Human-induced climate change is causing a dangerous and generalized perturbation in nature and it is affecting the life of billions of people worldwide. The people and ecosystems with a lower capacity to deal with this situation are the most affected ones, according to the Intergovernmental Panel on Climate Change (IPCC). The world is facing several climate risks that we will experience over the next two decades, and which have caused, in the Mediterranean, a warming of 1.5ºC.
If the emissions are not reduced over the next decades and the warming level set in the Paris Agreement (1.5º) is exceeded, there will be serious impacts, and some of them will be irreversible.
According to the scientific community, between 3.3 and 3.6 billion people live in a context which is highly vulnerable to climate change, almost half of humanity. Globally, the most vulnerable areas are Central Africa, Southeast Asia, and Central America, while, in the European continent, the most threatened region is the Mediterranean area. The study highlights that the current economic development is unsustainable, and it is essential to consider the inclusive participation of all social actors, as well as equity and climate justice, to develop mitigation and adaption actions towards a sustainable and climate-resilient model.
The summary of the IPCC report considers the vulnerability of humans and that of the ecosystems to be interdependent. Therefore, it puts emphasis on the current and future effects of climate change in biodiversity. More than 40,000 studies covering marine and terrestrial systems. Science says that increased heatwaves, droughts and floods are already exceeding the tolerance threshold of many plants and animals, which has caused, on the one hand, local extinctions of populations of some temperature-sensitive or low-mobility species, such as endemic and more specialist species; and on the other, mass mortality of species in habitats that are more vulnerable to heat stress, such as seagrass meadows and coral reefs. The report is supported by scientific studies that warn that more than 50% of the planet species have moved over the last years, either to northern latitudes or to higher altitude areas, to escape the rising temperatures.
Moreover, the document analyses the risk of extinction of more than 100,000 species for which we have scientific documentation. The report does not include results or information of species at a local level because each species has a unique ecology and each pattern is extremely complex, but it does highlight the first extinction documented of a mammal species: the mosaic-tailed mouse (Melomys rubicola), native to a low-altitude tropical island (Bramble Cay) near Papua New Guinea, which disappeared after its habitat was drastically reduced due to extreme climate impacts and the rising sea levels.
Adaptation measures to maintain biodiversity, whose services we absolutely depend on as a society, include the restoration of ecosystems, application of nature-based solutions and the increase of protected land. The report suggests moving from 16% of world protected areas —a figure agreed on in the world agreements on biodiversity— to the 30% or 50% by 2030.