Environmental concerns dominate the world scene in the XXI century. The petroleum and its derivatives are a major contributor to the non-renewable sources of energy. However, there are forecasts that in a time near the main sources of petroleum may exhaust. Thus, the search for alternative sources of energy, beside environmental necessity is essential to ensure the well being of all. The minera...

An experimental system for detecting infrared absorption using the photoacoustic (PA) effect is described. It is aimed for use at high-school level to illustrate the difference in infrared (IR) absorption among the gases contained in the atmosphere in connection with the greenhouse effect. The experimental system can be built with readily available components and is suitable for small-group exp...

Fluxes of greenhouse gases to the atmosphere are heavily influenced by microbiological activity. Microbial enzymes involved in the production and consumption of greenhouse gases often contain metal cofactors. While extensive research has examined the influence of Fe bioavailability on microbial CO(2) cycling, fewer studies have explored metal requirements for microbial production and consumptio...

The adjustment of greenhouse gas concentrations in the atmosphere to reductions in emissions depends on the chemical and physical processes that remove each gas from the atmosphere. Concentrations of some greenhouse gases decrease almost immediately in response to emission reduction, while others can actually continue to increase for centuries even with reduced emissions. The concentration of a...

The problem concerning the greenhouse effects of human activities has broadened in scope frbm the CO2-climate problem to the trace gas-climate problem. The climate ffects of non-CO 2 trace gases are strongly governed by interactions between chemistry, radiation, and dynamics. We discuss in delfiil the natuie of the trace gas radiative heating and describe the importance of radiative-chemical in...

Abstract Policies designed to control greenhouse gases imply domestic tradeoffs and international externalities, which lead both conflicts, influencing their feasibility implementations. Our paper investigates two quantitative aspects within this debate. We intend quantify the impact of: (a) internalization of externalities; (b) damage associated with a short-term view climate policies. In resp...

Background and purpose: Although greenhouse gases related with the Land Use, Land Use Changes and the Forestry (LULUCF) represent approximately 15-20% of all greenhouse gases emissions to the atmosphere, afforestation/reforestation projects of Kyoto protocol related Clean Development Mechanism (CDM) represents only 0.75% of all CDM projects. All these facts prompted re-negotiation of climate ch...

Do human activities indeed cause global warming? This paper attempts to answer this question by reexamining the time series properties of climate variables and the existence of long-run relationships between them. Double unit root testing shows that most of the radiative forcings of greenhouse gases are integrated of order two. We then apply an I(1) and I(2) cointegrating rank analysis to ident...

[1] The effect of ozone depletion on temperature trends in the tropical lower stratosphere is explored with an atmospheric general circulation model, and directly contrasted to the effect of increased greenhouse gases and warmer sea surface temperatures. Confirming and extending earlier studies we find that, over the second half of the 20th Century, the model’s lower-stratospheric cooling cause...