A flurry of reports released each year around the COP summit, update us on the state of global climate action and climate change. I have – like many – become somewhat desensitised to their grim contents. But two recent reports, when read side-by-side, shook me deeply.
The first, the UN Emissions Gap Report, tracks the gap between where global emissions are heading with current country commitments and where they ought to be to limit warming to 1.5 degrees. Its subtitle hits like a tonne of bricks: “Broken Record – Temperatures hit new highs, yet world fails to cut emissions (again)”. Greenhouse gas emissions rose to an all-time high in 2022 and the concentration of carbon dioxide in the atmosphere is higher than at any point in at least 3 million years – maybe much longer – meaning 2023 will be the warmest year on record, probably by a large margin.
As commitments currently stand, greenhouse gas emissions are set to rise by 2030, instead of entering the steep decline necessary to limit the worst effects of climate change. If countries fully implement their current commitments to cut emissions, the world is on track to heat by between 2.5 and 2.9 degrees, it concludes.
The second report, State of the Cryosphere 2023, makes clear just how catastrophic this heating would be. Like the UN Gap report, its subtitle pulls no punches: “Two Degrees Is Too High; we cannot negotiate with the melting point of ice”. Even breaching 1.5 degrees, which is likely to happen in the coming decade, will cause profound and (to an extent) irreversible changes to the planet’s ice.
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The cryosphere – Earth’s frozen water in ice sheets, sea ice, permafrost, polar oceans, glaciers and snow – is at ground zero for climate change.
Accepting 2 degrees of warming as the new constant would commit the world to “between 12 and 20 metres” of sea level rise. This would compel a large share of the world’s population that live near coastlines to abandon their homes.
It would also make summers in the Arctic Ocean ice-free nearly every year, amplifying and reinforcing climate change. Without ice, polar seas are darker and absorb more heat. Removing the sea ice that buttresses ice sheets will speed up melt and sea-level rise. Sea ice is also a critical ecosystem, which will be altered “beyond recognition” in a heated world.
A warmer Arctic will also thaw permafrost that currently traps vast amounts of greenhouse gases. At 2 degrees of warming, “annual total permafrost emissions would probably total the size of the entire European Union’s emissions from 2019″. Even warming of 1.5 degrees is too high to prevent extensive emissions from thawing permafrost.
Warming is also leading to “corrosive ocean acidification” as the oceans absorb much of the excess carbon dioxide. Keystone marine species like krill “may not survive” in these acidified waters, with cascading impacts on the food chain.
A large share of the global population relies on mountain glaciers and snowpack for drinking water and irrigation. Warming will cause many of these glaciers to melt and disappear, severely affecting people and ecosystems and potentially making downstream areas uninhabitable. Glaciers in the Swiss Alps lost 10 per cent of their ice in the past two years because of heatwaves, which are expected to intensify as time goes on. Millions of people are also at risk from flooding from glacial lake outbursts.
These unimaginably destructive dynamics will play out over decades and centuries, depending on our efforts to cut greenhouse gas emissions, but the report also warns that impacts, from permafrost thaw to sea level rise, could be abrupt, leaving little time to prepare and adapt.
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The findings of this report are not wild speculation, unfortunately, but are based on extensive scientific literature and observations. The foreward, written by the president of Chile and prime minster of Iceland, concludes that “we have time, but not much time” and that we need “systemic change” to rapidly cut emissions.
It is accepted by most experts that breaching 1.5 degrees is inevitable, but the message of the cryosphere scientists is that “this insanity cannot and must not continue” and that Cop28 must be where the course is corrected. The greater the temperature rise, the greater the damage to people and nature, and the more difficult it will be to bring back to safe levels.
It is distressing to track this enormous and growing gap between where we need to go, and where we are going and to witness the catastrophic consequences. We don’t need any technological breakthroughs and can take action immediately to slow and reverse global warming – and these measures can bring many benefits, for energy security, health and nature – but change is too little and too late.
It is too easy to become desensitised to this bad news, but if we collectively continue to ignore it, we will become the proverbial frogs in a boiling pot, unable to jump out.
Hannah Daly is professor of sustainable energy at University College Cork