Humanity has a blind spot when it comes to the role of the ocean in climate change. That is in part because, as land-dwellers, we naturally tend to focus most on terra firma. But it is also because we know little about what is happening below the surface of the ocean at any moment due to a severe lack of observations there.
Satellites surround our planet and watch its atmosphere and land continuously. Every day, this gives us access to hundreds of terabytes of data on atmospheric and surface conditions.听But satellites can鈥檛 peer听into听the ocean. In comparison, we have thousands of times less data from beneath the waves, and the number of some of our most critical instruments for monitoring the depths is .听So at the time when we need real-time information from the ocean more urgently than ever, we have a diminishing amount of it.
This leaves a gaping hole in our readiness to respond to climate change. The ocean has been protecting us from the worst impacts of human-generated emissions for over a century. It has absorbed more than 90 per cent of the heat and 30 per cent of the carbon dioxide we have produced. But that has come at a cost and the ocean is spiking temperatures, rising sea levels, acidification and low-oxygen zones.
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The ocean keeps taking us by surprise. It is changing more rapidly than our models suggested it would, and that is of great concern because it drives the climate we experience on land, both in terms of heat and precipitation. Many extreme weather events also have their genesis in the behaviour of our warming ocean.
A warmer, more acidic and lower-oxygen ocean also means increasingly inhospitable environments for sea creatures. Those that can鈥檛 move elsewhere will dwindle and may disappear. Those that can move, will do so, but this will leave some places with changed听ecosystems. We are beginning to see significant groups of marine life migrating poleward , which has far-reaching implications.听Two billion people around the world as their primary source of protein.
So we must immediately and radically scale-up ocean data collection. Doing so would mean not only that we can plan solutions for the coastal regions at greatest risk of flooding and the marine life most likely to be affected, but it would also mean that we could predict and prepare for changes that will affect land climate.
There are precedents for how to do this. The 听programme shows a possible future for ocean science. It is an international collaboration among 26 nations collecting marine information using a fleet of robotic instruments the size of golf bags that drift with ocean currents. It is now the most abundant source of underwater temperature and salinity profiles in the ocean, and it makes its data available to scientists around the world within 24 hours.
Argo data has, for example, proved that the Arctic is now warming after a decade-long spell of cooling, and that this is caused by warm and saline waters spreading from the western subtropics.听It has shown that the entire ocean is warming, not just the surface. Hurricanes draw their energy from heat of the upper ocean, so Argo deploys听floats in the tropical ocean during cyclone season to aid in forecast.
This is just one example of what we can do with adequate resources.听Expanding such observations, as well as adding those important to life in the ocean and its biodiversity, is also key. Ocean observation technology provides critical evidence, but it urgently needs more money.
At the end of this month, negotiators from almost every nation on Earth will descend on Dubai for 听the COP28 climate summit.听My , Scripps Institution of Oceanography at the University of California San Diego, and the Woods Hole Oceanographic Institution in Massachusetts are the lead sponsors of COP28鈥檚 hub of ocean expertise, known as the Ocean Pavilion.听Along with our other partner bodies, we are presenting the Dubai Ocean Declaration at COP28. This calls on world leaders to support and foster efforts to greatly expand and improve ocean observations worldwide, with a particular emphasis on building capacity in island and developing nations and on expanding coverage of under-observed regions.
When, in Dubai, the parties formally review the state of the climate, they must include the ocean, and they must enable us to expand our toolkit to monitor it. Every country, every corporate enterprise and every individual has a vested interest in understanding that we must protect the sea, as it has been protecting us.
Those with power and influence should look to marine science and observation technology for a great opportunity to make a meaningful difference in tackling climate change. Understanding what is happening within the ocean is no longer optional.
Margaret Leinen is an award-winning oceanographer who is vice chancellor for marine sciences at the University of California San Diego and director of Scripps Institution of Oceanography. She is also co-chair of the Decade Advisory Board for the
