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Climate change in the circumpolar region is causing dramatic environmental change that is increasing the vulnerability of infrastructure. We quantified the economic impacts of climate change on Alaska public infrastructure under relatively high and low climate forcing scenarios [representative concentration pathway 8.5 (RCP8.5) and RCP4.5] using an infrastructure model modified to account for unique climate impacts at northern latitudes, including near-surface permafrost thaw. Additionally, we evaluated how proactive adaptation influenced economic impacts on select infrastructure types and developed first-order estimates of potential land losses associated with coastal erosion and lengthening of the coastal ice-free season for 12 communities. Cumulative estimated expenses from climate-related damage to infrastructure without adaptation measures (hereafter damages) from 2015 to 2099 totaled $5.5 billion (2015 dollars, 3% discount) for RCP8.5 and $4.2 billion for RCP4.5, suggesting that reducing greenhouse gas emissions could lessen damages by $1.3 billion this century. The distribution of damages varied across the state, with the largest damages projected for the interior and southcentral Alaska. The largest source of damages was road flooding caused by increased precipitation followed by damages to buildings associated with near-surface permafrost thaw. Smaller damages were observed for airports, railroads, and pipelines. Proactive adaptation reduced total projected cumulative expenditures to $2.9 billion for RCP8.5 and $2.3 billion for RCP4.5. For road flooding, adaptation provided an annual savings of 80-100% across four study eras. For nearly all infrastructure types and time periods evaluated, damages and adaptation costs were larger for RCP8.5 than RCP4.5. Estimated coastal erosion losses were also larger for RCP8.5.Alaska | climate change | damages | adaptation | infrastructure

Bulk expansion of the anode upon oxidation is considered to be responsible for the lack of redox stability in high-temperature solid oxide fuel cells ͑SOFCs͒. The bulk expansion of nickel-yttria stabilized zirconia ͑YSZ͒ anode materials was measured by dilatometry as a function of sample geometry, ceramic component, temperature, and temperature cycling. The strength of the ceramic network and the degree of Ni redistribution appeared to be key parameters of the redox behavior. A model of the redox mechanism in nickel-YSZ anodes was developed based on the dilatometry data and macro-and microstructural observations.

a b s t r a c tThis analysis reports on the projected cost of Alaska's public infrastructure at risk from rapid climate change. Specifically, we coupled projections of future climate with engineering rules of thumb to estimate how thawing permafrost, increased flooding, and increased coastal erosion affect annualized replacement costs for nearly 16,000 structures. We conclude that climate change could add $3.6-$6.1 billion (+10% to +20% above normal wear and tear) to future costs for public infrastructure from now to 2030 and $5.6-$7.6 billion (+10% to +12%) from now to 2080. These estimates take into account different possible levels of climate change and assume agencies strategically adapt infrastructure to changing conditions. In addition to implementing a risk-based economic analysis of climate change impacts, this research effort demonstrates that implementing plausible adaptation strategies could offset impacts by up to 45% over the long-run.

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To estimate the economic effects of weather variability in the United States, the authors define and measure weather sensitivity as the variability in economic output that is attributable to weather variability, accounting for changes in technology and changes in levels of economic inputs (i.e., capital, labor, and energy). Using 24 yr of economic data and weather observations, quantitative models of the relationship between state-level sectoral economic output and weather variability are developed for the 11 nongovernmental sectors of the U.S. economy; temperature and precipitation measures were used as proxies for all weather impacts. All 11 sectors are found to have statistically significant sensitivity to weather variability. Economic inputs were then constant and economic output was estimated in the 11 estimated sector models, varying the weather inputs only using 70 yr of historic weather observations. It was found that U.S. economic output varies by up to $485 billion yr−1 of 2008 gross domestic product, about 3.4%, owing to weather variability. U.S. states that are more sensitive to weather variability are identified and sectors are ranked by their degree of weather sensitivity. This work illustrates a valid approach to measuring the economic impact of weather variability, gives baseline information and methods for more detailed studies of the sensitivity of each sector to weather variability, and lays the groundwork for assessing the value of current or improved weather forecast information given the economic impacts of weather variability.

The most commonly used anode in development of solid oxide fuel cells (SOFCs) is currently a Ni/yttria-stabilized zirconia (YSZ) cermet. 1 Despite excellent properties for operation in hydrogen, the Nibased anode suffers from some disadvantages related to volume instability upon redox cycling and detrimental carbon formation caused by cracking of methane during operation in dry natural gas. For mixtures of CH 4 and H 2 O the catalytic properties of Ni cause total conversion over the first few millimeters of a cell. The endothermic nature of the steam reforming process can thus cause steep thermal gradients potentially capable of mechanically damaging the cell stack. 2 The basic requirements for an SOFC anode are as follows. 1. Electrochemical ability to oxidize methane directly without deposition of carbon, or alternatively adequate catalytic properties for steam reforming combined with the ability to oxidize H 2 and CO.2. Adequate electronic conductivity and preferably also oxide-ion conductivity to enhance electrode efficiency.3. Physical and chemical stability in oxidizing and reducing atmospheres, and chemical compatibility with the electrolyte during production and operation. 4. A thermal expansion coefficient (TEC) value comparable with that of the supporting element of the cell.Lanthanum-chromite (LC)-based materials have previously been investigated primarily as interconnect material, where typical dopants are Ca (LCC) and Sr (LSC). However, this group of materials may also be considered for use as anode material. The aim of this work has been to examine to which extent selected doped LC materials fulfill the listed requirements for anodes, and to which extent the problems faced with Ni/YSZ electrodes can be avoided. Key properties of selected LC materials are reviewed in the following.Electrochemical and catalytic properties.-Experiments reported in literature indicate little or no reforming activity or direct oxidation of CH 4 on lanthanum chromites, 3-7 disregarding experiments where a catalytic active current collector such as Pt has been applied. 8,9 Considering this, addition of a steam reforming catalyst to the LC electrode might be required. 4,7 Dissociation (cracking) of dry CH 4 occurs on LC materials at temperatures of 800 to 900ЊC, 5 but can apparently be avoided by addition of small amounts of water. 7 Preferably the reforming step should take place internally near the anode, where (i) water is evolved by the anode reaction and therefore does not have to be added or recycled, and (ii) heat for the endothermic steam reforming reaction is available from ohmic losses in the fuel cell during operation.Conductivity.-The electronic conductivity of LC is enhanced by the use of divalent doping on either A or B sites in the perovskite lattice. At high pO 2 , the charge balance is maintained by the formation of Cr 4ϩ . However, when the material is exposed to reducing conditions, the lattice looses oxygen, oxygen vacancies are formed, and the charge balance is now attained by reduction of Cr 4ϩ to Cr 3...

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