Author: David Haim

Publisher:

Published: 2011

Total Pages: 136

ISBN-13:

This dissertation's three essays explore the effects of climate change on land use changes in the U.S., how future land areas in all major land uses change by projecting land use at the regional scale under two IPCC climate change scenarios. Investigate how and what role should carbon sequestration plays as a mitigation strategy given uncertainty of climate impacts and, estimate how responsive the demand for and the supply of urban land is to changes in its price and how different climatic variables effect both the supply and the demand for urban land. The first essay uses an econometric model to project regional and national landuse changes in the U.S. under two IPCC climate change scenarios. The key driver of land-use change in the model is county-level measures of net returns to five major land uses. The net returns are modified for the IPCC scenarios according to assumed trends in population and income and projections from integrated assessment models of agricultural prices and agricultural and forestry yields. For both scenarios, we project large increases in urban land by the middle of the century, while the largest declines are in cropland area. Significant differences among regions in the projected patterns of land-use change are evident, including an expansion of forests in the Mountain and Plains regions with declines elsewhere. Comparisons to projections with no climate change effects on prices and yields reveal relatively small differences. Thus, our findings suggest that future land use patterns in the U.S. will be shaped largely by urbanization, with climate change having a relatively small influence. The second essay explores the optimal time path of carbon sequestration and carbon abatement in stabilizing CO2 levels under uncertainty of climate impacts. We question the conventional wisdom that carbon sequestration should be used as a near term strategy by recognizing the fact that sequestration, unlike abatement, can actually remove CO2 from the atmosphere. Two related models are examined: a deterministic fixed end point and finite time horizon model and a two-period sequential decision making model. In the latter, uncertainty regard the stabilization level of the atmospheric stock is resolved prior to the decision on how much to control the stock in the second period. Present value costs of abatement and sequestration are minimized subject to two state variables; the level of CO2 stock in the atmosphere and the stock of suitable land that can be converted to forestland. Both models show that carbon sequestration may play an important role in climate change mitigation under certain conditions. In addition, the stochastic model finds that an increase in the variability of climate impacts results in higher rates of abatement today while leaving some sequestration capacity as a safety value for the future. In the third essay, a structural model of the demand for and the supply of urban land is estimated using panel data on 3032 counties in the contiguous U.S for the four time periods 1982, 1987, 1992 and, 1997. A two-step estimation procedure is applied. In the first step, fixed effects and time-varying variables are used to estimate the structural system of demand and supply equations via Two-Stage Least Squares (2SLS) procedure. This yields consistent estimates of the structural equations' parameters. The model is then extended to a hierarchical linear model. The contribution of observed time-invariant variables in explaining counties fixed effects is investigated. Among these variables are climatic and geographical variables that are assumed to affect both the supply and the demand for urban land, though in potentially different ways. Results suggest inelastic supply and demand at the national and regional levels with the exception of an elastic demand in the West region. Examined climatic and geographical variables are found to have significant effects on both the supply of and the demand for urban land.