[en] The medium and extreme temperature time series of the stations at the airports mentioned in the Spanish abstract show increased trends in the mean temperature, especially at the airport in Medellin, which has the highest values due to the heat island effect that resulted from the airport's gradually being engulfed by the city. Likewise, it is noted that the periods from 1979 to 1982 and 1985 to 1994-95 have been relatively warm, whereas the years of 1974 to 1976 and 1984 to 1988 were relatively cool. It is also noted that the El Nino and La Nina events do influence the air temperature at those stations, which shows up as an increase or decrease of temperature, respectively

No abstract available

[en] The climatic change is one of the most sensible questions of the 21. century. Some denounce the human activities in the increasing of the temperatures, others prefer to point the uncertainties on the subject and speak of natural phenomena. This book discusses this confusion in order to present the arguments and motivations of the different points of view. It presents the climate changes and the researches on the greenhouse effect. It analyzes the causes and consequences. It presents also the alternative energies and the ways of facing the evolutions. (A.L.B.)

[en] Climate change is leading to a disproportionately large warming in the high northern latitudes, but the magnitude and sign of the future carbon balance of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for the Alaskan Arctic from four recent model intercomparison projects - NACP (North American Carbon Program) site and regional syntheses, TRENDY (Trends in net land atmosphere carbon exchanges), and WETCHIMP (Wetland and Wetland CH4 Inter-comparison of Models Project) - we provide a baseline of terrestrial carbon cycle uncertainty, defined as the multi-model standard deviation (σ) for each quantity that follows. Mean annual absolute uncertainty was largest for soil carbon (14.0±9.2 kgCm^-2), then gross primary production (GPP) (0.22±0.50 kgCm^-2yr^-1), ecosystem respiration (Re) (0.23±0.38 kgCm^-2 yr^-1), net primary production (NPP) (0.14±0.33 kgCm^-2 yr^-1), autotrophic respiration (Ra) (0.09±0.20 kgCm^-2 yr^-1), heterotrophic respiration (Rh) (0.14±0.20 kgCm^-2 yr^-1), net ecosystem exchange (NEE) (-0.01±0.19 kgCm^-2 yr^-1), and CH₄ flux (2.52±4.02 g CH₄ m^-2 yr^-1). There were no consistent spatial patterns in the larger Alaskan Arctic and boreal regional carbon stocks and fluxes, with some models showing NEE for Alaska as a strong carbon sink, others as a strong carbon source, while still others as carbon neutral. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic to evaluate the regional patterns; observed seasonal NEE was captured within multi-model uncertainty. This assessment of carbon cycle uncertainties may be used as a baseline for the improvement of experimental and modeling activities, as well as a reference for future trajectories in carbon cycling with climate change in the Alaskan Arctic and larger boreal region. (authors)

No abstract available

[en] The article discusses various climate changes and the effects they may have on the environment. The emphasis is on environmental changing mechanisms and the total end result with respect to global warming

[en] The increase in temperature due to global warming is affecting forest ecosystems worldwide. At the treeline ecotone growth is usually restricted by low temperatures. Recently, the impacts of climate change have been visible with the upward shift of the Himalaya fir (Abies spectabilis) in Nepal. Rhododendron campanulatum D. Don grows at the treeline ecotone and subalpine forest. Hardly any studies have been carried on this species in Nepal. The local people have reported that this species has been seen colonizing upper altitude in recent years, however, these needs to be verified with dendroecological studies. The study aims to assess the response of R. campanulatum to climatic variability and to evaluate the relationship of its basal diameter (Groundline) and age using dendroecological methods. Results reveal that the basal diameter was found to be significantly correlated with age (r2= 0.824, p<0.00001). Using the basal diameter age equations, attempts were made to study the age distribution along the altitudinal gradient. The species limit was observed at 4090 m asl. The age structure differed along the altitudinal gradient with multi age cohorts below the treeline and younger cohorts above the treeline. Results show that this species is migrating up at a rate of 24.7m per decade. (author)

[en] Pavements comprise an essential and vast infrastructure system supporting our transportation network, yet their impact on the environment is largely unquantified. Previous life-cycle assessments have only included a limited number of the applicable life-cycle components in their analysis. This research expands the current view to include eight different components: materials extraction and production, transportation, onsite equipment, traffic delay, carbonation, lighting, albedo, and rolling resistance. Using global warming potential as the environmental indicator, ranges of potential impact for each component are calculated and compared based on the information uncovered in the existing research. The relative impacts between components are found to be orders of magnitude different in some cases. Context-related factors, such as traffic level and location, are also important elements affecting the impacts of a given component. A strategic method for lowering the global warming potential of a pavement is developed based on the concept that environmental performance is improved most effectively by focusing on components with high impact potentials. This system takes advantage of the fact that small changes in high-impact components will have more effect than large changes in low-impact components.

[en] In today's societies, the production base made up by the industrial fabric acts as an important link between the climate and its variations and our lifestyle. However, several decades of experience have often enabled us to minimise the impact of the weather and its fluctuations on activities, making the industrial sector out to be purely artificial and protected from climate impacts. Yet climate change leads us to challenge this assumption: if the industrial base is supposed to be impervious to the current climate, is this still the case in a context of climate change? In an attempt to answer this question, the Invulnerable project was launched, led by the Institute for Sustainable Development and International Relations (IDDRI) and bringing together scientific and industrial partners (Meteo-France, IPSL, CERFACS). Observing the availability of scientific resources on climate change, partly resulting from the modeling research coordinated by the IPCC, the idea was to work with industries to identify their vulnerabilities and to use these to define indicators for climatologists. These indicators are not chosen by scientists without consulting industries, but are in fact defined by these industries to ensure they correspond to their needs as closely as possible. The challenge is therefore to bring together scientists and industries and to catalyse a mutual understanding to ensure this discussion results in one or several indicators that are relevant to the activity in question and on which climatologists can work

[en] OAK 270 - Adaptation to Climate Change ''A Research Agenda''