As the hottest July on record was drawing to a close, UN Secretary-General António Guterres may have summed it up best when he declared that the “era of global warming has ended, [and] the era of global ‘boiling’ has arrived.”  

Guterres was referring to a string of weather calamities that, sadly, have been repeating themselves this summer, such as “children [being] swept away by monsoon rains, families running from the flames (and) workers collapsing in scorching heat.”  But he also could have been referring to the heating of the world’s oceans by global warming, which has brought them to a figurative ‘boil’ after centuries of fossil fuels burning and loading of greenhouse gases into the atmosphere.

Until such “global boiling” stops – on the land and in the oceans – no place will be safe from the ravages of climate change.  From record floods caused by “atmospheric rivers” of rain to displaced jet streams setting up summer-long heat waves, drought and wildfires, ocean temperatures now drive many of the world’s increasingly severe weather-related disasters.

Sea surface temperatures in the North Atlantic Ocean this summer are running 1.5°C (2.7°F) higher than the 30-year average (1991 – 2020), shattering previous records by a wide margin and entering uncharted territory.    

Beware of Warming Oceans

Ocean temperatures in places like the Florida Keys have reached hot-tub levels this summer, bleaching and killing some coral reefs completely.  Persistently high temperatures throughout the Atlantic basin have prompted weather forecasters to up the projected number of tropical storms from 17 to 21 this summer, with most of the 2023 Atlantic hurricane season still to come.

Even more worrisome is the unprecedented rate of melting of Antarctic sea ice and glacial ice on Greenland, which could increase the projected amount of sea level rise by a wide margin this century, putting billions of people and trillions of dollars of property at greater risk.

But if there is one precipitating event that has brought the Earth’s climate to a boil this summer, it is a change in ocean currents in the equatorial Pacific Ocean – a naturally recuring phenomenon known as “El Niño.”  In this ocean-circulation pattern change, a cooler La Niña phase tends to suppress global atmospheric temperatures, while El Niño exacerbates them.

The latest La Niña spanning 2015 to 2022, however, didn’t have much of a dampening effect on global temperatures.  In fact, that eight-year time span still was the warmest period in a 173-year climate dataset.  Now that these El Niño conditions have set in, the warming effect is being compounded and it’s almost certain that one of the next five years will be the hottest on record.  Even more concerning, it’s more likely than not that the global temperature increase will reach the 1.5°C policy limit that’s meant to serve as the long-term cap on warming above pre-industrial levels.

With the onset of El Niño conditions in 2023, this July shattered previous monthly temperature records by a wide margin; it may even have been the hottest month in the last 150,000 years!  Global temperatures are expected to remain elevated for at least the next 6 -12 months as this El Niño condition intensifies.   

Have our oceans reached a tipping point?

As witnessed by these record-setting weather events, our oceans may have reached a climatological tipping point this summer.  Owing to their size, circulation patterns and chemical composition, the Earth’s oceans have been absorbing more than 90% of the excess heat caused by global warming for more than two centuries.  

With the amount of greenhouse gases now loaded into the atmosphere, this heat retention is equivalent to 9,000 times the annual electricity consumption of the United States, or five Hiroshima bombs exploding every second.  If that’s too mind-blowing, imagine a 2-watt light bulb heating each square meter of the Earth each year, amounting to 350 years of global energy consumption.  

Expressed in zettajoules of heat (that’s one joule with 21 zeros behind it), the oceans’ current rate of heat absorption has grown from 9 to 14 zettajoules in just the last five years.  That works out to 28 times more heat than the 0.5 zetajoule coming from global annual energy use.  At the current rate of heat assimilation, even the Earth’s biggest thermal sink may run out of carrying capacity sometime soon, allowing global warming to move forward at a faster pace, or worse, triggering a step change that’s indicative of a tipping point (or is it a ‘boiling point’?) in the global climate system. 

Increased ocean acidification, decreased oxygen levels, dead zones, and fish and coral die-offs are just part of a long list of environmental damages that could be inflicted on the world’s oceans by continued global warming.  In this post, however, we’re focusing on four other treacherous, ocean-related climate phenomena that bear close watching in the days ahead:  

• Atmospheric rivers and flash flooding:  This year’s epic winter storms in California and this summer’s catastrophic floods in Vermont are just two of the latest examples of ocean-borne “atmospheric rivers” that have directed epic amounts of precipitation onto adjoining land masses.  As the atmosphere warms, it has a higher dew point that raises humidity levels and the content of water vapor.  With each 1°C rise in ambient air temperatures, the atmosphere’s water carrying capacity rises by an average of 7 percent.  With ocean waters now running 1.5°C warmer than normal, an ordinary rainstorm can drop 10% more rain than before, while an “atmospheric river” (which channels this rain repeatedly over the same area) can magnify this flash flooding to catastrophic effect.  In fact, severe thunderstorms this year have already contributed to a staggering $34 billion in insured property losses in the U.S., according to reinsurer SwissRe.  With the Gulf of Maine now one of the fastest-warming bodies of water in the world, severe flash flooding poses a heightened risk for our region.  Globally, extreme rainfall events that once occurred every 20 years or so now might appear as often as two to five times per decade as this new climate regime takes hold.

• Ice loss and sea level rise:  Most worrisome is ocean warming that’s happening around the Earth’s poles.  Greenland, which contains 20 feet of sea level rise in its mile-thick, ice-covered surface, has been deluged by “atmospheric rivers” of rain this year, accelerating the loss of glacial ice over its southern flank.  Even more alarming is the loss of Antarctic sea ice this summer.  Compared with 40 years of measurement data, this ice is suddenly shrinking fast.  As of the end of June, sea ice covered only 4.5 million square miles of ocean around the Antarctic continent.  That’s nearly a million square miles less than the long-term average, and almost a half a million square miles less than the record loss set last year.  In places where this sea ice disappears altogether, previously landlocked ice will be able to move off the Antarctic continent unimpeded, with 200 feet of sea level rise possible over the next several centuries, triggering mass migrations along the world’s coastlines.

• Weakening jet stream:  With pockets of warm water also moving north in the Pacific Ocean, the Arctic Ocean has also come under siege.  There, the rate of warming is nearly four times the global average.  Within a few decades, its polar ice cap could disappear entirely in summer months.  Meanwhile, the circumpolar jet stream, dividing frigid Arctic air from more temperate air in mid-latitude regions, is starting to weaken and flex.  Much like a spinning top that’s losing its centrifugal force, this counter-clockwise jet stream is wobbling and wandering more as it flows across the Northern Hemisphere.  Such a weakened flow allows cold Arctic air to plunge southward in winter months into regions not accustomed to extreme cold and snow.  Yet, in summer months, these same conditions are conducive to setting up “heat domes” over mid-continent regions, forcing weather-changing fronts to steer around them.  The frequent storms and cooler weather we’ve experienced in New England this summer is really a function of being downwind of the protracted heat dome parked over the Deep South.  

• Weakening Gulf Stream:  One of the most alarming results of these changes in global circulation patterns is what’s happening to the Gulf Stream as it flows off the east coast of the United States and across the Atlantic Ocean toward Europe.  Usually, natural convection of ocean heat allows the Gulf Stream to run much like a conveyor belt.  At its northern apex, heat convection allows colder, denser water to sink, allowing the Gulf Stream to reverse the course and head back toward the Equator.  However, as the Gulf Stream mixes with more cold, fresh water melting off the Greenland ice cap and from disappearing polar sea ice, its temperature and salinity balance is changing and this ocean circulation is being severely tested.  The consequences to northern Europe from a collapse in the Gulf Stream would be especially devastating.  The last time this happened was 12,000 years ago, when the Earth was emerging from its last ice age.  Northern Europe plunged back into another millennium of severe snow and cold until the Gulf Stream started to flow once again.  In recent years, a patch of Atlantic Ocean south of Greenland has started to cool conspicuously, creating a ‘cold blob’ that some scientists see as a sign that the Gulf Stream circulation is slowing.  A new study released this summer warns that such weakening could lead to its total collapse of the Gulf Stream this century – and even as early as this decade!  Ironically, this step change in global warming may result in drastic cooling of much of the North Atlantic region eventually.

Uncertainty over the timing of this possible collapse shouldn’t be taken as an excuse for not reducing greenhouse-gas emissions to try to avoid it, however.  On the contrary, “It is very plausible that we’ve fallen off a cliff already and don’t know it,” said Dr. Hali Kilbourne of the University of Maryland Center for Environmental Science, in a New York Times interview.  “I fear, honestly, that by the time any of this is settled science, it’s way too late to act.”

Expect the unexpected – and embracing change

So, when you put it altogether, the summer of 2023 may mark when record-setting weather events became the rule, not the exception, and the consequences of global warming are no longer found to be linear, intuitive, or even entirely predictable.  Simply put, we are entering uncharted territory.  

About the only thing we know for certain is that we’ll see more of these extreme events – and more often – until we get our emissions of greenhouse gases under control.  Despite recent progress in the transition to renewable fuels, carbon dioxide emissions from fossil fuels are still rising and have not yet reached their peak.  

Yet there are important glimmers of hope.  In a world that has relied on fossil fuels for well over a century, it is now making a quick pivot to solar and wind power, which are breaking generation records.  At the current pace of installations, renewables will overtake coal as world’s largest source of electricity by 2025.  And by 2035, many automakers aim to replace their internal combustion engine fleets with electric vehicles.  Home heating, cooling and cooking systems are also going electric over this period.

Add it all up and more than $1.7 trillion is expected to be invested in renewable energy, electric vehicles and batteries globally just this year, compared with a little over $1 trillion in fossil fuels. That is the most money ever spent on clean energy in a year, by far, according to the International Energy Agency, and it’s a trend you can follow in your own purchasing decisions!

For 15 years, Solaflect Energy has been your home energy management partner. For more information on our sun-tracking solar arrays and solar EV chargers email us or call (802) 649-3700.  Working together, we have the power to make a difference in the fight against climate change.