The production of energy from fossil fuels is causing a climate change with its unpredictable consequences for mankind and biodiversity. Burning fossil fuels and biomass produces fine-particle emissions in the atmosphere. These particles are dangerous for health, causing the death of more than one hundred thousand European citizens annually. According to the climate specialists, bringing the climate change to an acceptable level demands a reduction of greenhouse gases (GHGs) by 60% to 80 % within a couple of decades. The Kyoto Protocol is one of the first steps aiming at slowing down the climate change. 55 countries have agreed to reduce emissions by the year 2010 by an average of 5 % as compared with the emission level in the year 1990. The main factors causing climate change are the carbon dioxide emissions from energy production. In almost all Kyoto Protocol countries except for the transition countries of central and eastern Europe emissions have grown since 1990 and are predicted to do so till the year 2010. Thus, realisation of the Protocol is very difficult. The technical solutions are to save energy, improve energy efficiency and reduce carbon dioxide emissions in energy production and use. In the future it might also be possible to apply carbon dioxide sequestration. An improvement in energy efficiency due to developments in technology has already been taken into account in the energy scenarios. There are large saving potentials in the heating and cooling of buildings for example.