As the making of political consensus on global climate change policies has not been advanced, engineering solutions of climate change attract increased attention among scientists. That means that climate change by greenhouse gases could be controlled by using geoengineering technologies. The scientists who promote geoengineering solutions point out the failure of policies to reduce greenhouse gases actually. They insist that geoengineering could provide us with more economic and efficient solutions than mitigation policies. However, geoengineering technologies confront criticism with regards to ethics of responsibility, because ecological impacts of those technologies are too huge to predict and be controlled. With the uncertainty of prediction, geoengineering solutions can not confirm economic effects. On the contrary, the gap between return and risk will deepen by applying geoengineering technologies. It is suggested that social, political solutions based on easily reversible human actions could help to manage climate change risk more fundamentally than geoengineering technologies. In order to applying geoengineering inevitably, we should revise present ethical guidelines of science and technology.