As a gardener, I’ve noticed one of the features of this summer’s El Nino pattern has been the greater than normal differences between daytime highs and nighttime lows. I came across a comment on social media a while back saying that a bigger than normal variation in temperature across 24 hours can damage plants. Googling just now to see the science on that, I didn’t find much because most of the hits were about how much plants depend on temperature change within certain ranges simply to function.
It seems prudent to consider that in addition to extreme weather events, climate change may be pushing local temperatures outside the norm of what makes food growing possible, even in temperate climates like New Zealand. We know that mono-cropped industrial grains and legumes are already at risk of failing significantly enough to cause widespread hunger and starvation as well as price spikes, civil unrest and war. Under the circumstances, it stands to reason, or the precautionary principle, to protect food growing with everything we’ve got. There is no future of magic domes and hydroponics if the global economy crashes fast or the countries with the biggest stick start invading stable growing climates for food resources. Or we become so overwhelmed with climate events that we can’t keep up economically, or simply repairing or recovering from the damage done.
The other feature of the past year has been the number of posts and articles I see where climate scientists are saying ‘ok, we didn’t really expect that…’
The Guardian reported on the weekend about what is happening in Antarctica,
In 18 March, 2022, scientists at the Concordia research station on the east Antarctic plateau documented a remarkable event. They recorded the largest jump in temperature ever measured at a meteorological centre on Earth. According to their instruments, the region that day experienced a rise of 38.5C above its seasonal average: a world record.
This startling leap – in the coldest place on the planet – left polar researchers struggling for words to describe it. “It is simply mind-boggling,” said Prof Michael Meredith, science leader at the British Antarctic Survey. “In sub-zero temperatures such a massive leap is tolerable but if we had a 40C rise in the UK now that would take temperatures for a spring day to over 50C – and that would be deadly for the population.”
This amazement was shared by glaciologist Prof Martin Siegert, of the University of Exeter. “No one in our community thought that anything like this could ever happen. It is extraordinary and a real concern,” he told the Observer. “We are now having to wrestle with something that is completely unprecedented.”
https://www.theguardian.com/environment/2024/apr/06/simply-mind-boggling-world-record-temperature-jump-in-antarctic-raises-fears-of-catastrophe
The article goes on to explain what that means now,
These events have raised fears that the Antarctic, once thought to be too cold to experience the early impacts of global warming, is now succumbing dramatically and rapidly to the swelling levels of greenhouse gases that humans continue to pump into the atmosphere.
These dangers were highlighted by a team of scientists, led by Will Hobbs of the University of Tasmania, in a paper that was published last week in the Journal of Climate. After examining 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 repercussions for both local Antarctic ecosystems and the global climate system.
“The extreme lows in Antarctic sea ice have led researchers to suggest that a regime shift is under way in the Southern Ocean, and we found multiple lines of evidence that support such a shift to a new sea ice state,” said Hobbs
What does this mean? Worst case scenario is if the whole of Antarctica melts we would have an average 60m sea level rise across the planet. In New Zealand that’s every coastal city and town needing to be relocated, plus airports, ports, and most of the main trunk line and much of State Highway 1 in the South Island.
Full pole melt isn’t going to happen in the human scale short or medium term. Data has historically been difficult to collect from Antarctica, but the current predictions from the IPCC seem woefully inadequate (.3 – 1.1m overall by the end of the century). Instead there is the suggestion of 5m as the Western ice sheets and glaciers melt completely. That’s based on what scientists know in 2024, not what is actually going to happen if shit keeps getting weirder year by year. But this is what people mean when they talk about runaway climate change. It’s the point where the unpredictable becomes common and causes more unpredictability and feeds back into itself. Precautionary principle applies again, we really don’t want to go there.
The melting of west Antarctica appears locked in even with rapid transition to low carbon. When I looked online I couldn’t find timelines for its collapse that took the evolving unpredictability into account and/or us doing what we are doing now which is failing to drop GHGs fast.
Five metres in New Zealand is significant for many places, including rail/roading/airport infrastructure. Invercargill, Dunedin, Napier, Wellington, Auckland airports are gone. Big chunks of Christchurch’s eastern suburbs and the northern coastal towns are underwater. South Dunedin. Whole suburbs in Wellington’s low lying land. So many areas of Auckland’s long sea edge.
You can have a play online to see how where you live will fare. Bear in mind not just your house, but transport routes, industry, supply lines.
It’s not just sea level rise, it’s storm surges, drought/flood cycles, cyclones and slips. Again, this is what is already locked in. What happens if we don’t lower GHGs fast is much worse.
Also in the Guardian piece is the problem of Antarctica warming causing mass algae death. Once the algae start dying, that’s not only the whole ocean food chain undercut (including our own sources of fish), but also the role algae plays in the carbon cycle. Short version: if enough algae die, global warming will increase faster. Algae are also critical in earth’s oxygen supply.
All of that is still able to be mitigated: we can limit the damage by dropping fossil fuel and other emissions fast, mass restoration of ecosystems including forests (not forestry), and shifting to regenerative not extractive/polluting economies. West Antarctica is locked in, but how fast that happens is still something we can affect.
The opportunity for mitigation doesn’t stay open indefinitely, there is a point when it becomes too late. Because of the way global physics works in time, what we do today impacts over coming decades. Waiting until the crisis is at the door is past the point we can do much about collapse. Climate collapse at that level is the end of civilisation as we know it.
Still thinking ‘she’ll be right’ in New Zealand? Go read up about wet bulb temperature.
All of which is to say two things. This is why adaptation without mitigation is an utter nonsense.
And, this is an actual emergency. Not in the future, but here and now. So why aren’t we acting as if it is?
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