Assista o primeiro video do projeto Trike Eletrico:https://www.youtube.com/watch?v=LSaSypU5bbI For the last fortyyears, the world has been aware about a possible planetary climate changeinduced by Carbon Dioxide emissions from fuel fossil burning. In fact, theIPCC, a United Nations organization, states that they are 99% sure that thehuman being is the major responsible for the rising global temperatures sincethe beginning of the Industrial Revolution (Stocker et all, 2013, p 5-7). However, many peoplehave a different opinion about this issue. This group, that includes peoplefrom different occupations like climatologists, physicians, and geographers,are known as skeptics, since they partially or totally disagree with thistheory. Many of them states that there is no conclusive evidence about theclimate change, while others dont agree that the rising CO2 concentration iscapable to alter the world climate. The purpose of this paper is to analyze theskeptics claims about climate change in order to understand why they are so skepticalabout a well-documented and peer-revised topic like climate change. Some issuespointed by the skeptics are improper methodology, excessive reliance oncomputer models, misinterpretation of historic climatic register, and biasedscience.Is Global temperatures really rising? The first question that comes inmind is: what the term average global temperaturemeans? It is possible to have a single representative temperature for theentire planet? That is the first point cast in doubt for many skeptics, sincethis number can vary according to the adopted methodology. To obtain thisnumber, meteorologists and climatologists rely on temperature informationprovided by hundreds of meteorological stations spread around the world. Thosestations are where the problem begins. Some critics argue that temperaturesnear cities are higher than that measured in the country or in the forests.This difference is attributed to the urbanheat island effect, a warming effect caused by buildings, cars, industry,asphalt, reduced vegetation areas, etc., that changes the air circulationpatterns, albedo, air humidity, and several other factors, causing a differenceof temperature between city and the country that can reach 12oC (Akasofu, 2010).Therefore, if a meteorological station is located in an urban area, its temperaturemeasures are subject to the same trend. Anotherpoint that concerns the Skeptics is that several rural meteorological stationshave been closed in the last years. They also claim the existence of a strongcorrelation between rising temperatures and the reduction of those ruralstations (DAleo, 2002). Therefore, the current rising temperatures would bejust a consequence of the way data is collected. Skeptics have been complainingthat temperature data in the United States is not completely available for pairreviewing, making more difficult to verify the quality of the data involved inclimatic modeling (Global Climate Change Facts, n.d.).Figure 1. Thisgraphic shows the correlation between the number of meteorological stations (bluedots) and the average temperature (purple bars). The rising temperatures in1990 coincide with the closing of several stations most of them in ruralareas - around the world (Global climate change facts, nd).Why different modelsshow different results? Themain tool used by climatologists to predict climate tendencies is computermodeling. Those models are very useful for weather forecasts, providingreliable three to four days prognostics. Nevertheless, when the same modelsare used to climatic forecasts, which involves larger periods, the results divergeamong them. The model forecasts also