces the greatest impact from climate change with countries facing an average cost of US$22 million annually, if they adopt a proactive adaptation policy and a US$54 million annual average, if a reactive approach is adopted. Additionally, countries face an average loss of opportunity to expand road networks from a low of 22 per cent to a high of 235 per cent in the central region.infrastructure, climate change, roads, cost estimates

The Potential Wind Power Resource in Australia: A New Perspective

Australia is considered to have very good wind resources, and the utilization of this renewable energy resource is increasing. Wind power installed capacity increased by 35% from 2006 to 2011 and is predicted to account for over 12% of Australia’s electricity generation in 2030. This study uses a recently published methodology to address the limitations of previous wind resource analyses, and frames the nature of Australia’s wind resources from the perspective of economic viability, using robust metrics of the abundance, variability and intermittency of wind power density, and analyzes whether these differ with higher wind turbine hub heights. We also assess the extent to which wind intermittency can potentially be mitigated by the aggregation of geographically dispersed wind farms. Our results suggest that over much of Australia, areas that have high wind intermittency coincide with large expanses in which the aggregation of turbine output does not mitigate variability. These areas are also geographically remote, some are disconnected from the east coast’s electricity grid and large population centers, and often are not connected or located near enough to high capacity electricity infrastructure, all of which would decrease the potential economic viability of wind farms in these locations. However, on the eastern seaboard, even though the wind resource is weaker, it is less variable, much closer to large population centers, and there exists more potential to mitigate its intermittency through aggregation.The authors gratefully acknowledge the financial support for this work provided by the MIT Joint Program on the Science and Policy of Global Change through a number of federal agencies and industrial sponsors including US Department of Energy grant DE-FG02-94ER61937