a bonobo humanity?

The most recent New Scientist podcast has reported from a big meetup re global warming, melting ice, disappearing islands and such, and I feel that’s something I need to know much more about. The Australian Antarctic Research Conference was just held in Hobart in late November, attended by some 500 researchers.

So here’s the grim. According to an interviewee who attended the conference, ‘there was a precipitous drop-off in the extent of the winter sea-ice around Antarctica in 2023 and again in 2024, 2024 being nearly as bad as 2023’. The 2023 data for winter sea-ice was the lowest with regard to expectations since data has been recorded. Seven standard deviations off the mean, apparently. Whateva, that doesn’t sound good. So the decrease in Antarctic sea-ice over this past decade is equivalent to that in the whole Northern Hemisphere in the past 45 years. And if those magnitudes continue, the Antarctic could be free of summer sea-ice even before the Arctic, which is expected to experience that scenario by around 2050.

So this will certainly lead to changes in ocean currents, and other mostly unpredictable knock-on effects, supposing the changes being measured down south represent something permanent. The fall in sea-ice became measurable from 2016, but has become more dramatic recently. Ice reflects sunlight back into space, so its reduction will lead to oceanic warming, which in turn will lead to a more rapid reduction of ice. One of the key areas of concern is the Denman Glacier and the surrounding Shackleton Ice Shelf, which is melting quite quickly. The complete melting of that particular system is calculated to lead to some 1.5 metres of global sea level rise (which seems hard to believe, I must say).

So what is to be done, and how are those most responsible for the global warming that’s causing all this, responding? Well, it doesn’t seem to be getting much airplay on the internet at present, and apart from New Scientist, there hasn’t been much reporting on the above-mentioned conference and its findings, so I’m having to dig deeper.

I’ve picked up a new term: the cryosphere. That’s the Earth’s icey stuff, in all its forms and habitats. And of course most of it exists at or near the Poles. The IPCC released a Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC) in September 2019, all available online, and chapter 4, ‘Sea Level Rise and Implications for Low-Lying Islands, Coasts and Communities’, is obviously of particular interest. It found that the dominant cause of the rise in global mean sea level (GMSL), at least since 1970, is ‘anthropogenic forcing’, which presumably means something like ‘humanity’s typically forceful influence’. It also found the GMSL rise is accelerating. The situation was worse in the past, though. Way back in the last interglacial, some 120,000 years ago, and also on other occasions millions of years ago, but there were a few H sapiens and other hominins around at the time of the last interglacial, and they obviously survived, so why worry?

Seriously the effects of sea level rise (SLR) on coastal communities are enormously complex and multifaceted, with human-induced habitat degradation muddying the waters of coastal ecosystems, so to speak. There are obvious reasons why humanity tends to congregate around coastal regions – and it’s particularly obvious why it happens here in Australia – and where humanity congregates in large numbers, there’s bound to be a cost, in particular to other species, with rebound effects. Here’s how the IPCC puts it:

Coastal ecosystems, including saltmarshes, mangroves, vegetated dunes and sandy beaches, can build vertically and expand laterally in response to SLR, though this capacity varies across sites … These ecosystems provide important services that include coastal protection and habitat for diverse biota. However, as a consequence of human actions that fragment wetland habitats and restrict landward migration, coastal ecosystems progressively lose their ability to adapt to climate-induced changes and provide ecosystem services, including acting as protective barriers….

Again, this doesn’t sound like deadly serious stuff, to selfish humans like us, but global SLR, estimated by the IPCC to be around 3.3 mm annually (and likely set to increase), will clearly affect islands and coastal regions worldwide. It’s also important to note that global warming isn’t occurring uniformly – Africa’s Central Sahel region, effectively the Sahara Desert, is warming at 1.5 times the global rate. War-torn regions such as Syria and the DRC are also more vulnerable to climate change. Afghanistan is now experiencing its worst drought in decades, while paradoxically there is severe flood damage in some areas. Lack of foreign aid due to the Taliban takeover has created an economic and humanitarian crisis there.

Finally, to focus more on Australia, our future scenario depends muchly on global greenhouse gas emissions, and we, globally, have done little, in spite of all the fuss, to reduce these emissions. The levels reached a new high in 2023, with CO2 ‘accumulating in the atmosphere faster than any time experienced during human existence, rising by more than 10% in just two decades’, according to a report from the World Meteorological Organisation (WMO). Sea level rise is more of a factor here than in most regions – 85% of our population now lives within 50 km of the coast. This will of course affect coastal infrastructure and our celebrated beaches, but the real issue, for Australia and elsewhere, is that the fact that previous records are ‘falling like dominoes’, according to one expert, is still not being taken seriously enough by the major contributors to the problem, both on a corporate and national level. Australia’s native islander peoples, in the Torres Strait and elsewhere, are facing threats to their very way of life due to sea level rise, but most Australians don’t feel much affected, and many are in denial about the issue, like frogs in the proverbial warming pot.

So, what more to say? It’s hard to keep watching this all happening…

References

https://www.newscientist.com/podcasts/

https://wmo.int/news/media-centre/greenhouse-gas-concentrations-surge-again-new-record-2023

https://www.rescue.org/article/10-countries-risk-climate-disaster

Sea Level Rise in Australia: Risks and Adaptation