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.
Sea-level rise is of special importance to SIDS and coastal LDCs, as large parts of the population live near the coasts and a large share of income is generated in coastal regions. The most important processes affecting sea-level rise are increasing water temperatures throughout the oceans, which lead to thermal expansion, as well as melting of ice-sheets and glaciers. We focus on understanding how strongly sea-levels will rise at different levels of warming and the plausibility and likelihood of changes in the individual components leading to total sea-level rise.
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.
A reminder for the 'Blue COP' - limiting warming to 1.5°C crucial for protecting oceans and ocean servicesBriefing papers
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.
The multicentennial sea-level rise commitment of pledged near-term emission reduction efforts under the Paris Agreement has not been quantified yet. This report estimates this sea-level rise commitment and find that pledged emissions until 2030 lock in 1m of sea-level rise in the year 2300.
Committed sea-level rise under the Paris Agreement and the legacy of delayed mitigation actionPeer reviewed
Sea-level rise is a major consequence of climate change that will continue long after emissions of greenhouse gases have stopped. The 2015 Paris Agreement aims at reducing climate-related risks by reducing greenhouse gas emissions to net zero and limiting global-mean temperature increase. This study quantifies the effect of these constraints on global sea-level rise until 2300, including Antarctic ice-sheet instabilities.
Linking sea level rise and socioeconomic indicators under the Shared Socioeconomic PathwaysPeer reviewed
This paper incorporates latest findings on Antarctic ice sheet dynamics into new sea level rise modelling, and pairs it with the new generation of scenarios – Shared Socioeconomic Pathways (SSPs) and compares them with outcomes for the previous generation of scenarios - Representative Concentration Pathways (RCPs), used in the last IPCC Assessment (AR5). It finds that without any mitigation, sea levels could rise by an average of 132 cm in 2100 relative to the 1986-2005 mean.
Differential climate impacts for policy-relevant limits to global warming: the case of 1.5 °C and 2 °CPeer reviewed
This article is a first comprehensive assessment of key climate impacts for the policy relevant warming levels of 1.5 °C and 2 °C above pre-industrial levels. It finds substantial impact differences in intensity and frequency of extreme weather events, regional water availability and agricultural yields, sea-level rise and risk of coral reef loss. The increase in climate impacts is particularly pronounced in tropical and sub-tropical regions.
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.