This briefings summarise the impacts of global warming at and above 1.5°C relative to pre-industrial levels. Key information is extracted from the Special Reports of the Intergovernmental Panel on Climate Change (IPCC) of its sixth assessment report cycle (AR6). These Special Reports represent an invaluable resource to understand the impacts of exceeding 1.5°C and new science published after their compilation has only contributed to an ever clearer picture of the grave consequences of exceeding that limit. In addition to the overview on climate impacts based on the Special Reports, latest information on global mitigation efforts and requirements to meet the 1.5°C limit are also included.
Ocean acidification
Besides increases in temperatures, the world’s oceans also take up CO2, leading to a lowering of pH-levels in the water. This process is especially relevant to marine ecosystems and coral reefs, which are very sensitive to changes in ocean chemistry. Strong ocean acidification depresses metabolic rates in some organisms and reduces the ability of species to sequester calcium required for building shells and skeletons, or even leads to dissolving existing coral reef structures. We assess greenhouse-gas emission scenarios regarding the possibility to prevent the worst of the projected effects of ocean acidification.
Publications
The IPCC Special Report on Global Warming of 1.5°C sent a message of urgency. The IPCC Special Report on the Ocean and Cryosphere in a Changing Climate re-emphasises it and adds the dimensions of legacy of our actions. It shows how changes in ocean and cryosphere will continue for centuries and millennia even after emissions have seized.
Ocean systems are particularly vulnerable to climate change and are already heavily impacted today. This briefing provides an overview of the latest science including from the latest IPCC special reports on key risks for ocean systems including from sea-level rise, ocean acidification and impacts on marine and coastal ecosystems. The analysis underscores the need to limit warming below 1.5°C to limit impacts on ocean systems. It is clearer than ever that exceeding that warming level will fundamentally affect ocean systems and undermine any other attempts to protect them. Limiting warming to 1.5°C remains of paramount importance to safeguard the oceans.
Ocean systems are particularly vulnerable to climate change, and there is already clear evidence for loss and damage inflicted by climate change on ocean systems. This briefing provides an overview of the latest science on key risks for ocean systems including from sea-level rise, ocean acidification and impacts on coral reefs and other marine and coastal ecosystems.
Third report in the Turn Down the Heat series assesses climate risks in Latin American and the Caribbean, Middle East and North Africa and Europe and Central Asia.
This report focuses on the risks of climate change to development in Sub-Saharan Africa, South East Asia and South Asia.
This report provides a snapshot of recent scientific literature and new analyses of likely impacts and risks that would be associated with a 4° Celsius warming within this century.
Projects
Science and policy to assist and support SIDSs and LDCs to negotiate a strong international climate regime, enabling low carbon development and supporting adaptation needs.