Business on the Edge 2024

What is it? Deep ocean currents are driven by differences in the density of ocean water. This is controlled by temperature and salinity. The input of freshwater from melting land ice, the reduction in sea ice extent and the warming of ocean water all change the density of ocean water, affecting the rate at which deep ocean water circulates. The Labrador-Irminger Seas convection is at particular risk of collapse due to warming polar regions. If global temperatures continue to increase, the Atlantic Meridional Overturning Circulation (AMOC) will also be at risk of collapse, with global implications. What are the implications? Increased frequency and intensity of extreme weather events in Europe. Drop in temperature in northern Europe, but extreme heat elsewhere. Possible disruption of precipitation patterns, which have an impact on food productivity (e.g. in India, South America, West Africa). Rising sea levels on the eastern coast of North America, leading to coastal flooding.Temperature scenario Labrador & Irminger Seas convection collapse Atlantic Meridional Overturning Circulation (AMOC) collapseScientific confidenceRelated Earth system tipping points Where does it occur?1.1 – 3.8ºC 1.4 – 8.0ºCHigh Low Labrador & Irminger Seas convection collapse/uni00A0 AMOC cessation Shocking scientific factWhat could happen? Further currents weakening –Under continued high emissions, the AMOC would decline 74% by 2290–2300, with a 44% likelihood of outright collapse. –This would amplify regional consequences, such as sea level rise, disruption of rainfall patterns, increased storms and temperature drops. Shift of the rainfall zone –Major rainfall zones would shift due to AMOC collapse, leading to less rainfall over Europe, North and Central America, North and Central Africa and Asia, causing drought conditions. –AMOC collapse would return the rain belt to the equator, causing droughts and fires in tropical forests. Socio-economic consequences 1 A weak AMOC will not only affect food security but also the livelihoods of communities dependent on these industries. AMOC collapse will therefore lead to a substantial reduction in global economic output and exacerbate global economic inequalities. 2 Instability of the AMOC would have a huge impact on agriculture, especially in Europe. If the AMOC weakened or collapsed in the coming decade, Europe’s seasonality would strongly increase. This, in turn, would lead to harsher winters, and hotter and drier summers. This shift in Europe’s climate is projected to reduce agricultural productivity and render most land unsuitable for arable farming. 3 In the tropics, collapse of the AMOC would cause a shift of the monsoon rains in central/southern America, West Africa, South Asia and India. This will have major impacts on vegetation productivity, including crop productivity, with significant decreases in these regions.Increased GHGsGlobal warmingLoss of underwater speciesChanges to heat, water and nutrient distribution Increased influx of freshwater from melting iceDisruption of precipitation patterns Sea level rise Coastal erosionNetwork diagramOcean circulation Related climate hazards Extreme heat Drought WildfireCoastal flooding Fluvial floodingWater stress The circulation of the Atlantic Ocean is heading towards a tipping point: AMOC has declined 15% since 1950 and is in its weakest state in more than a millennium – it has the potential to collapse, with catastrophic consequences. Sea ice lossDisruption of Atlantic Ocean circulation Land ice lossIce sheet destabilizationOcean warmingFIGURE 10 | LANDSCAPE BRIEF Business on the Edge: Building Industry Resilience to Climate Hazards 21