世界経済・社会統計 = World development indicators

Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

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Climate Change 2007: The Physical Science Basis.

Impatti, adattamento e vulnerabilita Le cause e le responsabilita dei cambiamenti climatici sono state trattate sul numero di ottobre della rivista Cda. Approfondiamo l’argomento presentando il documento: “Cambiamenti climatici 2007: impatti, adattamento e vulnerabilita” votato ad aprile 2007 dal secondo gruppo di lavoro del Comitato Intergovernativo sui Cambiamenti Climatici (Intergovernmental Panel on Climate Change). Si tratta del secondo di tre documenti che compongono il quarto rapporto sui cambiamenti climatici.

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Climate Change 2007: Impacts, Adaptation and Vulnerability.

Efforts to anticipate how climate change will affect future food availability can benefit from understanding the impacts of changes to date. We found that in the cropping regions and growing seasons of most countries, with the important exception of the United States, temperature trends from 1980 to 2008 exceeded one standard deviation of historic year-to-year variability. Models that link yields of the four largest commodity crops to weather indicate that global maize and wheat production declined by 3.8 and 5.5%, respectively, relative to a counterfactual without climate trends. For soybeans and rice, winners and losers largely balanced out. Climate trends were large enough in some countries to offset a significant portion of the increases in average yields that arose from technology, carbon dioxide fertilization, and other factors.

https://science.sciencemag.org/content/sci/early/2011/05/04/science.1204531.full.pdf

Climate Trends and Global Crop Production Since 1980

The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.

Climate change 2014 - Mitigation of climate change

In the context of impacts research, detection and attribution exercises evaluate whether aspects of human and natural systems are changing in response to the impetus of climate change. Concepts and methods for detection and attribution have been established in the physical science community, evaluating changes in the climate system due to anthropogenic forcing. In contrast, a conceptual framework for detection and attribution of climate change impacts that is consistent and applicable across disciplines is still lacking. In an attempt to overcome this methodological deficit, this paper outlines the major challenges involved in and provides workable definitions of detection and attribution in the context of impacts. Reaching beyond the current focus of the literature on hydrology and ecological effects, it sets a focus on challenges that are inherent in the particular dynamics of human and managed systems, including non-stationary baseline behaviour, multiple drivers, and active adaptation.

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Detection and attribution of climate change impacts - is a universal discipline possible?

This year produced much new evidence that the observed and anticipated impacts from human-caused climate change are bigger than previously thought. The release of a new report by the United Nations’ Intergovernmental Panel on Climate Change made this point quite clearly by synthesizing tens of thousands of scientific papers. If you are still wondering whether it is indeed getting warmer, the answer is an unambiguous yes! Figure 1 displays the average measured daily temperature for the state of California, and the upward trend is clear.

Agriculture and the Social Cost of Carbon

This paper examines the consequences of data error in data series used to construct aggregate indicators. Using the most popular indicator of country level economic development, the Human Development Index (HDI), we identify three separate sources of data error. We propose a simple statistical framework to investigate how data error may bias rank assignments and identify two striking consequences for the HDI. First, using the cutoff values used by the United Nations to assign a country as ‘low’, ‘medium’, or ‘high’ developed, we find that currently up to 45% of developing countries are misclassified. Moreover, by replicating prior development/macroeconomic studies, we find that key estimated parameters such as Gini coefficients and speed of convergence measures vary by up to 100% due to data error.

Human Development Index: Are Developing Countries Misclassified? (former title: "Consequences of Data Error in Aggregate Indicators: Evidence from the Human Development Index)

The Clean Air Act has authorized an array of fuel regulations to reduce the precursors to ambient ozone pollution, among other pollutants. With the emergence of stringent fuel regulations for the most pollution-intensive cities, and the opportunity for states to adopt fuel content regulations, the U.S. gasoline market has evolved over the past three decades to address local pollution. We have evaluated the pollutant concentration, emissions, and price impacts of Federal RFG, RVP, California RFG, and other boutique fuel rules. We find that California RFG continues to deliver large improvements in air quality, while the benefits from RFG, RVP and boutique fuels are either small or statistically insignificant. We note, that ex post impacts of reformulated fuels are smaller than those predicted by ex ante analyses.

Localizing Environmental Regulation: The Case of Boutique Fuels

In 2016 natural gas became the United States’ primary source of energy for electricity generation. It is also the main heating fuel for more than 50% of American homes. Hence understanding residential natural gas consumption behavior has become a first-order problem. In this paper, we provide the first ever causally identified, microdata-based estimates of residential natural gas demand elasticities using a decade-long panel of more than 275 million bills in California. To overcome multiple sources of endogeneity, we utilize the border between two major natural-gas utilities, in conjunction with an instrumental variables strategy. We estimate the elasticity of demand for residential natural gas is between 0.31 and 0.17. We also provide evidence of seasonal and income-based heterogeneity in this elasticity. This heterogeneity provides unexplored policy avenues that may be simultaneously efficiency-enhancing and pro-poor. ⇤Corresponding author: Edward Rubin, 207 Giannini Hall #3310, Berkeley, CA. Email: edward@berkeley.edu. Auffhammer: auffhammer@berkeley.edu. We thank the Pacific Gas and Electric Company, the Southern California Gas Company, and San Diego Gas & Electric for making their billing data available. We thank Reed Walker, James Sallee, Meredith Fowlie, Lucas Davis, Severin Borenstein and seminar participants at Berkeley ARE and the Lulea Department of Economics for valuable feedback. All remaining errors are the authors. Please do not cite without permission from the authors.

Maximilian Auffhammer

Papers

Detection and attribution of climate change impacts - is a universal discipline possible?

Agriculture and the Social Cost of Carbon

Human Development Index: Are Developing Countries Misclassified? (former title: "Consequences of Data Error in Aggregate Indicators: Evidence from the Human Development Index)

Localizing Environmental Regulation: The Case of Boutique Fuels

Elasticities, heterogeneity, and optimal cost recovery: Evidence from 300M+ natural gas bills