We will summarize the following paper on effects of climate change on the global oceans then invite audience discussion of possible solutions.
Upper Ocean Temperatures Hit Record High in 2020.
ADVANCES IN ATMOSPHERIC SCIENCES, VOL. 38, APRIL 2021, 523–530
Lijing CHENG et. al.
“The long-term warming of the ocean is a critical indicator of both the past and present state of the climate system. It also provides insights about the changes to come…It is well established that the emission of greenhouse gasses by human activities is mainly responsible for global warming since the industrial revolution…[with] increased concentration of heat-trapping greenhouse gases in the atmosphere has interfered with natural energy flows. Currently there is an energy imbalance in the Earth’s climate system of almost 1 W m−2…. Over 90% of this excess heat is absorbed by the oceans, leading to an increase of ocean heat content (OHC)….
“A series of marine heat waves developed in the northeast Pacific Ocean within the past decade. The whole ocean food web was severely impacted during these extremes … according to stock assessment data, the level of mature, spawning cod was halved in the Gulf of Alaska from 2014 to 2017 ….
“By uptaking ~90% of anthropogenic heat and ~30% of the carbon emissions, the ocean buffers global warming …. However, the associated ocean response also poses a severe risk to human and natural systems. … the excess heat already in the ocean, and heat likely to enter the ocean in the coming years, will continue to affect weather patterns, sea level, and ocean biota for some time, even under zero carbon emission conditions…. The stronger ocean warming within upper layers versus deep water has caused an increase of ocean stratification …. With increased stratification, heat from climate warming less effectively penetrates into the deep ocean, which contributes to further surface warming. It also reduces the capability of the ocean to store carbon, exacerbating global surface warming …. Furthermore, climate warming prevents the vertical exchanges of nutrients and oxygen, thus impacting the food supply of whole marine ecosystems….”