2021 State of the Environment Report Marine Chapter – Expert Assessment – Pressure – Climate Change – Ocean acidification

点击翻译按钮获取中文摘要

The Marine chapter of the 2021 State of the Environment (SoE) report incorporates multiple expert templates developed from streams of marine data. This metadata record describes the Expert Assessment "Pressures on the marine environment - climate change - ocean acidification". <br /> ***A PDF of the full Expert Assessment, including figures and tables (where provided) is downloadable in the "On-line Resources" section of this record as "EXPERT ASSESSMENT 2021 - Ocean Acidification"***<br /> <br /> ----------------------------------------<br /> <br /> DESCRIPTION OF PRESSURE<br /> Ocean acidification describes changes in dissolved carbonate chemistry resulting from the ocean taking up about 25% of the annual carbon dioxide (CO2) emissions. The changes include decreases in seawater pH and a lowering of the saturation state of aragonite, a major mineral form used by marine organisms to produce shells and skeletal material. The changes are rapid with the pH change being ten-fold greater than at any time in the past 300 million years (Hönisch et al., 2012). Superimposed on the large-scale change is increased variability at seasonal and local scales, particularly in coastal regions (Mongin et al., 2016; Shaw et al., 2012).<br /> <br /> DATA STREAM(S) USED IN EXPERT ASSESSMENT<br /> Offshore data from around Australia as described in Lenton et al. 2016.<br /> Lenton, A., B. Tilbrook, R. Matear, T. Sasse and Y. Nojiri (2016) Historical reconstruction of Ocean Acidification in the Australian region, Biogeosciences, 13: 1753–1765. https://doi.org/10.5194/bg-13-1753-2016 <br /> <br /> ----------------------------------------<br /> <br /> 2021 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details]<br /> <br /> • 2021 •<br /> Assessment grade: Very high impact<br /> Assessment trend: Deteriorating<br /> Confidence grade: Somewhat adequate<br /> Confidence trend: Adequate<br /> Comparability: Comparable<br /> • 2016 •<br /> Assessment grade: Very high impact<br /> Assessment trend: Deteriorating<br /> Confidence grade: Adequate high quality evidence and high level of consensus<br /> Confidence trend: Adequate high quality evidence and high level of consensus<br /> Comparability: Grade and trend are somewhat comparable to the 2011 assessment<br /> • 2011 •<br /> Assessment grade: Very good<br /> Assessment trend: Deteriorating<br /> Confidence grade: Limited evidence or limited consensus<br /> Confidence trend: Limited evidence or limited consensus<br /> <br /> ----------------------------------------<br /> <br /> CHANGES SINCE 2016 SOE ASSESSMENT<br /> More data are now available.