There is scientific agreement that emissions from human activities are increasing the concentrations of certain gases in the Earth's atmosphere. The burning of fossil fuels for heat and energy is the main source of emissions. These additional greenhouse gases enhance the Earth's natural greenhouse effect, causing the Earth to warm. To further complicate this situation, the warming caused by human emissions increases evaporation rates. This results in more water vapour being stored in the atmosphere.
Water vapour is the main greenhouse gas, so the warming trend is compounded.
The scientists also agree that the Earth's average temperature has increased by 0.3 to 0.6 C over the past 100 years. If nothing is done to reduce human emissions of greenhouse gases, the best estimates indicate that we can expect a further increase of 1 C by 2050 and 2 C or more by the end of the 21st century. The basic science of climate change is not at issue. The role of greenhouse gases in regulating climate is well known, and their build-up in the atmosphere has been well documented. It is getting warmer down here.