To study the feasibility of a carbon-tax implementation, the results of observations of global changes which occurred during the last quarter of a century are analysed and compared with various forecasts. It is shown that carbon-tax implementation, without massive forest protection measures, will merely lead to a short-term and insignificant temperature effect. Therefore, the results of this study demonstrate that for climate protection the implementation of global carbon tax seems unnecessary. It is argued that adequate measures for forest preservation and restoration will be more effective and universal.