What's The Arctic Death Spiral?
- The ice in the Arctic is a huge mirror reflecting the sun's heat back into space;
- Through global warming we've melted this ice and shrunk the mirror;
- Less sunlight is reflected, causing more warming and further ice-melt, in a vicious circle of positive feedback;
- Even after we stop CO₂ emissions and even if human population reduces, temperatures will continue to rise;
- We're heading for global crop failures and monumental sea-level rises;
- The only way to stop irreversible, devastating climate change is to stop releasing CO₂ and make the planet colder using geo-engineering;
- Every day we delay, that colossal task becomes even bigger.
The ice that used to cover the Arctic Ocean is spiralling down towards zero:
This chart records volume not area. Measuring just area misses a crucial dimension: the ice is getting progressively thinner (see On Thin Arctic Sea Ice), and so melts more quickly each summer. Arctic Sea-Ice Area Loss charts the parallel reduction in area.
The downward trend in Arctic sea-ice extent began around 1950. Reliable figures for sea-ice volume start in 1979. It's plotted on rectangular axes below.
What's The Problem?
The IPCC is almost certainly wrong with its claim in October 2018 that
the likelihood of an Arctic Ocean free of sea ice in summer would be once per century with global warming of 1.5°C, compared with at least once per decade with 2°C
Despite the noise, the best-fit line on this chart of real data looks inexorable and suggests that Septembers with no Arctic sea ice could first appear from 2030 and will become a permanent feature around 2045, with the ice-free periods then extending to last multiple months:
Remember: the ice is melting because the Earth has got warmer. Even if we stop releasing CO₂ into the atmosphere and temperatures stabilise, the ice will continue to melt.
Maybe the IPCC know something the real data doesn't and this line is going to flatten out or curve up before hitting zero. Or maybe the current climate-change models don't work in the Arctic? They don't even match the recorded data for recent years!
Does This Matter?
As Arctic sea ice disappears, the following positive feedback effects have already started and help explain why the Arctic is warming at more than twice the global average rate:
- less sunlight is reflected: the Arctic warms faster
- reflective snow and ice are lost faster and further across on the neighbouring land, allowing permafrost to defrost
- methane locked in the Arctic seabed and neighbouring tundra for thousands of years is escaping; just a small fraction of the estimated deposits would cause 0.5°C of extra warming; there's a low probability of a larger release leading to a rise of 6-8°C - see An Arctic Methane Digest
- more permafrost thaws; more organic matter is available for bacteria to digest; their accelerated digestion makes extra heat, further melting the permafrost; this releases additional methane and CO₂
- warmer Arctic summers are drying the boreal forests; they more often burn; soot spreads across the neighbouring Arctic snow and sea ice; less sunlight is reflected; the area gets temporarily hotter; sea ice and permafrost thaw faster; in addition, more CO₂ is lost from biomass
- more open ocean means bigger waves, slowing and reducing the formation of the next year's ice
- the sea channels out of the Arctic spend less of the year blocked by ice, allowing more ice to drift away
- removing Arctic ice weakens a key driver for ocean currents (cold, salty water sinking in the Arctic) and slows the rate at which dissolved CO₂ and atmospheric heat is pulled into the deep ocean
- slower ocean currents amplify their own feedback: the surface waters become warmer and a) absorb less CO₂; b) become less dense and even slower to sink, further reducing the force driving the overturning currents; c) less dissolved CO₂ and oxygen means the ocean supports less biomass than it otherwise would, further reducing the absorption of atmospheric CO₂
- these feedbacks get accelerated by the Latent-Heat Tipping Point
Even if we stop further greenhouse gas emissions right now and stabilise atmospheric CO₂ at current levels: these feedbacks mean Arctic sea ice will continue to retreat and the global climate will continue to warm.
Our governments and economic modellers base their non-action on misinformation. The world's only Nobel-laureate climate economist, William Nordhaus, states:
There is virtually no chance that the rise in temperature will be less than the target 2°C even with immediate, universal, and ambitious climate change policies.
He suggests we deal with climate change by applying a carbon tax but admits:
If the damage function shows higher costs, or has sharp curvature at or around 2°C ... then the revised optimal policy would have much higher abatement costs
Nordhaus's damage function is based on the IPCC's wrong predictions and furthermore does not include the Arctic feedbacks. The real damage function will have both higher costs and sharp curvature.
What Are The Consequences?
The temperature history of the Earth shows our planet has two stable equilibria: an ice-covered ball reflecting most sunlight; and ice-free periods much hotter than today. For the past million years or so we've enjoyed an unstable equilibrium somewhere in the middle, cycling through ice ages and warm periods. It looks like we're about to upset that equilibrium and force the planet into a warm phase never before encountered by our species.
Here is a plot of CO₂ levels over the last 800,000 years, showing how we've overshot off the top of the scale:
The consequences of this include:
- Our agriculturally productive land area is going to shrink, risking large-scale starvation - see Are We All Going To Die?
- We don't know how fast and how much methane will escape from the Arctic seabed - if the answer is "fast" we should expect a global failure in harvests leading to an end to our civilisation - see An Arctic Methane Digest.
- The Greenland ice sheet is 3km thick; it's melting at a rate of 300km3 per year; when it's gone, sea levels will rise 7m; this will take centuries but is inexorable - see How Fast Is Greenland Melting?
- The Antarctic ice sheet (the result of 400,000 years of snowfall) is melting at a rate of 150km3 per year; when it's gone... sea levels will rise a further 60m.
- These melt rates will only get faster, friction with the underlying land will reduce and vast chunks of ice sheet will slide into the sea.
It doesn't matter whether climate change is man-made or not: unless we refreeze the Arctic by making the world colder, these things will happen. If we continue with business as usual, they will accelerate.
Note: the Arctic sea ice is floating, so as it melts the sea level doesn't change.
- UK greenhouse gas emissions have fallen by 42% since 1990 - See The UK's True Carbon Emissions.
- The plane was going anyway, so my flying was energy-neutral - Your extra weight on the plane requires extra energy to be consumed in keeping you up. Airlines respond to demand by flying more planes - See Carbon-Neutral Flying.
What Should We Do?
- Why are we still subsidising fossil fuels?! - governments pay $500bn a year to support fossil fuels; the UK government paid $16bn a year in 2017-19
- A global carbon tax, which is gradually increased
- Stop burning fossil fuels asap
- (Grudgingly) accept that, until we have more renewable energy, we need nuclear power
- A massive research effort to invent cost-effective methods to become carbon-negative ie remove CO₂ from the atmosphere
- Devise and implement global-scale geo-engineering to reduce temperatures eg cloud-seeding, reflect vast amounts of sunlight, plant more trees - eg see Geo-engineering Using Terrestrial Mirrors, Geo-engineering Using Mirrors In Space and Geo-engineering By Reforesting
The biggest beneficiaries of the greenhouse gases released so far have the greatest moral obligation to act first to reverse the consequences. See Who Burnt All The Carbon?
When the Industrial Revolution started, the amount of carbon sitting in coal under Britain was roughly the same as the amount sitting in oil under Saudi Arabia.
What Should I Do?
- Reduce your carbon footprint (you know! stop flying, eat less beef, eat more vegetarian and vegan, blah, blah, blah) - see eg Food and Climate Change
- Tell your friends
- Lobby elected representatives to recognise the problem and start doing something about it: eg ask your MP to sign The Climate and Ecological Emergency Bill - see https://www.ceebill.uk/bill
- Maybe consider having fewer children than you'd ideally wish for
However, individual actions aren't going to help much. We need governments to radically change policy. So please:
- Join others eg Extinction Rebellion and Insulate Britain in non-violent direct action - this is a last resort: all other approaches have failed
If you're concerned about accusations of hypocrisy, don't be: the current system locks us into fossil-fuel use for pretty much all everyday activities.
Credits and References
- I thought I knew about climate change; on reading Peter Wadham's "A Farewell to Ice" I discovered I didn't - https://www.penguin.co.uk/books/273/273799/a-farewell-to-ice/9780241009437.html - other climate scientists suggest that some of the positive-feedback maths is wrong eg https://climatetippingpoints.info/2019/04/02/fact-check-will-an-ice-free-arctic-trigger-a-climate-catastrophe/
- The "Arctic Death Spiral" chart was created by Andy Lee Robinson
- "Summary for Policymakers of IPCC Special Report on Global Warming of 1.5°C approved by governments" - https://www.ipcc.ch/2018/10/08/summary-for-policymakers-of-ipcc-special-report-on-global-warming-of-1-5c-approved-by-governments/
- "PIOMAS Arctic Sea Ice Volume Reanalysis" - http://psc.apl.washington.edu/research/projects/arctic-sea-ice-volume-anomaly/
- "Arctic sea ice in transformation: A review of recent observed changes and impacts on biology and human activity" - https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013RG000431
- "Current rates and mechanisms of subsea permafrost degradation in the East Siberian Arctic Shelf" - https://www.nature.com/articles/ncomms15872
- "Projections and Uncertainties about Climate Change in an Era of Minimal Climate Policies" William Nordhaus - https://www.aeaweb.org/articles?id=10.1257/pol.20170046
- "NASA Carbon Dioxide" - https://climate.nasa.gov/vital-signs/carbon-dioxide/
- "Global Warming Natural Cycle" - http://ossfoundation.us/projects/environment/global-warming/natural-cycle
- NASA Ice Sheets page - https://climate.nasa.gov/vital-signs/ice-sheets/
- "Increased ice losses from Antarctica detected by CryoSat-2" - https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GL060111
- "Sustainable Energy - Without the Hot Air" by David MacKay - https://www.withouthotair.com/
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