Greenhouse gases have influenced in enormous ways to global warming and climate change. The alarming rise of the toxic gases poses a serious threat to the future of mankind. Traditionally wireless sensor based monitoring systems have been used to monitor the concentration of greenhouse gases in the environment. It is not always possible to access the area of interest to deploy the sensor node or even do maintenance in case of failure. Therefore in this paper we proposed and implemented unmanned aerial vehicle (UAV) based greenhouse gases monitoring system which assembles humidity sensor, gas sensors and temperature sensors. The proposed UAV system equipped with sensors collect data from the atmosphere and predicting future humidity, temperature and gasses. In this paper, we collect these data from three different areas Uttara, Aftabnagar and Mirpur in Bangladesh. Our analysis shows that air quality is better in Aftabnagar, though it is variable depending on the different time of the day. For automatic collection of environmental sample, our proposed system mainly features high precision of aerial platform.