Ireland's State of the Environment Report 2024

84 Chapter 4: Climate Change Projected impacts Projected climate change hazards experienced both in Ireland and further afield will result in direct, indirect, compound and transboundary risks to Ireland. There is also a risk that we will pass tipping points, which are low-probability, high-impact events that would irreversibly change our climate (Topic Box 4.3). Topic Box 4.3  Climate tipping points Climate tipping points have been identified within three types of climate sub-systems: the cryosphere (ice bodies), the circulation of the oceans and the atmosphere (circulation patterns), and the biosphere. The most recent IPCC assessment – AR6 – summarises tipping points as large-scale singular events. These encompass tipping points such as: ■ loss of the Greenland Ice Sheet, loss of major Antarctic ice sheets and associated sea level rise, carbon release from thawing permafrost (cryosphere) ■ shutdown of major ocean currents such as the Atlantic Meridional Overturning Circulation (AMOC), which includes the North Atlantic Gulf Stream (circulation patterns) ■ dieback of the Amazon rainforest, biodiversity loss and widespread geographical changes (biosphere). Climate tipping points are a source of growing scientific, policy and public concern (Lenton, 2021). Figure 4.3 depicts the most important tipping elements in the Earth system and the latest assessment of when they might be surpassed by global warming levels. Figure 4.3  The most important tipping elements in the Earth system and when they might be surpassed by global warming levels Source: Armstrong McKay et al. , 2022 The risk of reaching and exceeding climate tipping points increases as the global temperature increases. At current warming levels, the risks are already present, and new scientific understanding reflected in the IPCC’s AR6 suggests that the risks are more likely to occur at lower global warming levels than were previously envisaged.