Global warming is the long term heating of Earth’s surface caused as a result of natural or human activities primarily burning of fossil fuel, bush burning, logging, and other anthropogenic processes as a result of population increase, which result in increased emission of greenhouse gases such as, Carbon (iv) Oxide, Nitrous oxide, Chlorofluorocarbons, Ozone, Methane, Sulphur oxide and so on. Teaching and learning of global warming in secondary school is still very unpopular. This study adopted a quasi-experimental design. This study explore field trip and inquiry methods to teach global warming to 300 Chemistry students drawn from 10 schools in Boki and Etung Local Government Areas in Central Educational zone of Cross River State (150 students from each area of study) by criterion reference sampling technique. The choice of these Local Government Areas is based on the fact that activities that can result in global warming are high in these areas. The students were selected by simple balloting with replacement from a population of 3000 senior secondary (SSII) Chemistry students in the area of study. The instrument used was a 20 item achievement test tagged Global Warming Achievement Test (GWAT).The reliability of the instrument which was tested with Cronbach Alpha gave a reliability of 0.68 which indicates that the test was reliable. Students from Boki L.G.A were taught using the field trip method, while those from Etung L.G.A were tutored using Inquiry method. The methods of instruction were carried mainly in the forest where activities of logging were prevalent for two weeks for each group simultaneously with the help of Research Assistants. At the end of the teaching session, a twenty (20) item achievement test, Global Warming Achievement Test (GWAT) was given as post-test for one hour. The scripts were collected and marked over 100%.  The results were analysed using Analysis of covariance (ANCOVA). The findings indicated no significant relationship between the achievement scores of students taught with field trip and those taught without field trip. The findings also showed no significant relationship between achievement scores of students taught with inquiry method and those taught without inquiry method. The findings however indicated no significant interaction effects between male and female students when taught using the teaching approaches. The study recommended among others, that hands-on and practical teaching strategies to be introduced in the curriculum for effective teaching and learning of global warming.