Almost all of the extra heat that humans have captured by adding greenhouse gases to the atmosphere over the last few centuries has wound up warming the deep oceans. But in the fine balance that runs between the ocean depths and the atmosphere, the effects of centuries of dissipated industrial living, we are seeing the beginnings of the the next couple of centuries of extreme weather. We’re now starting to feel the effects of that excess heat.
The Guardian has had several articles detailing the downstream effects of warming the oceans.
The temperature at the ocean’s surface – like on land – is being pushed higher by global heating but can jump around from one year to the next as weather systems come and go.
But in the 2km below the surface, that variability is almost nowhere to be seen. The rising heat down there has been on a relentless climb for decades, thanks to burning fossil fuels.
“The heat-holding capacity of the ocean is mammoth,” says Dr Paul Durack, a research scientist specialising in ocean measurements and modelling at the US Department of Energy’s Lawrence Livermore National Laboratory.
“The ocean captures more than 90% of the imbalance of energy that we’re creating because of anthropogenic climate change.”
The ocean is much less reflective than the land and soaks up more of the direct energy from sunlight.
But as greenhouse gases trap more of the energy that’s reflected back – allowing less to escape to space – the ocean tries to balance itself with the heat in the atmosphere above.
A technical chart in a chapter of the latest UN climate assessment laid out the unfathomable heat gain. Between 1971 and 2018, the ocean had gained 396 zettajoules of heat.
How much heat is that? Scientists have calculated it is the equivalent energy of more than 25bn Hiroshima atomic bombs. And that heat gain is accelerating.
A study in January found the ocean gained 10 ZJ more in 2022 than the year before – enough heat to boil 700m kettles every second.
Compared with the ocean, according to a study in January the atmosphere has held on to about 2% of the extra heat caused by global heating since 2006.
To understand what’s happening below the ocean surface, out of sight of satellites, scientists look at a vast network of thousands of thermometers on buoys, ships, underwater gliders and permanent moorings.
Durack says it wasn’t until the early 2000s that a view of the changes in the ocean – long-predicted by climate scientists – started to become clear as more and more data became available.
We have heated the oceans enough now that we’re getting very strong climatic shifts not merely predicted, but now thoroughly measured at the surface of the oceans and into the atmosphere. Not just the wind and rain that has been shaking my top story ridge apartment since October.
In Asia the tropics are getting quite extreme heat.
Asia is experiencing weeks of “endless record heat”, with sweltering temperatures causing school closures and surges in energy use.
Record April temperatures have been recorded at monitoring stations across Thailand, Myanmar, Laos and Vietnam, as well as in China and South Asia.
On Tuesday, four weather stations in Myanmar hit or matched record monthly temperatures, with Theinzayet, in eastern Mon state, reaching the highest, at 43C (109.4F). On Wednesday, Bago, north-east of Yangon, reached 42.2C, matching an all-time record previously recorded in May 2020 and April 2019, according to Maximiliano Herrera, a climatologist and weather historian.
“The poorest of the poor are going to [suffer] the most. Especially, it is devastating for the farming community, the people who are dependent on agriculture or fishing,” said Dr Fahad Saeed, regional lead for South Asia and the Middle East at Climate Analytics, a climate science policy institute.
“The heat is not foreign to this part of land,” he said, but added that temperatures were rising beyond the limits of people’s adaptability.
Note the emphasis on farming, agriculture and fishing. These are the underpinnings of our societies worldwide. They are extremely sensitive to weather and climatic shifts. Our food gathering technology systems worldwide are inherently dependent on having predicable weather and climatic patterns. Not something that has been noticeable in NZ this year, or in Australia over their last decade of drought and floods, or in large parts of Asia this yera.
A lot of that is directly related to shifts in the El Niño and La Niña climatic pattern in the Pacific. The recent changes since 1960 in the El Niño-Southern Oscillation (ENSO) are now definitely attributable to the greenhouse gas emissions.
A new study led by researchers at CSIRO set out to determine the impact of greenhouse gas emissions on the major climate driver, known as the El Niño-Southern Oscillation (ENSO).
Up until now there had been limited understanding about the role climate change has already played on ENSO, with research primarily looking at future projections.
Lead researcher Wenju Cai said their research yielded significant results, with evidence that El Niño and La Niña events had become more frequent and intense due to increasing emissions of greenhouse gases.
“Previous research projected how El Niño and La Niña will change in the future but was unable to tell whether human-caused climate change has already affected [them],” he said.
“The current paper provides modelling evidence that climate change has already made El Niño and La Niña more frequent and more extreme.”
The swinging pendulum of ENSO plays a major part in year-to-year climate, with recent La Niña and El Niño events having played a hand in devastating flooding and drought events in Australia.
On a global scale, no other single phenomenon yields a bigger influence on whether a year will be warmer, cooler, wetter, or drier than average.
It is a climate pattern that has been operating for millions of years, according to palaeoclimatic evidence.
The CSIRO study, published in the journal Nature Reviews Earth and Environment, examined extensive outputs from models without greenhouse warming, each for hundreds to over thousands-of-year time scales, to examine how unusual the last 60 years have been.
To understand the change, they then compared ENSO in the 60 years pre- and post-1960.
They found that strong El Niños increased from two events in the pre-1960 to four events in the post-1960, and strong La Niñas from one event to nine events.
Dr Cai said the observed strength was extremely unusual if climate change had not had an impact.
Even without changes to ENSO itself, Dr Cai said the impacts of El Niño and La Niña were expected to be more intense because of climate change.
“Global warming makes their impact more extreme because a warmer atmosphere holds more water, so when it rains it rains harder, and evaporation is higher making droughts more severe, their onsets earlier and harder to get out,” he said.
But Dr Cai said with the changes to the frequency and strength of ENSO the impacts were likely to be even stronger.
The recent years of overheated surface waters around NZ, probably as a result of the last 3 years in a La Niña pattern tend to drive home just how extreme this is likely to be – even here. New Zealand is an island nation, well separated and ocean buffered from any disturbing continental land mass. But the ocean heatwaves around us have been devastating to our marine ecosystems, and to the large fishing and aquaculture industries.
New figures provided to the Guardian by scientists studying ocean temperature shifts show that on average, over the year to April 2023, New Zealand’s coastal waters sat stewing in marine heatwave conditions for 208 days. Some southern regions experienced marine heatwave conditions for more than 270 days during the period. In the north island’s Bay of Plenty, the waters remained in heatwave for an entire year.
With little respite for species to recover between the waves of heat, scientists warn that some ecosystems are reaching tipping points under the surface, with effects that will be felt years into the future. No one yet knows what it will mean for the fish, seabirds, whales, dolphins, and New Zealand’s multi-billion dollar fishing industry.
As scientists and communities begin to reckon with the impact, the conditions hitting Aotearoa provide a preview of the future of the world’s oceans under climate change: waters around the world are projected to rise by about 4C on average by 2100, if the world maintains its course on global heating. Heatwaves around New Zealand are already seeing spikes that high, giving a glimpse of what it can do to species under the surface.
Some of the examples provided are pretty gruesome, with massive wash ups of dead fish, starving penguins, sea sponges bleaching in Fiordland as their algae cooks off, plus fish species and whales disappearing to more benign ocean climates. But it also affects our economy.
The changes in the ocean are so stark they have been noticed outside scientific circles.
In the hills above Blenheim, between the wineries and pine plantations, trucks rumbled through January along the narrow road. They would make the journey 160 times over, through the hot summer months, winding from the coast to the hill and back again. Their cargo was tonnes upon tonnes of fish: king or “chinook” salmon, the most expensive variety of the salmon family, prized enough that a single large fish can sell for up to $1,700.
Usually, it would be sliced into sashimi, or smoked and laid atop hors d’oeuvres. Instead, it lay rotting in the truckbeds, more than 1,300 tonnes of it, carried to be dumped in a pit in the hills.
In Marlborough’s fish farms last year, the fish had died in their thousands, unable to survive the rising temperatures around them. In warmer areas, about 42% of total fish stock died. The country’s largest salmon producer, NZ King Salmon, announced it would have to shut down some of its farms as the climate heated waters around the sounds.
“When I joined this company, I never heard of the term ‘marine heatwave’,” said CEO Grant Rosewarne, as the company reckoned with the losses. “Recently, there’s been three of them.
“We thought we had more time,” he said. “Climate change is a slow process. But faster than many people think.”
New Zealand’s seafood industry plays a key role in the economy, contributing around $2bn in export earnings and employing more than 13,000 people. As sea temperatures warm, they are wreaking havoc with some of the most profitable sections of that industry.
“There’s been definitely changes with marine fisheries – with a lot more warmer water fish being caught further south,” Langlands says. “I really do feel fear. And feel for the price of seafood in New Zealand.”
That stored ocean heat isn’t just going to affect the ocean. What happens in the oceans directly affects what happens on land and especially in New Zealand. Farmers and urbanites can expect to feel the effects in the short-term over the next decade or so.
This has been easy to observe in the tail end of our last few years of a strong La Niña and its associated devastation in the upper North Island down to Hawke’s Bay, East Cape and Poverty Bay. It included my car getting written off after traversing the St Georges Bay Road River in downtown Auckland. That was rather surreal as the storm water system started blowing its access lids and the rapidly rising waters.
As well as drowning cities, towns, and farmlands, it also demonstrated that our infrastructure was built for a different era – that of the climate we used to have. This plaintive article in the wake of the devastating Cyclone Gabrielle flooding in February was pointing to the once in 250 year flood in Napier in 2020.
It was meant to be a one-in-250-year deluge but the last big floods in Napier, and the recommendations that followed, were a little more than two years ago.
“In the context of climate change, events such as the November flood may become more common, and Napier should expect and prepare for extreme weather events in the future with changing weather patterns meaning extreme weather events will return on a shorter cycle than they once did,” a Napier City Council 2021 report said.
Nobody died in the November 2020 floods but a report to the council a year later shows it resulted in 173 evacuees, 115 homes deemed uninhabitable, and 2680 homes losing power.
The rainfall was a one-in-250-year event, the report said, but warned “events of this nature, and subsequent flooding, may occur more often”. Other reports downgraded it to once in a century.
Fast-forward 827 days to Valentine’s Day, February 2023 and Cyclone Gabrielle delivered what Prime Minister Chris Hipkins said was “the most severe weather event this century”, submerging a Hawke’s Bay power station, flooding homes to their roofs, killing at least seven in Hawke’s Bay, and creating thousands of evacuees and many unaccounted for.
Multiply that by every city, town, and farmland region in NZ. Look at all of the roads, rail, water systems, power and telecoms and buildings that were and often still are being built for the climate of the last more benign century. Like Napier, instead of all of that infrastructure being tested by weather to see if it fit for purpose every few centuries, now with a changing climate it is likely to be tested within a decade.
This makes it easier to understand why this years infrastructure budget (and the budgets over the last 5 years) have been so enormous. We’re not only having to catch up for the later 50 odd years of laggard investment in infrastructure, mostly by the conservative governments and councils, we’re having to build for ever-more likely devastating weather events.
National and Act of course are vaguely hand-waving that they may have policies to deal with this. None of which appear to have any more substance or detail than simpleton slogans. The reality is that they are both solidly stuck in ideologies of the 20th century – because they’re conservative, obsessed by making sure that the wealthy aren’t taxed, inefficiently chasing the poor with punitive and inefficient policies guided more by slogans than intelligence, and generally pretty damn stupid about dealing with any kind of change. You’d think that they never left the last century when you listen to them.
Quite unlike the budget yesterday. Like the 3 Waters programme, it probably isn’t enough. But at least it is a step in the right kind of direction to deal with the already existing build up of heat in the oceans.
Don’t forget that El Niño is currently slated to become dominant and active in 2023/2024. Based on what has happened in recent El Niño events it will arrive early, bigger and more destructive than expected, and cause more but different events than La Niña. Instead of just heat, wind and rain we get more atmospheric cooling from the south (quite different effects than most of the world). It will probably take a year or two to really hit here. But it is likely to be much more extreme that previous events.
A big part of the government’s recovery and resilience thrust is its focus on infrastructure.
Robertson said: “The government has taken significant steps to address New Zealand’s infrastructure deficit. We have committed $71 billion of infrastructure investment over the next five years in addition to the $45 billion we have spent on infrastructure in the past five years. This is the funding that builds our schools, hospitals, public housing, [and] rail and road networks.
“In the last term of government we set up the Infrastructure Commission/Te Waihanga, which developed the New Zealand Infrastructure Strategy, identifying the challenges New Zealand is facing over the next 30 years. We know we need to change how we think about infrastructure planning and resourcing.
“Alongside this Budget, we have released our Infrastructure Action Plan, which supports our response to the strategy and which is crucial to continuing to deliver the infrastructure transformation required while providing certainty to the construction sector.”
The Minister pointed to the need to future-proof the infrastructure in New Zealand for the country’s growing and changing population, climate change events, and to make use of the available developing technology.
“The North Island weather events added a level of urgency to our infrastructure investment planning and highlighted the importance of resilience in the face of climate change and increasing extreme weather events,” Robertson said.
“Today I am announcing a major change in how we address our infrastructure deficit and build a more resilient nation. Through Budget 2023 we are investing $6 billion in the initial phase of a National Resilience Plan. This will support medium- and long-term infrastructure investment and focus in the first instance on building back better from the recent weather events.”
According to the Minister, the initial focus of investments will likely be on road, rail, and local resilience. Additionally, telecommunications and electricity transmission investment is high on the agenda as well.
Robertson said: “As indicated at Budget 2022, the change to the fiscal rules means we can use our balance sheet more effectively to support long-term productive investments such as this programme.
“For too long governments have kicked the can down the road when it comes to investing in resilient and essential infrastructure investment. Today we embark on the long-term nation-building that I believe a responsible government must do.”
Outside this morning, I hear the Auckland Central fire-engines, police, and probably ambulances sirens going their way past, as they were doing through the evening and this morning. Presumably dealing with the consequences of last nights weather…. It was certainly shaking my apartment when I was writing the start of this post last night