Nobel Laureate Mario Molina will be presenting "Science and Policy of Climate Change" on October 28, 2015. Abstract: Climate change is the most serious environmental challenge facing society in the 21st century. The average temperature of the Earth?s surface is increasing, and the frequency of extreme weather events such as droughts and floods is also increasing, most likely as a consequence of human activities such as burning fossil fuels and deforestation. The basic science of climate change is well established; however, the Earth?s climate is a complex system, and consequently there are uncertainties in the projections of future climate impacts. However, the consensus among experts is that for a business as usual emissions scenario the risk of having potentially devastating impacts later in the Century is substantial. Such a risk is certainly not acceptable, particularly considering that various economic analysis indicate that the cost of taking the necessary measures to minimize the risk is relatively modest. Unfortunately climate change policy has become politically contentious in good measure as a consequence of efforts to undermine public confidence in its scientific foundations. Thus, the scientific community needs to significantly improve the way climate change science is communicated to the public.