It is generally accepted that a human emissions of greenhouse gases upset the thermal balance of the earth-atmosphere system and ultimately lead to global climate changes. The extent of the changes will depend on future emissions of greenhouse gases and will vary between the Earth's different regions. But a central estimate for the Nordic Region is that, by 2100, the temperature will have increased by about 3ºC, average rainfall will be 10% higher and the sea level may have raised 40 cm. The content of the book : the problem, Nordic engergy situation, climate scenarios, statistical analysis, hydropower, wind power, solar energy, biofuels, energy system analysis and conslusions.