Introduction: Understanding the global climate, how it has changed and how it will change is quite a difficult task; an extremely controversial task. Scientists have carried out numerous small-scale experiments and extrapolated the data to predict future climate and emissions trends. This article will show how extrapolating dates from small-scale experiments is not always precise and has a large margin of error. The article will discuss the different methods used by environmental scientists to attempt to extrapolate data from small-scale experiments. The emphasis being on the fact that the methods used are incapable of accounting for the many variables that should be considered in determining large-scale change. Air pollution: In a small-scale experiment conducted by Nath and Patil (2006), they used an in situ method. real-time mixing height model. Mixing height (MH) is the dispersion depth of the atmospheric boundary layer, a crucial input parameter in air pollution models (Nath et al., 2006). This model is able to obtain specific data from nearby weather stations twice a day and extrapolate the data to obtain an estimate of the MH. However, the extrapolated values ​​obtained may cause significant errors in pollution prediction due to the fact that MH is weather and site dependent. Nath and Patil claim that by using the in-situ real-time mixing height model, they could estimate the real-time values ​​on site. of MH from readily available surface measurements of temperature and wind. This data is then combined with a readily available air pollution forecast model to predict current pollution in the specified area. This model is intended for use in remote locations where development is new and there is not a single sheet of paper that can be reproduced. Otherwise, making large-scale predictions from small-scale experiments can be extremely wrong. Plant and soil, 187: 111-118, Moutinho-Pereira, JM, Bacelar, EA, Goncalves, B., Ferreira, HF, Coutinho, JF, Correia, CM (2009). Effects of open chambers on the physiological and yield characteristics of vines grown in the open field. Acta Physiol Plant, 32:395-403Nath, S., Patil, RS (2006). Prediction of air pollution concentration using a real-time in situ mixing height model. Atmospheric Environment, 40: 3816–3822Sanders, GE, Clark AG, Colls, JJ (1991) The influence of open chambers on the growth and development of fava beans. New phytol 117:439–447