The Earth system, encompassing the atmosphere, hydrosphere, geosphere, cryosphere, and biosphere, is very complex with each component affecting and being affected by every other component on a wide range of time and space scales ranging from seconds to the age of the Earth and from microscopic to thousands of kilometers. As a result of this complexity the implications of particular climate changes for each of the components of the Earth system, the predication of future climate change, and the identification of causes of climate change are very difficult to determine.
Worldwide temperature measurements indicate that there has been a warming of the global annual mean surface temperature of between 0.3oC and 0.6oC over the last 150 years. However, this warming has not been steady, with fluctuations amounting to a significant fraction of the overall warming. Such changes in the surface temperature have implications for other parts of the climate system including precipitation, evaporation, sea level, and the biosphere. In this talk the kinds of changes that have been observed over the last 150 years and predictions of changes for the next 100 years will be discussed. We will explore the impacts and potential impacts of these changes on the different components of the Earth system. Finally, the possible causes of the observed and predicted climate changes and the difficulty of identifying the causes with respect to natural variability and anthropogenic influences will be discussed.

Key words: climate change, Earth system science