The human activities change the environment and influence climate. In some cases the chain of causality is direct and unambiguous (e.g., by the effects of irrigation on temperature and humidity), while in others it is less clear. Various hypotheses for human-induced climate change have been debated for many years, though it is important to note that the scientific debate has moved on from scepticism, as there is scientific consensus on climate change that human activity is beyond reasonable doubt as the main explanation for the current rapid changes in the world's climate. Consequently in politics, the debate has largely shifted onto ways to reduce human impact and adapt to change that is already 'in the system.'

The biggest factor of present concern is the increase in CO2 levels due to emissions from fossil fuel combustion, followed by aerosols (particulate matter in the atmosphere), which exert a cooling effect, and cement manufacture. Other factors, including land use, ozone depletion, animal agriculture and deforestation, also affect climate. (Wikipedia)

Film made by Dan Alexoae