Ticking towards climate midnight: we may have breached six of nine planetary boundaries. And the leaked IPCC report will stiffen your spine
Whenever we somewhat flag at A/UK, and wonder why we keep so many plates spinning around a new politics and ideas of power, legitimate reports on the climate crises are sure to stiffen our spines.
So many dots have to be joined, at many levels and at the same time, if we are to avoid possibly catastrophic outcomes. The nearness of our biosphere to meltdown and runaway extremes is news we need to keep hearing - to maintain our activities on many fronts.
Two reports in the last week came to us with this kind of news. The mighty Katherine Trebeck tweeted a link to an interview with climate systems guru Will Steffen (full text here). Here’s a few headlines and supporting texts:
Six of the nine planetary boundaries may have been transgressed:
We set the boundary [for “a safe operating space for humanity’] at an atmospheric CO2 concentration of 350 ppm. Both observations and model simulations show that such a boundary would cap temperature rise at much less than 1°C, and the Earth System would remain stable at that level.
We set the zone of uncertainty at 350–450 ppm CO2. The idea is that the risks of climate impacts and of triggering a trajectory of the Earth System away from Holocene conditions increases as the CO2 concentration rises.
Observations bear this out. At over 410 ppm, we are already experiencing increases in the frequency and severity of several damaging extreme weather events – extreme heat, drought, intense rainfall, wildfires, tropical cyclones.
In addition, several tipping points in the Earth System that could drive it towards hotter conditions, even without any further human forcing, are becoming active.
These include loss of Arctic sea ice, melting of Greenland and West Antarctic ice sheets, drought and fires in the Amazon forest, melting of Siberian permafrost, and slowdown of the Atlantic Ocean circulation.
In general, most of the control variables for the boundaries are moving away from the safe operating space, or, if they were within, are moving closer to the boundary itself.
An exception to this trend is atmospheric ozone depletion, where the banning of CFCs had led to a stabilization of ozone levels with a good prospect of increasing ozone concentration over the southern hemisphere polar regions over the coming decades.
For all of the other boundaries, however, the control variable is moving in the wrong direction. When the next major update of the PB framework is published, hopefully later in 2021, it is likely that at least six of the nine boundaries will be transgressed.
Hothouse Earth
The ultimate question is when could the Earth System be pushed onto an irreversible trajectory towards a much hotter state – Hothouse Earth – and how close are we to pushing it onto that trajectory.
We suggest that Paris climate targets may be insufficient to prevent a Hothouse Earth pathway. This analysis implies that, even if the Paris Accord target of a 1.5°C to 2.0°C rise in temperature is met, we cannot exclude the risk that a cascade of feedbacks could push the Earth System irreversibly into a ‘Hothouse Earth pathway.
The challenge that humanity faces is to create a “Stabilized Earth” pathway that steers the Earth System away from its current trajectory toward the threshold beyond which is Hothouse Earth. The human created Stabilized Earth pathway leads to a basin of attraction that is not likely to exist in the Earth System’s stability landscape without human stewardship to create and maintain it.
Creating such a pathway and basin of attraction requires a fundamental change in the role of humans on the planet.
…So where is the Anthropocene going? Can we quickly change the trajectory of the Earth System away from its current pathway towards Hothouse Earth and onto a Stabilized Earth pathway? There is no clear answer to that question, but perhaps the various attempts to answer it can be grouped into two very broad, contrasting approaches.
One is that technology is the solution – switching to renewable energy systems, smart grids, electricified transport systems, high-tech agriculture and so on – will create a sustainable future. Economies can grow and we can become wealthier, but decoupling will reduce our imprint on the Earth System.
The other broad pathway is that we require a much deeper transformation, one that is based on a fundamental shift in core values – degrowth, less consumptive lifestyles, from ‘wealth’ to ‘well-being’, living much simpler but more satisfying lives, reconnecting with the biosphere, and so on.
As of yet, there is no clear answer to these questions, and opinions and debates continue. Probably the only sure thing we can say about the future is that it hasn’t happened yet.
Also last week, Agence-France Presse got hold of a draft from a forthcoming IPCC report (the UN’s climate body) which made the stakes of Professor Steffen’s ‘pathways’ as high as they could be.
From the article:
Climate change will fundamentally reshape life on Earth in the coming decades, even if humans can tame planet-warming greenhouse gas emissions, according to a landmark draft report from the UN's climate science advisors obtained by AFP.
Species extinction, more widespread disease, unliveable heat, ecosystem collapse, cities menaced by rising seas -- these and other devastating climate impacts are accelerating and bound to become painfully obvious before a child born today turns 30.
The choices societies make now will determine whether our species thrives or simply survives as the 21st century unfolds, the Intergovernmental Panel on Climate Change (IPCC) says in a draft report seen exclusively by AFP.
But dangerous thresholds are closer than once thought, and dire consequences stemming from decades of unbridled carbon pollution are unavoidable in the short term. "The worst is yet to come, affecting our children's and grandchildren's lives much more than our own," the report says.
By far the most comprehensive catalogue ever assembled of how climate change is upending our world, the report reads like a 4,000-page indictment of humanity's stewardship of the planet.
But the document, designed to influence critical policy decisions, is not scheduled for release until February 2022 -- too late for crunch UN summits this year on climate, biodiversity and food systems, some scientists say.
The draft report comes at a time of global "eco-awakening" and serves as a reality check against a slew of ill-defined net-zero promises by governments and corporations worldwide. The challenges it highlights are systemic, woven into the very fabric of daily life.
They are also deeply unfair: those least responsible for global warming will suffer disproportionately, the report makes clear. And it shows that even as we spew record amounts of greenhouse gases into the atmosphere, we are undermining the capacity of forests and oceans to absorb them, turning our greatest natural allies in the fight against warming into enemies.
It warns that previous major climate shocks dramatically altered the environment and wiped out most species, raising the question of whether humanity is sowing the seeds of its own demise.
"Life on Earth can recover from a drastic climate shift by evolving into new species and creating new ecosystems," it says.
There are at least four main takeaways in the draft report, which has gone through a major revision and is unlikely to change before its release.
The first is that with 1.1 degrees Celsius of warming clocked so far, the climate is already changing. A decade ago, scientists believed that limiting global warming to two degrees Celsius above mid-19th century levels would be enough to safeguard our future.
That goal is enshrined in the 2015 Paris Agreement, adopted by nearly 200 nations who vowed to collectively cap warming at "well below" two degrees Celsius -- and 1.5 degrees if possible. On current trends, we're heading for three degrees Celsius at best.
Earlier models predicted we were not likely to see Earth-altering climate change before 2100. But the UN draft report says that prolonged warming even beyond 1.5 degrees Celsius could produce "progressively serious, centuries' long and, in some cases, irreversible consequences".
Last month, the World Meteorological Organization projected a 40 percent chance that Earth will cross the 1.5-degree threshold for at least one year by 2026. For some plants and animals, it could be too late. "Even at 1.5 degrees Celsius of warming, conditions will change beyond many organisms' ability to adapt," the report notes.
Coral reefs -- ecosystems on which half a billion people depend -- are one example. Indigenous populations in the Arctic face cultural extinction as the environment upon which their livelihoods and history are built melts beneath their snow shoes.
A warming world has also increased the length of fire seasons, doubled potential burnable areas, and contributed to food systems losses.
Secondly, the world must face up to this reality and prepare for the onslaught - this is a major takeaway of the report. "Current levels of adaptation will be inadequate to respond to future climate risks," it cautions. Mid-century projections -- even under an optimistic scenario of two degrees Celsius of warming -- make this an understatement.
Tens of millions more people are likely to face chronic hunger by 2050, and 130 million more could experience extreme poverty within a decade if inequality is allowed to deepen.
In 2050, coastal cities on the "frontline" of the climate crisis will see hundreds of millions of people at risk from floods and increasingly frequent storm surges made more deadly by rising seas. Some 350 million more people living in urban areas will be exposed to water scarcity from severe droughts at 1.5 degrees Celsius of warming -- 410 million at two degrees Celsius.
That extra half-a-degree will also mean 420 million more people exposed to extreme and potentially lethal heatwaves. "Adaptation costs for Africa are projected to increase by tens of billions of dollars per year with warming greater than two degrees," the report cautions.
Thirdly, the report outlines the danger of compound and cascading impacts, along with point-of-no-return thresholds in the climate system known as tipping points, which scientists have barely begun to measure and understand.
A dozen temperature trip wires have now been identified in the climate system for irreversible and potentially catastrophic change. Recent research has shown that warming of two degrees Celsius could push the melting of ice sheets atop Greenland and the West Antarctic -- with enough frozen water to lift oceans 13 metres (43 feet) -- past a point of no return.
Other tipping points could see the Amazon basin morph from tropical forest to savannah, and billions of tonnes of carbon leech from Siberia's permafrost, fuelling further warming.
In the more immediate future, some regions -- eastern Brazil, Southeast Asia, the Mediterranean, central China -- and coastlines almost everywhere could be battered by multiple climate calamities at once: drought, heatwaves, cyclones, wildfires, flooding.
But global warming impacts are also amplified by all the other ways that humanity has shattered Earth's equilibrium. These include "losses of habitat and resilience, over-exploitation, water extraction, pollution, invasive non-native species and dispersal of pests and diseases," the report says.
There is no easy solution to such a tangle of problems, said Nicholas Stern, former chief economist at the World Bank and author of the landmark Stern Review on the Economics of Climate Change. "The world is confronting a complex set of interwoven challenges," said Stern, who did not contribute to the IPCC report. “Unless you tackle them together, you are not going to do very well on any of them."
There is very little good news in the report, but the IPCC stresses that much can be done to avoid worst-case scenarios and prepare for impacts that can no longer be averted, the final and fourth takeaway.
Conservation and restoration of so-called blue carbon ecosystems -- kelp and mangrove forests, for example -- enhance carbon stocks and protect against storm surges, as well as providing wildlife habitats, coastal livelihoods and food security.
Transitioning to more plant-based diets could also reduce food-related emissions as much as 70 percent by 2050. But simply swapping a gas guzzler for a Tesla or planting billions of trees to offset business-as-usual isn't going to cut it, the report warns.
"We need transformational change operating on processes and behaviours at all levels: individual, communities, business, institutions and governments," it says. "We must redefine our way of life and consumption."
More from AFP, and a follow-up report from Yahoo! News. The IPCC themselves have commented on reports on this draft here.