This is part of a series on the effects of climate change.
How is climate change driving biodiversity loss?
On land, warmer temperatures force certain species to move to higher latitudes, while extreme weather events (such as floods, storms, hurricanes, and wildfires), and sea level rise invade the habitats of others. Species that cannot relocate or adapt to the new conditions face extinction. For example, it is estimated that four percent of terrestrial and 13 percent of marine species would be at high risk of extinction in biodiversity hotspots for a warming scenario between 1.5 and two degrees Celsius. For warming above three degrees Celsius, these shares would rise to 20 and 32 percent, respectively.In marine ecosystems, climate change has driven an increase in the average ocean surface temperature. In addition, the absorption of carbon dioxide from the atmosphere increases the water’s acidity. Marine ecosystems are extremely sensitive to even seemingly small variations in water conditions, with drastic outcomes expected. It is forecast that in a warming scenario of two degrees Celsius above pre-industrial levels, 99 percent of coral reefs worldwide will vanish. As of 2023, the global temperature had increased by 1.3 degrees Celsius above the pre-industrial average.
The effects of biodiversity loss
The climate and the biodiversity crises are tightly connected. While climate change is driving up the rate of biodiversity loss through rising temperatures and extreme weather events, the loss of biodiversity can also aggravate climate change. With the loss of species, the Earth is reaching certain tipping points, turning forest areas from natural carbon sinks to carbon sources. Similarly, coastal ecosystems such as sea grass, mangroves, and salt marshes, can sequester carbon. When destroyed or degraded, they release carbon back into the atmosphere. Even before reaching this tipping point, their carbon storage capacity is highly reduced by habitat degradation. The area of coastal mangroves worldwide has declined by more than three percent in just over two decades.Aiming to halt and revert global biodiversity loss, the first Global Biodiversity Framework was passed during the 15th Conference of parties to the Convention on Biological Diversity (COP15) in December 2022. This landmark agreement lists 23 targets focused on reducing threats to biodiversity, meeting the needs of the population through sustainable use and benefit-sharing, and implementing tools and solutions for prior goals, such as designating 30 percent of Earth’s land and oceans as protected areas by 2030. The progress on targets is scheduled to be discussed in October 2024, at COP16 in Colombia.