The observed increase has varied geographically, with the largest increase occurring in the winter and spring in the mid-latitude continents. The seasonal and inter-annual variability has increased in some regions and decreased in others. Global sea-level has risen by 10 to 25 cm over this period. Potential Future Climate Changes and Impacts Numerical climate models were used by the IPCC to provide a range of estimates of the future global warming that may occur due to the increase in greenhouse gases. The projected average rate of warming could be greater than what has occurred during the last 10,000 years.
Sea level is projected to rise due the thermal expansion of the oceans and the melting of glaciers.
The 1995 IPCC report provided assessments of the potential impacts of climate change on natural ecological systems, socio-economic systems, and human health. It also assessed the possible effects of various mitigation strategies on different regions around the world.