Zoogeography of the Oceans and Climate Change PDF

Marine Biology and Conservation Zoogeography of the Oceans and Climate Change Part 2 AMOC Gulf Stream BI2MBC1 Autumn 2024 Dr Graham Lu Ocean warming affects fun...

Marine Biology and Conservation Zoogeography of the Oceans and Climate Change Part 2 AMOC Gulf Stream BI2MBC1 Autumn 2024 Dr Graham Lu Ocean warming affects fundamental physico-chemical properties of the ocean water. Ice melts. Land and sea ice melts raise sea level.  Ice melt If all glaciers and ice sheets melted, global sea level would rise by more than 195 feet (60m). https://sealevel.nasa.gov/understanding-sea-level/global-sea-level/ice-melt/  What is happening, and why? Arctic Sea Ice cover shows precipitous drop. White ice reflects heat from the sun. Additional 7cm sea level rise by 2100 from Greenland ice  See slide notes for AMOC Refs Atlantic Meridonal Overturning Circulation (AMOC) Warm surface water from tropics goes north (Gulf Stream), cold dense polar water sinks and goes south. Melt water is low salinity reducing density. Crucial for oxygenation and nutrient upwellings Disruption would have devastating zoogeographical consequences  What exactly is happening? Rare extreme event 25th Feb 2018 Strong, warm Gulf Stream => Warm air incursion over North Pole created temperatures above 0oC, comparable to parts of UK. North Pole 25-30oC warmer than expected. Note other areas – land and sea – have anomalies https://climatereanalyzer.org/reanalysis/daily_maps/ Air Temperature Map 2m above surface Climate change driven AMOC northerly current heating – Hurricanes with increased rainfall “The catastrophic rains accompanying Hurricane Florence along the U.S. East Coast can be blamed squarely on climate change….. The rainfall was projected to be more than 50 percent worse than it https://www.nationalgeographic.com/e would have been without global nvironment/2018/09/hurricane-florenc e-rain-climate-change-science/ warming...”  Climate change driven Oceanographic effects – m a d a e Hurricanes and increased rainfall n a i c u r r h t g h ? “The catastrophicu g r n rains i d s h o a i o o Florence r T accompanying r p Hurricane e es , g o f the / gU.S. iEast c l Coast can be s e along i n d veh a u i l u esquarely P b blamed e r , on climate f r t u t o r u c change….. r i n t s The rainfall was projected to be more o t p fr a fo i n on e d than 50 percent worse than it r b a g https://www.nationalgeographic.com/e a would have been without global nvironment/2018/09/hurricane-florenc c m is of da e-rain-climate-change-science/ warming...” s a l o Ocean warming affects fundamental physico-chemical properties of the ocean water. Expansion. Heat stored in the ocean causes its water to expand, which is responsible for one-third to one-half of global sea level rise.  “Greenland's ice sheet is currently 1.9 miles thick and contains enough ice to raise global sea levels by about 25 feet in all.” 2017 ttps://www.bbc.co.uk/news/science-environment-51097309 https://ss2.climatecentral.org/#11/51.48 16/ (choose a location..)  Combining Temperature Rise with Pollution Warming seas, coupled with run off pollution (agricultural fertilisers) and organic pollution (sewage, animal waste): Harmful Algal Blooms (HABS) Early / late / abnormal phytological blooms can have large trophic and/or Toxic effects “the survival of the larval fish depends on the timing of the local spring bloom of phytoplankton.” Nature 423; 398-399 (2003) NB. Refer to Dr Renee Lee’s lecture