The Ocean’S role in miTIgating climAte change: Mechanistic understanding of the legacy of anthropogenic heat and carbon in the ocean under net-negative carbon dioxide emissions

Introduction

The ocean has absorbed vast amounts of “anthropogenic” carbon and heat (Canth and Hanth, respectively), due to humans' carbon dioxide (CO2) emissions to the atmosphere and resultant atmospheric warming. We expect absorbed Canth and Hanth to leak back to the atmosphere under net-negative emissions and atmospheric cooling. Yet, such leakage and its impact on Earth’s climate evolution are poorly understood.

Research Gap

Earth system models used for such research do not resolve the most energetic features of the ocean, that is, ocean mesoscale features that mix and transport waters across ocean regions where most of Canth and Hanth is stored. I hypothesize that mesoscale features accelerate the transfer of Canth and Hanth towards leakage sites, with potential implications for climate under net-negative emissions.

Project Overview

With the project OSTIA, I will set out to test this hypothesis. To do so, the project team will:

1. Set up an innovative tool, an Earth system model rich in ocean mesoscale features.
2. Equip the model with a novel joint modeling approach for Canth and Hanth.
3. Expose the Earth system model to a CO2 emissions scenario that is consistent with a warming target of around 1.5°C by the end of the century, includes net-negative emissions after 2050, and extends until 2300.

Expected Outcomes

Pioneering outcomes of OSTIA will be:

1. A game changer in mechanistic understanding of the legacy of Canth and Hanth in the ocean for the next 10 human generations.
2. An assessment of whether current Earth system models are fit to represent Canth and Hanth legacy effects caused by the ocean mesoscale under net-negative emissions.

Importance of the Project

The objectives of OSTIA are pressing, given that delay in ambitious action to cut CO2 emissions leads to further accumulation of Canth and Hanth in the ocean, and a reliance on future net-negative emissions in order to meet promised climate targets. A successful implementation of OSTIA will be a step change in the emerging research field of the ocean’s response to net-negative emissions.