Krill: tiny but important

Tipping into the unknown

Staggering temperature rises in the Antarctic should serve as an urgent warning, writes Eddie Ford

Two years ago at the coldest place on our planet, scientists at a research station on the east Antarctic plateau documented a “mind-boggling” event - the largest jump in temperature ever measured at a meteorological centre on earth, with the region that day experiencing a rise of 38.5°C above its seasonal average.1 The scientists themselves could hardly believe what they were seeing on their instruments, confronted by something completely unprecedented.

The implications are terrifyingly obvious. In sub-zero temperatures such a massive leap is tolerable, at least for humans, but imagine what would happen if we had such a rise in a country like the UK right now - on a spring day that would take the temperature to well over 50°C, which would be deadly for the population. The human body is not able to function in such heat because its natural cooling system experiences failure and everything starts to shut down. Chemical processes start to be affected, the cells inside the body deteriorate and there is a risk of multiple organ failure. The body cannot even sweat at this point, because blood-flow to the skin stops, making it feel cold and clammy. Unable to cool down, you start to fry in your own body - to the point where immersing yourself in ice water does not help. In other words, at such temperatures human life becomes impossible and it would be a catastrophe for the local ecosystem. We all go down.

What appears to be happening is that poleward winds, which previously made few inroads into the atmosphere above Antarctica, are now carrying more and more warm, moist air from lower latitudes - like Australia - deep into the continent, thus the dramatic polar ‘heatwave’ that hit the eastern Antarctic (which includes the continent itself, the ice shelves and the ocean immediately beyond).

Ominously, this staggering temperature hike is not an isolated or freak event. Over the past two years, there have been growing numbers of reports about disturbing meteorological anomalies on the continent. Therefore, amongst many things, glaciers bordering the west Antarctic ice-sheet are losing mass to the ocean at an increasing rate - while sea ice levels, which cover the oceans around the continent, have contracted dramatically, having remained stable for more than a century. The Antarctic was once thought to be too cold to experience the early impacts of global warming, but not any more - it too is succumbing rapidly to the soaring levels of greenhouse gases that are being pumped into the atmosphere through human activity.

Regime shift

Anyhow, these dangers have been recently highlighted by a team of scientists at the University of Tasmania in a paper that was published last week in the Journal of Climate. After a detailed examination of recent changes in sea ice coverage in Antarctica, the group concluded there had been an “abrupt critical transition” in the continent’s climate that could have profound repercussions for both local ecosystems and the global climate system.

What this transformation appears to mean is a regime shift in the southern oceans to a new sea-ice state. So it was actually the case that the Antarctic sea-ice coverage actually increased slightly in the late 20th and early 21st century, only to fall off a cliff in the middle of the last decade - a harbinger of the new Antarctic climate system that has disastrous implications for the region and the planet as a whole. Unfortunately, the continent is now effectively catching up with the Arctic, which until now has experienced the most dramatic impacts of global warming - warming at four times the rate undergone by the rest of the planet. But the Antarctic is already warming twice as quickly as the planet overall and that trend appears to be escalating.

Polar hits

A central reason why both the Arctic and now Antarctic are taking disproportionate hits from global warming is because the earth’s oceans - through global warming - are losing their sea ice at their polar regions. Therefore the dark waters that used to lie below the white ice are being exposed and solar radiation is no longer reflected back into outer space - rather, it is being absorbed by the sea and further heating the oceans in a vicious cycle of warming.

As the polar ice melts and contracts, there will be direct consequences both for global temperatures and, of course, rising sea levels. Bangkok, Amsterdam, Ho Chi Minh City, Manila, Cardiff, New Orleans, London, Shenzhen, Hamburg and Dubai all face inundation.

How exactly will incredible temperature rises like 38.5°C in Antarctica affect global weather and global climate patterns? Interestingly, scientists say they have not yet gathered enough data about Antarctica to give you what they would view as reliable modelling to enable accurate predictions - more a rough and ready approach at the moment. The continent is so remote and hostile that the records are comparatively sparse and therefore fail to capture all of the complex physics, chemistry and biology.

When it comes to wild life, there are not only the magnificent emperor penguins, there is the humble algae which grows under and around sea ice in west Antarctica. This is starting to disappear, with very alarming implications. Algae is eaten by krill - the tiny marine crustaceans that are one of the most abundant animals on the planet and which provide food for predators that include fish, penguins, seals and whales. Clearly, if krill start to disappear in the wake of algae, then all sorts of disruption to the food chain will follow.

However, the threat posed by the disappearance of krill goes deeper than that. It plays a key role in limiting warming in a way akin to the reflective white ice sheets. Algae absorb carbon dioxide. Krill then come along and eat them and excrete it, the faeces sinking to the seabed and staying there - acting like a like a conveyor belt that takes carbon out of the atmosphere and carries it down to the deep ocean floor, where it is locked away. Conversely, decreased levels of algae and krill mean less carbon from the atmosphere deposited on the ocean floor, and more remaining near the sea surface and returning to the atmosphere.

Another vicious feedback system that could have all sorts of other knock-on effects for any attempt to cope with the impact of global warming - one scary scenario after another.

Uncharted territory

Alas, yet another global heat record was notched up this week. According to the European Union’s Copernicus Climate Change Service, global surface temperatures in March were 0.1°C higher than the previous record for the month - set in 2016 - and 1.68°C higher than the pre-industrial average. This is the 10th consecutive monthly record in a warming phase that has shattered all previous records. Over the past 12 months, average global temperatures have been 1.58°C above pre-industrial levels - which at least temporarily exceeds the 1.5°C benchmark set as a target in the Paris climate agreement. Of course, that target will not be considered breached unless this trend continues on a decadal scale.

But this new record is enough to trigger fears that, if temperatures do not stabilise or fall by the end of August, then the world could be moving into “uncharted territory” - tipping into a new phase of even faster climate change. As noted by the UN’s Intergovernmental Panel on Climate Change, our planet has been warming at a pace of 0.3°C per decade over the past 15 years - almost double the 0.18°C per decade trend since the 1970s. The scientific debate, however, is about whether this is within the range of climate variability or a signal of accelerated warming. But the signs are not good - temperature records are being broken each month by up to 0.2°C, with many scientists admitting that no year has confounded their predictive capabilities more than 2023.

There are several possible explanations for this anomaly, if that is what it is. The El Niño effect, of course, plus reductions in cooling sulphur dioxide particles due to pollution controls, fallout from the January 2022 volcanic eruption in Tonga, and the ramping up of solar activity in the run-up to a predicted solar maximum. But, based on various preliminary analyses, these factors do not seem sufficient to account for the 0.2°C increase. We are stumbling in the dark.

Having said that, there is a 99.9% scientific consensus that human-made global warming is the cause - we are not dealing with some long-term natural changes in the climate, as a largely crank minority argue. This is the action of humanity - crucially the action of the advanced capitalist countries and now China, the ‘workshop of the world’. Meanwhile, in Britain we have the Tory government committed to ‘maxing’ out North Sea oil and gas, whilst the US is boosting and boosting again its production of shale oil.

All in service of a capitalist system that can only live by extracting ever more surplus value from workers and exploiting the wealth of nature without regard or limit. It is a system of expansion for the sake of expansion.

  1. theguardian.com/environment/2024/apr/06/simply-mind-boggling-world-record-temperature-jump-in-antarctic-raises-fears-of-catastrophe.↩︎