Online search systems of four major newspapers in Japan were used to find long-term changes in the coverage of key words related to climate change and summer heat for the period 1990 to 2019. It is shown that the coverage of "global warming" has an interannual variation with maxima corresponding to the publication of IPCC reports, with a distinct surge from 2007 to 2010. On the other hand, the coverage of "heat island" decreased markedly and that of "heat stroke" increased rapidly in the 2010s.

Green spaces are considered to be an effective way of mitigating the urban heat island effect. The reduction in wind speed behind trees and buildings modifies the environmental conditions or microclimate. This phenomenon is known as the Hidamari effect. In this study, we developed the practical measurement method, and we applied it for understanding the effect of wind speed reduction by trees in green space on the temperature field.