Climate Change and Its Impact on the Ocean

Abstract

Increased human activities—in particular energy generation and land use—have led to atmospheric pollution by the significant emission of greenhouse gases such as carbon dioxide (CO2) and methane. The associated climate change is also affecting the ocean while, at the same time, the ocean plays a fundamental role in mitigating climate change by serving as a major heat and carbon sink. We highlight some of the most salient aspects of climate change impacting the ocean as articulated in the Special Report on the Ocean and Cryosphere in a Changing Climate by the Intergovernmental Panel on Climate Change (IPCC) released in 2019. It shows that the ocean is warming, the global sea level is rising, ocean heatwaves are more frequent, the ocean is becoming more acidic, marine ecology is shifting, levels of dissolved oxygen are reducing and the melting of ocean-terminating glaciers and ice sheets around Greenland and Antarctica is rapidly increasing. From the perspective of meeting the United Nations Sustainable Development Goals, in particular SDG 14, there are strong synergies between promoting climate mitigation and adaptation strategies, which are enshrined in SDG 13 and outlined in more detail by the Paris Agreement. Scientific research and solution-oriented knowledge generation require the growth and transformation of the science system. Specifically, they will require more freely shared ocean data, new and more effective ways of analyzing observational data fused with ocean and climate models, and enhanced timely assessment, predictions and scenario development of future ocean conditions. At the same time, knowledge from natural and social sciences, as well as informal knowledge, must be considered. Ocean science must be in a position to support decision makers by providing knowledge and frameworks to weigh the ecological, environmental and human impacts with an expected increase in use of the ocean for different sustainable development pathways. In recognition of this challenge, the United Nations declared 2021–2030 as the Decade of Ocean Science for Sustainable Development in order to advance “the science that we need for the ocean we want”. The ocean decade seeks to catalyze a change towards more international, shared and solution-oriented ocean science.