The United Nations Group of Experts on Climate Change (GIEC) released a new report on Monday stating that climate change is already underway and that drastic, large-scale action is needed at a time when about half the world's population is already vulnerable to global warming.

Droughts, floods, heat waves, fires, food insecurity, water shortages, diseases, rising water levels, these are some of the phenomena evoked not in the future, but already in the present by UN experts who, in their latest report published this Monday, state that 3.3 to 3.6 billion people are already "very vulnerable.

In this 3,675-page document, scientists find that the planet's temperature, which has already increased by 1.1°C since the pre-industrial era, could increase by 1.5°C by 2030, or 10 years earlier than predicted as recently as 2015, making it difficult to maintain the goal of a maximum 1.5°C increase by the end of the century without drastic, widespread, and immediate action, as recommended in this new report.

The GIEC experts also point out that if this limit is exceeded - even temporarily - this could cause further "irreversible" damage to fragile ecosystems such as poles, mountains, and coastal areas, and could also cause the disappearance of 3 to 14% of terrestrial species.