Global warming is the phenomenon of the increase of the average temperature of the oceans and the Earth’s atmosphere. Measured globally over several decades it reflects an increase in the amount of heat of the Earth surface.
Global warming results in droughts, floods, diseases, migration, food shortages, possible conflicts, etc. According to the GIEC based on a huge work of reading and combining twelve thousand scientific publications, the climate change in recent decades has had impacts “on all continents and oceans”, mainly on natural systems. In many areas, the change in precipitation patterns and the melting of snow and glaciers have modified the hydraulic systems, “affecting water resources in quantity and quality”. Climate change has also impacted more “negatively” than positively on food production (wheat and corn). The range, the number of individuals or the migratory practices of many marine and terrestrial species have changed.
Deforestation and forest degradation in the world are mainly related to human activities today and are considered more profitable in the short term than the preservation or the long-term management of forests.
Deforestation corresponds to patches of forest, due to overexploitation of the forest or to free up land for other uses. It is the result of the actions of deforestation and land clearing, related to the expansion of agricultural land, exploitation of mineral resources of the subsoil, urbanization, or even excessive or uncontrolled exploitation of certain tree species. It now focuses on three major forest areas in tropical countries: the Amazon (Brazil), Indonesia and Central Africa (Republic of Congo).
Biodiversity, a contraction of “biological diversity”, is an expression denoting the variety and diversity of the living world. In its broadest sense, this word is almost synonymous with life on earth. Every region has its own species.
We often speak of climate change corresponding to an increase of the average global temperature of 0.7 °C. This increase in temperature can induce migration of species to areas where the temperature is more suited but not all species are able to migrate quickly enough. Some species could adapt but the evolution is often too slow. Finally, rising temperatures could cause species extinctions.
The phenomenal increase in human population over the centuries, from one billion people in 1800 to 6,000,000,000 in the early 21st century has multiple consequences on biodiversity. The development of agricultural land and cities transforms natural areas, we talk here about land use changes. The consequences on natural habitats are a direct destruction but also a fragmentation: they are becoming smaller and increasingly isolated from each other. In a little less than 10,000 years, it is estimated that two thirds of the globe have been changed.