. R.J. Hobbs; H.A. Mooney.
Journal of Vegetation Science:
. J.W. Hall, R.J. Dawson, S.L. Barr, M. Batty, A.L. Bristow, S. Carney, A. Dagoumas, A. Ford, C. Harpham, M.R. Tight, C.L. Walsh, H. Watters, A.M. Zanni.
Worldwide, cities are faced with the challenge of designing and implementing the transition to a state in which their greenhouse gas emissions are drastically reduced and they are well adapted to the impacts of climate change. There is increasing understanding of the synergies and conflicts in the objectives of mitigation and adaptation. These interactions are no more vivid than in urban areas, where they play out through land use, infrastructure systems and the built environment. Urban decision makers need to understand the implications of these interactions and the potential influences of future global changes. With these decision makers in mind, the Tyndall Centre for Climate Change Research has for the last three years been developing an Urban Integrated Assessment Facility (UIAF) which seeks to simulate socio-economic change, climate impacts and greenhouse gas emissions over the course of the 21st century. The research is focussed upon London, UK, a city that has taken a lead role in the UK and globally with respect to climate protection. In this paper we describe the concept and various components within the UIAF and summarise some of the insights that have been garnered from this novel integrated analysis.
. Peter D. Bromirski, Reinhard E. Flick.
. Yang Zhang, Ping Liu, Xiao-Huan Liu, Betty Pun, Christian Seigneur, Mark Z. Jacobson, Wen-Xing Wang.
In light of non-attainment of PM2.5 in central California, the CMAQ-MADRID 1 model is applied to simulate PM2.5 mass, number, and size distributions observed during the Californi Regional PM a 10/PM2.5 Air Quality Study (CRPAQS) winter episode of 25-31 December 2000. The simulations with 12 and 24 size sections at a horizontal grid resolution of 4-km reproduce well the 24-hr average mass concentrations of PM2.5 (with normalized mean biases (NMBs) of - 6.2% to 0.5%), but with larger biases for organic matter, nitrate, and elemental carbon (with NMBs of -67% to 40.2%) and a weaker capability of replicating temporal variation of PM2.5 and its components. The coagulation process leads to a 40-91% reduction in simulated PM2.5 number concentrations. The 24-section simulation with coagulation shows the best agreement with the observed PM number and size distributions (with an NMB of -13.9%), indicating the importance of coagulation for predicting particle number and the merits of using a fine particle size resoluti n. Accurately simulating PM2.5 number and size distributions continues to be a major challenge, due to inaccuracies in model inputs (e.g., meteorological fields, precursor emissions, and the initial size distribution of PM emissions and concentrations), uncertainties in model formulations (e.g., heterogeneous chemistry, and aerosol formation, growth, and removal processes), as well as inconsistencies and uncertainties in observations obtained with different methods.
A 20th Century Acceleration in Global Sea-level Rise. Church, John A.; White, Neil J..
Geophysical Research Letters:
Multi-century sea-level records and climate models indicate an acceleration of sea-level rise, but no 20th century acceleration has previously been detected. A reconstruction of global sea level using tide-gauge data from 1950 to 2000 indicates a larger rate of rise after 1993 and other periods of rapid sea-level rise but no significant acceleration over this period. Here, we extend the reconstruction of global mean sea level back to 1870 and find a sea-level rise from January 1870 to December 2004 of 195 mm, a 20th century rate of sea-level rise of 1.7 ± 0.3 mm yr−1 and a significant acceleration of sea-level rise of 0.013 ± 0.006 mm yr−2. This acceleration is an important confirmation of climate change simulations which show an acceleration not previously observed. If this acceleration remained constant then the 1990 to 2100 rise would range from 280 to 340 mm, consistent with projections in the IPCC TAR.
A 60-year history of California soil quality using paired samples. De Clerck, F.; Singer, M. J.; Lindert, P..
How has soil quality changed in California over the past 60 years? Using the known locations of archived samples collected by the soil survey staff in the 1940s and 1950s, we resampled 125 locations in California from the Imperial Valley in the south to Tehama county in the north and analyzed samples for properties important to plant production. We collected three samples from the 0- to 25-cm depth at each location and air-dried them for analysis. For each 1945 and 2001 sample pH, electrical conductivity, total nitrogen, total carbon, plant available phosphorus, texture and color was measured. We compared the data across the entire state as well as by current land-use, and geographic region. Across the state, plant-available phosphorus, total carbon, pH, and percent clay increased significantly (95% confidence level) as did percent silt and total nitrogen (90% confidence). In contrast, electrical conductivity, and percent sand decreased significantly (95% confidence). Chroma also decreased significantly statewide (90% confidence level). The degree of change varied according to land-use and geographic region. Based on this sample, California’s soil quality has not significantly decreased over the past 60 years. These results also suggest that defining and evaluating soil quality is difficult due to conflicting trends and interpretations of soil quality indices.
Abatement costs of post-Kyoto climate regimes. Elzen, Michel Den; Lucas, Paul; Vuuren, Detlef van.
This article analyses the abatement costs of three post-Kyoto regimes for differentiating commitments compatible with stabilising atmospheric greenhouse gases concentrations at 550 ppmv CO2 equivalent in 2100. The three regimes explored are: (1) the Multi-Stage approach assumes a gradual increase in the number of Parties involved who are adopting either emission intensity or reductions targets; (2) the Brazilian Proposal approach, i.e. the allocation or reductions based on countries’ contribution to temperature increase; (3) Contraction & Convergence, with full participation in convergence of per capita emission allowances. In 2050, the global costs increase up to about 1% of the world GDP, ranging from 0.5% to 1.5%, depending on baseline scenario and marginal abatement costs. Four groups of regions can be identified on the basis of similar costs (expressed as the percentage of GDP). These are: (1) OECD regions with average costs; (2) FSU, the Middle East and Latin America with high costs; (3) South-East Asia and East Asia (incl. China) with low costs; and (4) South Asia (incl. India) and Africa with net gains from emissions trading for most regimes. The Brazilian Proposal approach gives the highest costs for groups 1 and 2. The distribution of costs for the Contraction & Convergence approach highly depends on the convergence year. The Multi-Stage approach and Contraction & Convergence (convergence year 2050) seem to result in relatively the most even distribution of costs amongst all Parties.
Abatement of ammonia and hydrogen sulfide emissions from a swine lagoon using a polymer biocover. Zahn, J A; Tung, A E; Roberts, B A; Hatfield, J L.
Journal of the Air & Waste Management Association:
The purpose of this research was to determine the efficiency of a polymer biocover for the abatement of H
Abrupt climate change. Alley, R. B.; Marotzke, J.; Nordhaus, W. D.; Overpeck, J. T.; Peteet, D. M.; Pielke, R. A.; Pierrehumbert, R. T.; Rhines, P. B.; Stocker, T. F.; Talley, L. D.; Wallace, J. M..
Large, abrupt, and widespread climate changes with major impacts have occurred repeatedly in the past, when the Earth system was forced across thresholds. Although abrupt climate changes can occur for many reasons, it is conceivable that human forcing of climate change is increasing the probability of large, abrupt events. Were such an event to recur, the economic and ecological impacts could be large and potentially serious. Unpredictability exhibited near climate thresholds in simple models shows that some uncertainty will always be associated with projections. In light of these uncertainties, policy-makers should consider expanding research into abrupt climate change, improving monitoring systems, and taking actions designed to enhance the adaptability and resilience of ecosystems and economies.
Abrupt climate change around 22 ka on the Siple Coast of Antarctica. Taylor, K C; White, J W C; Severinghaus, J. P.; Brook, E J; Mayweski, P A; Alley, R B; Steig, E J; Spencer, M K; Meyerson, E; Meese, D A; Lamorey, G W; Grachev, A; Gow, A J; Barnett, B A.
Quaternary Science Reviews:
A new ice core from Siple Dome, Antarctica suggests the surface temperature increased by B6 C in just several decades at approximately 22 ka BP. This abrupt change did not occur 500km away in the Byrd ice core, or in climate proxy records in the Siple Dome core indicative of the mid-latitude Pacific. This demonstrates there was significant spatial heterogeneity in the response of the Antarctic climate during the last deglaciation and draws attention to unexplained mechanisms of abrupt climate change in Antarctica.