<p>The risk of triggering multiple climate tipping points if global warming levels were to exceed 1.5°C has been heavily discussed in recent literature. Current climate policies are projected to result in 2.7°C warming above pre-industrial levels by the end of this century and will thereby at least temporarily overshoot the Paris Agreement temperature goal.</p> <p>Here, we assess the risk of triggering climate tipping points under overshoot pathways derived from emission pathways and their uncertainties from the PROVIDE ensemble using PyCascades, a stylised network model of four interacting tipping elements including the Greenland Ice Sheet, the West Antarctic Ice Sheet, the Atlantic Meridional Overturning Circulation, and the Amazon Rainforest.</p> <p>We show that up until 2300, when overshoots are limited to 2°C, the upper range of the Paris Agreement goal, the median risk of triggering at least one element would be less than 5%, although some critical thresholds may have been crossed temporarily. However, the risk of triggering at least one tipping element increases significantly for scenarios that peak above the Paris Agreement temperature range. For instance, we find a median tipping risk in 2300 of 46% for an emission scenario following current policies. Even if temperatures would stabilize at 1.5°C after having peaked at temperatures projected under current policies, the long-term median tipping risks would approach three-quarters.</p> <p>To limit tipping risks beyond centennial scales, we find that it is crucial to constrain any temperature overshoot to 2°C of global warming and to stabilize global temperatures at 1.0°C or below in the long-term.</p>

<p>Floods are one of many climate change extremes causing massive economic and non-economic losses and damages. The recent 6<sup>th</sup> Assessment Report of the IPCC highlights that flooding will be more widespread at 2°C compared to 1.5°C and even more pronounced at higher levels of global warming. To prevent or reduce impacts from flooding, structural measures for flood protection through hard infrastructure are the most common intervention, as they directly manage flood hazards by controlling flow through streams and prevent water overflow. Adaptation options specifically include dikes, flood control gates, weirs, dams, storage and proper waste management.</p> <p> </p> <p>While flood protection could substantially reduce the economic costs of flood events and counts as the most effective adaptation strategy in the water sector to climate change, scenarios for future flood protection are still in their infancy. Consequently, quantitative assessments of climate change (i.e., impact models), which themselves include numerous uncertainties, cannot adequately account for adaptative flood protection in current risk assessments. We propose a Flood Protection Index (FPI) that captures the current level of flood protection across the globe using various data sources. By identifying adaptation-relevant quantitative socioeconomic variables within the framework of the Shared Socioeconomic Pathways (SSPs) and accounting for future climatic risk, we will be able to project five scenarios for flood protection alongside the SSPs. For the first time, we will show how different socioeconomic trajectories could modulate future flood impacts. These scenarios can be included in quantitative assessments of climate change and improve risk assessments in the 21<sup>st</sup> century.</p>