Carlos García-Soto
CSIC (IEO) researcher, head of the Ocean-Climate System Assessment Unit, coordinator of the World Ocean Assessment (WOA, United Nations) and delegate to the Climate Change COP (UNFCCC), the Treaty on the High Seas (BBNJ) and the International Seabed Authority (ISA)
The data presented by Copernicus are robust because they come from two independent observation systems that reach the same conclusion. Furthermore, the result is consistent with what would be expected in a context of sustained ocean warming, upon which a new El Niño episode is now beginning to take effect. Rather than an isolated data point, this record should be interpreted as the result of the interaction between the natural variability of the climate system and the sustained warming of the ocean due to climate change.
These observations are consistent with a Correspondence published in Nature on 18 June, in which I argued that the main risk posed by future El Niño events may not be a more intense El Niño, but rather an El Niño acting on an ocean that has already accumulated an exceptional amount of heat. In this context, impacts such as marine heatwaves, droughts, floods, wildfires or crop losses – which traditionally tended to be more staggered over time and across regions – may occur increasingly simultaneously, placing greater pressure on ecosystems and on our societies’ capacity to respond.
This paper sets out three priorities for public policy. Firstly, to prepare to cope with simultaneous climate impacts across different regions and sectors. Secondly, to safeguard the recovery times of response systems that are already operating close to their limits. And, finally, to explicitly incorporate persistent ocean heat into climate risk planning and coordination during major El Niño events.