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Transient Climate Change and Potential Croplands of the World in the 21st Century

A cropland distribution model, which is based on climate, soil and topography, is applied to estimate the area and spatial distribution of global potential croplands under contemporary climate and to assess the effect of transient climate changes projected by the MIT Integrated Global System Model for assessment of climate change. The area of global potential croplands is about 32.91 x 106 km 2 under contemporary climate, and increases substantially over the period of 1977-2100 and differs among the three transient climate change predictions, being about +6.7% (2.20 x 106 km2), +11.5% (3.78 x 106 km2), and +12.5% (4.12 x 106 km2) in 2100, respectively. Among twelve economic regions of the world, the Former Soviet Union and the Other OECD Countries regions have the largest increases in potential croplands, while developing countries have little increases in potential croplands. Spatial distribution of potential croplands changes considerably over time, dependent upon the transient climate change predictions.

Transient Climate Change and Potential Croplands of the World in the 21st Century

A cropland distribution model, which is based on climate, soil and topography, is applied to estimate the area and spatial distribution of global potential croplands under contemporary climate and to assess the effect of transient climate changes projected by the MIT Integrated Global System Model for assessment of climate change. The area of global potential croplands is about 32.91 x 106 km 2 under contemporary climate, and increases substantially over the period of 1977-2100 and differs among the three transient climate change predictions, being about +6.7% (2.20 x 106 km2), +11.5% (3.78 x 106 km2), and +12.5% (4.12 x 10 6 km2) in 2100, respectively. Among twelve economic regions of the world, the Former Soviet Union and the Other OECD Countries regions have the largest increases in potential croplands, while developing countries have little increases in potential croplands. Spatial distribution of potential croplands changes considerably over time, dependent upon the transient climate change predictions.

 

Transportation in a Climate-Constrained World

About the book: In the nineteenth century, horse transportation consumed vast amounts of land for hay production, and the intense traffic and ankle-deep manure created miserable living conditions in urban centers. The introduction of the horseless carriage solved many of these problems but has created others. Today another revolution in transportation seems overdue. Transportation consumes two-thirds of the world's petroleum and has become the largest contributor to global environmental change. Most of this increase in scale can be attributed to the strong desire for personal mobility that comes with economic growth.

In Transportation in a Climate-Constrained World, the authors present the first integrated assessment of the factors affecting greenhouse gas (GHG) emissions from passenger transportation. They examine such topics as past and future travel demand; the influence of personal and business choices on passenger travel's climate impact; technologies and alternative fuels that may become available to mitigate GHG emissions from passenger transport; and policies that would promote their adoption. And most important, taking into account all of these options are taken together, they consider how to achieve a more sustainable transportation system in the next thirty to fifty years.

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Trends in the North Atlantic Carbon Sink: 1992-2006

A biogeochemical general circulation model is used to assess the impact of climate variability from 1992 to 2006 on air-sea CO2 fluxes and ocean surface pCO2 in the North Atlantic and to understand trends in the North Atlantic carbon sink over this time period. The model indicates that the North Atlantic carbon sink increased from the mid-1990s to the mid-2000s. Consistent with observations, the model output indicates large changes in the physical and chemical systems of the basin. An analysis of the changes in dissolved inorganic carbon (DIC), alkalinity (ALK), and sea-surface temperature (SST), combined with model-derived DIC tendency terms, allow for an investigation of the mechanisms that dominate the spatial variability and magnitude of the trends in the air-sea fluxes and pCO2. Modeled parameters compare favorably with available data from the Bermuda Atlantic Time Series in the subtropical gyre and the SURATLANT volunteer observation ship data in the subpolar gyre. Subtropical changes are controlled primarily by changes in sea-surface temperature. Subpolar changes in pCO2 are instead driven dynamically, primarily through changing vertical supply of DIC. The amplitude of the ocean pCO2 and air-sea flux trends are largely related to the increase in atmospheric CO2, but changes to the forcing and circulation of the North Atlantic during this period set the spatial patterns. Model changes are consistent with variation in the North Atlantic Oscillation over the period of study.

Tropical Cyclone-Induced Upper-Ocean Mixing and Climate: Application to Equitable Climates

Tropical cyclones instigate an isolated blast of vigorous mixing in the upper tropical oceans, stirring warm surface water with cooler water in the thermocline. Previous work suggests that the frequency, intensity, and lifetime of these storms may be functions of the climate state, implying that transient tropical mixing could have been stronger during warmer equable climates with higher concentrations of carbon dioxide. Stronger mixing of the tropical oceans can force the oceans’ meridional heat flux to increase, cooling tropical latitudes while warming higher ones. This response differs significantly from previous modeling studies of equable climates that used static mixing; coupling mixing to climate changes the dynamic response. A parameterization of mixing from tropical cyclones is developed, and including it leads to a cooling of tropical oceans and a warming of subtropical waters compared with control cases with fixed mixing. The mixing penetration depth regulates the magnitude of the response.

© 2008 American Meteorological Society

Tropical Cyclones

Tropical cyclones encompass virtually every subdiscipline of geophysical fluid dynamics, including cumulus convection, boundary layers, thermodynamic cycles, surface wave dynamics, upper ocean wind-driven circulations, barotropic instability, Rossby waves, and air-sea interaction. After briefly reviewing what is known about the structure, behavior, and climatology of these fascinating storms, the author provides an overview of their physics, focusing on the unique and poorly understood nature of the air-sea interface, and discusses several of the most interesting avenues of ongoing research.

© 2003 Annual Reviews

Same Science, Differing Policies; The Saga of Global Climate Change

This paper provides a comparative analysis of the economic and political interests influencing the progress of climate negotiation. The primary focus is on the U.S., France, Germany, U.K., Belgium, Netherlands, and the E.U. itself. A discussion of the drivers of policy and differing responses on a national basis is presented to highlight the larger influences at work. The driving factors range across economic and political interests, public concern, bureaucratic goals, scientific evidence, non-governmental organizations, energy industries, and are relevant in each country to varying degrees. Also included is a personal forecast of what can be expected to emerge in the next few months as the current negotiations reach their climax in Kyoto, Japan, in December 1997.

Scenarios with MIT Integrated Global System Model: Significant Global Warming Regardless of Different Approaches

A wide variety of scenarios for future development have played significant roles in climate policy discussions. This paper presents projections of greenhouse gas (GHG) concentrations, sea level rise due to thermal expansion and glacial melt, oceanic acidity, and global mean temperature increases computed with the MIT Integrated Global Systems Model (IGSM) using scenarios for twenty-first century emissions developed by three different groups: intergovernmental (represented by the Intergovernmental Panel on Climate Change), government (represented by the U.S. government Climate Change Science Program) and industry (represented by Royal Dutch Shell plc). In all these scenarios the climate system undergoes substantial changes. By 2100, the CO2 concentration ranges from 470 to 1020 ppm compared to a 2000 level of 365 ppm, the CO2-equivalent concentration of all greenhouse gases ranges from 550 to 1780 ppm in comparison to a 2000 level of 415 ppm, oceanic acidity changes from a current pH of around 8 to a range from 7.63 to 7.91, in comparison to a pH change from a preindustrial level by 0.1 unit. The global mean temperature increases by 1.8 to 7.0?C relative to 2000. Such increases will require considerable adaptation of many human systems and will leave some aspects of the earth’s environment irreversibly changed. Thus, the remarkable aspect of these different approaches to scenario development is not the differences in detail and philosophy but rather the similar picture they paint of a world at risk from climate change even if there is substantial effort to reduce emissions.

© 2010 Springer

Second-Best Instruments for Near-Term Climate Policy: Intensity Targets vs. the Safety Valve

Current proposals for greenhouse gas emissions regulations in the United States mainly take the form of emissions caps with tradable permits. Since Weitzman's (1974) study of prices vs. quantities, economic theory predicts that a price instrument is superior under uncertainty in the case of stock pollutants. Given the general belief in the political infeasibility of a carbon tax in the US, there has been recent interest in two other policy instrument designs: hybrid policies and intensity targets. We extend the Weitzman model to derive an analytical expression for the expected net benefits of a hybrid instrument under uncertainty. We compare this expression to one developed by Newell and Pizer (2006) for an intensity target, and show the theoretical minimum correlation between GDP and emissions required for an intensity target to be preferred over a hybrid. In general, we show that unrealistically high correlations are required for the intensity target to be preferred to a hybrid, making a hybrid a more practical instrument in practice. We test the predictions by performing Monte Carlo simulation on a computable general equilibrium model of the US economy. The results are similar, and we show with the numerical model that when marginal abatement costs are non-linear, an even higher correlation is required for an intensity target to be preferred over a safety valve.

© 2010 Elsevier

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