Quantification of ocean heat uptake from changes in atmospheric O2 and CO2 composition

Abstract

The ocean is the main source of thermal inertia in the climate system. Ocean heat uptake during recent decades has been quantified using ocean temperature measurements. However, these estimates all use the same imperfect ocean dataset and share additional uncertainty due to sparse coverage, especially before 2007. Here, we provide an independent estimate by using measurements of atmospheric oxygen (o 2) and carbon dioxide (CO 2)-levels of which increase as the ocean warms and releases gases-as a whole ocean thermometer. We show that the ocean gained 1.29 ± 0.79 × 10 22 Joules of heat per year between 1991 and 2016, equivalent to a planetary energy imbalance of 0.80 ± 0.49 W watts per square metre of Earth's surface. We also find that the ocean-warming effect that led to the outgassing of O 2 and co 2 can be isolated from the direct effects of anthropogenic emissions and CO 2 sinks. Our result-which relies on high-precision O 2 atmospheric measurements dating back to 1991-leverages an integrative Earth system approach and provides much needed independent confirmation of heat uptake estimated from ocean data.

Using otolith chronologies to understand long‐term trends and extrinsic drivers of growth in fisheries

“…, IPCC , Resplandy et al. ), snapper in NSG is the regional population that will likely be the most affected and growth may further decline or fish may shift to the cooler waters of southern Spencer Gulf.…”

“…, IPCC , Resplandy et al. ). Simultaneously, large‐scale fishing will continue to exert biological and ecological selective pressures worldwide (Swain et al.…”

“…To best anticipate and prepare for the future, external pressures on wild populations must be considered and managed collectively. Climate change will affect fish populations through predicted increases to ocean temperatures of up to 3°C by 2100 and higher frequency of extreme climate events like El Niño or La Niña episodes (Cai et al 2014, IPCC 2014, Resplandy et al 2018. Simultaneously, large-scale fishing will continue to exert biological and ecological selective pressures worldwide (Swain et al 2007, Audzijonyte et al 2013.…”

Carbon sequestration and biodiversity co‐benefits of preserving forests in the western United States

“…Along with emissions, multiple biogeophysical processes, including carbon uptake by the land and oceans and ocean heat exchange (Solomon et al 2009), influence atmospheric CO 2 (Canadell et al 2007, Le Quere et al 2018) and the integrated Earth system trajectory (Barnosky et al 2012, Steffen et al 2018. Recent measurements indicate the ocean heat uptake is at the high end of previous estimates (Resplandy et al 2018), and decreasing land carbon uptake relative to carbon emissions (Canadell et al 2007) is contributing to increasing atmospheric CO 2 and chances of climate destabilization (Barnosky et al 2012, Steffen et al 2018. Land preservation and timber harvest management (natural climate solutions) are viable options for avoiding greenhouse gas emissions and increasing the magnitude of the land carbon sink (Griscom et al 2017).…”

Defining CO2 and O2 syndromes of marine biomes in the Anthropocene

“…Attribution studies of CO 2 and O 2 syndromes in coastal ecosystems typically consider the impacts of a range of additional processes, beyond anthropogenic CO 2 and associated warming, including the consequences of local physical, biological, and biogeochemical processes (Table ; Mongin et al, ; Yu, Fennel, Laurent, Murrell, & Lehrter, ). Whilst climate change accounts for a substantial proportion of the observed change in CO 2 and O 2 in the upper layers of the open ocean (Byrne, Mecking, Feely, & Liu, ; Resplandy et al, ), watershed and metabolic processes account for much of the CO 2 , pH, and O 2 change in coastal ecosystems (Table , e.g., Chesapeake Bay; Cai et al, ; Li, Li, & Kemp, ).…”