**2. Global climate change**

The expression of the term "climate change" according to many people means the alteration of the world's climate as a result of human activities through fossil fuel burning, clearing forests and other practices that increase the concentration of greenhouse gases (GHG) in the atmos‐ phere. This is in line with the official definition by the United Nations Framework Convention on Climate Change that states that climate change is the change that can be attributed "*directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods*" [1]. The Intergovern‐ mental Panel on Climate Change (IPCC) defines "climate change" as *"a change in the state of the climate that can be identified by changes in the mean and or the variability of its properties, and that persists for an extended period, typically decades or longer"* [2]. Climate change can be defined as a systematic change in the key dimensions of climate including average temperature and wind and rainfall patterns over a longer period of time. In recent usage, especially in the context of environmental policy, climate change usually refers to changes in modern climate. It may be qualified as anthropogenic climate change, more generally known as "global warming" or "anthropogenic global warming" (AGW).
