Abstract
An outline is given of the global warming process due to increase of the greenhouse gases in the atmosphere. The recent long-term trend of the observed air temperature averaged over the global oceans shows a warming of about 0.3℃/90 years. The numerical experiment results of climate change due to increasing CO_2 is compared with the observed recent warming, and some problems to be solved are indicated. Important roles of the aerosols and oceanic thermohaline circulation are suggested.
