The impacts of a plume-rise scheme on earth system modeling: climatological effects of biomass aerosols on the surface temperature and energy budget of South America

Theoretical and Applied Climatology - Seasonal forest fires in the Amazon are the largest source of pollutants in South America. The impacts of aerosols due to biomass burning on the temperature...     

The economics of boldness: equity,action, and hope

Equity is usually interpreted in terms of the concept of justice, such that an equitable share of the atmospheric space is understood in terms of past emissions. This emphasizes the collective nature of sharing the burden of mitigation and the duty to act for those who have emitted the most. An alternative is considered: the aggregate costs and benefits to all Parties that could result from both increasing the level of collective ambition and implementing a climate regime that supports bold actions across all Parties. The regional impacts and carbon flow costs across differentiated scenarios are assessed and it is argued that the majority of developing-country Parties would be better off if a high ambition outcome to which all contributed, but some more than others. Moreover, those with middle or low emissions would have proportionally more to gain (or lose) relative to the level of ambition compared to those that have had higher emissions. The climate regime should be built on the principle of common but differentiated responsibility and respective capabilities (CBDR&RC), in which all act early even if some do much more; one that accounts for justice but does not forget hope.

Policy relevance

Differing interpretations of equity and the principles of the United Nations Framework Convention on Climate Change (UNFCCC) are discussed, with a focus on how these can enhance or hinder collective action. Whilst the climate change negotiations are usually taken as games in which one party gains and another loses, and interactions are dogged by continuous conflict, it is explored instead how negotiation responses can be framed in terms of cooperation. This would emphasize the gains that could be achieved by common but differentiated collective action, which could result in a collective avoidance of impacts. The possibilities that this shift of perspective could bring are explored by comparing costs under global cooperation (or lack of it). It is found that cooperation reduces the total costs for these regions. Thus, thinking in terms of cooperation focuses the options for negotiation on the means and interpretations of the UNFCCC principles that spur action and avoid climate impacts through collective action.     

Climate change and the incidence of a forest pest in Mediterranean ecosystems: can the North Atlantic Oscillation be used as a predictor?

Many forest pest species strongly depend on temperature in their population dynamics, so that rising temperatures worldwide as a consequence of climatic change are leading to increased frequencies and intensities of insect-pest outbreaks. In the Mediterranean area, the climatic conditions are strongly linked to the effects of the North Atlantic Oscillation (NAO). The aim of this work is to analyze the dynamics of the pine processionary moth (Thaumetopoea pityocampa), a severe pest of Pinus species in the Circunmediterranean, throughout a region of southern Spain, in relation to NAO indices. We related the percentage of forest plots with high defoliation by pine processionary moth each year with NAO values for the present and the three previous winters, using generalized linear models with a binomial error distribution. The time series is 16-year long, and we performed analyses for the whole database and for the five main pine species separately. We found a consistent relationship between the response variable and the NAO index. The relationship is stronger with pine species living at medium-high altitudes, such as Aleppo (P. halepensis), black (P. nigra), and Scots (Pinus sylvestris) pine, which show the higher defoliation intensities up to 3?years after a negative NAO phase. The results highlight, for the first time, the usefulness of using global drivers in order to understand the dynamics of pest outbreaks at a regional scale, and they open the window to the development of NAO-based predictive models as an early-warning signal of severe pest outbreaks.     

Costing the impact of climate change on tourism in Europe: results of the PESETA project

Climate change might lead to large shifts in tourist flows, with large economic implications. This article simulates the effect of future climate change by the 2080s on outdoor international tourism expenditure within Europe. The assessment is based on the statistical relationship between bed nights and a climate-related index of human comfort, after accounting for other determinants of bed nights such as income and prices. It is concluded that climate change could have significant impacts on the regional distribution of the physical resources supporting tourism in Europe. For example, in summer, Southern Europe could experience climate conditions that are less favourable to tourism than the current climate, while countries in the North could enjoy better conditions. The economic effects of these changes are likely to be sizeable, albeit difficult to assess. Crucially, they are shown to depend on tourists’ temporal flexibility with respect to holiday planning. The greater the prominence of institutional rigidities such as school holidays, the larger the differences between winning and losing regions in terms of economic impact.     

Downscaling of South America present climate driven by 4-member HadCM3 runs

The objective of this work is to evaluate climate simulations over South America using the regional Eta Model driven by four members of an ensemble of the UK Met Office Hadley Centre HadCM3 global model. The Eta Model has been modified with the purpose of performing long-term decadal integrations and has shown to reproduce “present climate”—the period 1961–1990—reasonably well when forced by HadCM3. The global model lateral conditions with a resolution of 2.5° latitude?×?3.75° longitude were provided at a frequency of 6?h. Each member of the global model ensemble has a different climate sensitivity, and the four members were selected to span the range of uncertainty encompassed by the ensemble. The Eta Model nested in the HadCM3 global model was configured with 40-km horizontal resolution and 38 layers in the vertical. No large-scale internal nudging was applied. Results are shown for austral summer and winter at present climate defined as 1961–90. The upper and low-level circulation patterns produced by the Eta-CPTEC/HadCM3 experiment set-up show good agreement with reanalysis data and the mean precipitation and temperature with CRU observation data. The spread in the downscaled mean precipitation and temperature is small when compared against model errors. On the other hand, the benefits in using an ensemble is clear in the improved representation of the seasonal cycle by the ensemble mean over any one realization. El Ni?o and La Ni?a years were identified in the HadCM3 member runs based on the NOAA Climate Prediction Center criterion of sea surface temperature anomalies in the Ni?o 3.4 area. The frequency of the El Ni?o and La Ni?a events in the studied period is underestimated by HadCM3. The precipitation and temperature anomalies typical of these events are reproduced by most of the Eta-CPTEC/HadCM3 ensemble, although small displacements of the positions of the anomalies occur. This experiment configuration is the first step on the implementation of Eta-CPTEC/HadCM3 upcoming experiments on climate change studies that are discussed in a companion paper.     

High-temperature emplacement of the Cerro Galán and Toconquis Group ignimbrites (Puna plateau,NW Argentina) determined by TRM analyses

Estimates of pyroclastic flow emplacement temperatures in the Cerro Galán ignimbrite and Toconquis Group ignimbrites were determined using thermal remanent magnetization of lithic clasts embedded within the deposits. These ignimbrites belong to the Cerro Galán volcanic system, one of the largest calderas in the world, in the Puna plateau, NW Argentina. Temperature estimates for the 2.08-Ma Cerro Galán ignimbrite are retrieved from 40 sites in 14 localities (176 measured clasts), distributed at different distances from the caldera and different stratigraphic heights. Additionally, temperature estimates were obtained from 27 sample sites (125 measured clasts) from seven ignimbrite units forming the older Toconquis Group (5.60–4.51 Ma), mainly outcropping along a type section at Rio Las Pitas, Vega Real Grande. The paleomagnetic data obtained by progressive thermal demagnetization show that the clasts of the Cerro Galán ignimbrite have one single magnetic component, oriented close to the expected geomagnetic field at the time of emplacement. Results show therefore that most of the clasts acquired a new magnetization oriented parallel to the magnetic field at the moment of the ignimbrite deposition, suggesting that the clasts were heated up to or above the highest blocking temperature (T _b) of the magnetic minerals (T _b = 580°C for magnetite; T _b = 600–630°C for hematite). We obtained similar emplacement temperature estimations for six out of the seven volcanic units belonging to the Toconquis Group, with the exception of one unit (Lower Merihuaca), where we found two distinct magnetic components. The estimation of emplacement temperatures in this latter case is constrained at 580–610°C, which are lower than the other ignimbrites. These estimations are also in agreement with the lowest pre-eruptive magma temperatures calculated for the same unit (i.e., 790°C; hornblende–plagioclase thermometer; Folkes et al. 2011b). We conclude that the Cerro Galán ignimbrite and Toconquis Group ignimbrites were emplaced at temperatures equal to or higher than 620°C, except for Lower Merihuaca unit emplaced at lower temperatures. The homogeneity of high temperatures from proximal to distal facies in the Cerro Galán ignimbrite provides constraints for the emplacement model, marked by a relatively low eruption column, low levels of turbulence, air entrainment, surface–water interaction, and a high level of topographic confinement, all ensuring minimal heat loss.     

Midnight reversal of ionospheric plasma bubble eastward velocity to westward velocity during geomagnetically quiettime: Climatology and its model validation

In an effort to better understand the dynamics of westward velocities of the nocturnal F-region plasma, the climatology of the westward traveling plasma bubbles – WTB – occurring during quiettime is studied here. The climatology of the WTB is analyzed here based on airglow images obtained during 14 quiet days between 2001 and 2006 at the Brazilian station São João do Cariri (Geographic 7.45°S, 36.5°W, dip ～20°S). The frequency of occurrence of the WTB maximizes in the descending phase of the solar cycle. The WTB velocities ranged between ～20 and 40 ms^?1. The frequency of occurrence had a peak value of only 3.65% at 2345 LT. The maximum occurrence of the WTB was in July–September. No WTB have been observed from November until April in all years 2001–2006. We show for the first time theoretically that the WTB dominant forcing mechanisms during geomagnetically quiet days are westward thermospheric winds.     

Investment risk and return under renewable decarbonization of a power market

How does financial performance risk affect investments in low-carbon electricity-generating technologies to achieve climate policy targets? A detailed risk simulation of price formation in the Great Britain wholesale power market is used to show that the increasing replacement of fossil facilities with wind, ceteris paribus, may cause a deterioration of the financial risk–return performance metrics for incremental investments. Low-carbon investments appear to be high risk, low return, and as such may require a progressively higher level of support over time than envisaged by the conventional degression trajectories. The increasing riskiness of the wholesale market will to some extent offset the benefits of lower capital costs and operational efficiencies if investors need to satisfy cautious debt coverage ratios alongside positive expected returns. This increased risk is additional to the well-known ‘merit order effect’ of low-carbon investments progressively depressing wholesale prices and hence their expected investment returns.

Policy relevance

Policy support for renewable technologies such as wind is usually based upon levelized costs and is expected to reduce over time as capital costs and operational efficiencies improve. However, levelized costs do not take full account of the risk aversion that investors may have in practice. Expected policy support reductions may be moderated to some extent by the increased financial performance risk that intermittent technologies bring to the power market. The annual risk-return profiles for incremental investments deteriorate for all technologies as wind replaces fossil fuels. This extra risk premium will need to be incorporated into evaluating policy incentives for new investments in a decarbonizing power market.     

The droughts of 1997 and 2005 in Amazonia: floodplain hydrology and its potential ecological and human impacts

It is well known that most of the severe droughts in Amazonia, such as that of 1997, are El Niño-related. However, in 2005, the Amazon was affected by a severe drought that was not El Niño-related, as most of the rainfall anomalies that have happened in southwestern Amazonia are driven by sea surface temperature anomalies in the tropical North Atlantic. Earlier studies have analyzed both droughts in terms of their meteorological causes and impacts in terra firme (non-flooded) forests. This study compares the hydrological effects of both droughts on the Amazonian floodplain and discusses their potential ecological and human impacts based on an extensive literature review. The results revealed that the effects of the 2005 drought were exacerbated because rainfall was lower and evaporation rates were higher at the peak of the dry season compared to the 1997 drought. This induced a more acute depletion of water levels in floodplain lakes and was most likely associated with higher fish mortality rates. Based on the fact that the stem growth of many floodplain species is related to the length of the non-flooded period, it is hypothesized that the 1997 drought had more positive effects on floodplain forest growth than the 2005 drought. The fishing community of Silves in central Amazonia considered both droughts to have been equally severe. However, the 2005 drought was widely broadcasted by the press; therefore, the governmental mitigation efforts were more comprehensive. It is suggested that the availability of new communication technology and greater public awareness regarding environmental issues, combined with the new legal framework for assessing the severity of calamities in Brazil, are among the primary factors that explain the difference in societal response between the two droughts.     

Modeling monthly mean air temperature for Brazil

Air temperature is one of the main weather variables influencing agriculture around the world. Its availability, however, is a concern, mainly in Brazil where the weather stations are more concentrated on the coastal regions of the country. Therefore, the present study had as an objective to develop models for estimating monthly and annual mean air temperature for the Brazilian territory using multiple regression and geographic information system techniques. Temperature data from 2,400 stations distributed across the Brazilian territory were used, 1,800 to develop the equations and 600 for validating them, as well as their geographical coordinates and altitude as independent variables for the models. A total of 39 models were developed, relating the dependent variables maximum, mean, and minimum air temperatures (monthly and annual) to the independent variables latitude, longitude, altitude, and their combinations. All regression models were statistically significant (α?≤?0.01). The monthly and annual temperature models presented determination coefficients between 0.54 and 0.96. We obtained an overall spatial correlation higher than 0.9 between the models proposed and the 16 major models already published for some Brazilian regions, considering a total of 3.67?×?10⁸?pixels evaluated. Our national temperature models are recommended to predict air temperature in all Brazilian territories.