Emergency Arctic cooling and subsequent planetary restoration
John Nissen
2024-07-23
To Dawn Bonfield, MBE, FREng
From John Nissen, chair of the Planetary Restoration Action Group (PRAG)
Emergency Arctic cooling and subsequent planetary restoration
Dear Dawn,
I am chair of the Planetary Restoration Action Group (PRAG): a group of scientists, engineers and climate activists who have the mission of planetary restoration and have a plan to advocate which involves taking an engineering approach to climate change. I heard you being interviewed by Jim Al-Khalili on The Life Scientific (BBC Radio 4) and realised that you might have a special interest in planetary restoration, especially as regards achieving long-term sustainability goals. The ultimate aim is to restore the world to a healthier state for the benefit of the young people of today; indeed one could consider such restoration as their unalienable human right. But, prior to such restoration, it is necessary to counter the forces which could lead to catastrophic climate change and catastrophic sea level rise.
I learnt that you are a great champion for engineering, which tends to be the underdog to science in our education and the public perception of value. Thus the public and politicians are in awe of climate scientists, who have focussed on emissions reduction as a “solution” to climate change while cooling intervention (also known as SRM for “Solar Radiation Management”) gets barely a mention in reports such as the AR6 summary for policy-makers [1] although it has the potential to cool the planet, reverse climate change and slow the currently accelerating sea level rise.
The obvious approach of an engineer in seeking a solution to the current situation is to look at the forces at play and particularly the positive feedbacks which are causing acceleration in climate change and sea level rise. Our group is particularly focussed on the Arctic, where there are a number of processes which are having accelerated effects, including:
- rapid Arctic warming contributing to a sharp increase in the Earth’s Energy Imbalance;
- the disruption of jet stream behaviour such as to accelerate the growth in weather extremes;
- the melt of the Greenland Ice Sheet accelerating sea level rise;
- the release of the potent greenhouse gas, methane, from thawing permafrost;
- the decline in strength of the Atlantic Meridional Overturning Circulation (AMOC).
Our conclusion is that the Arctic needs to be refrozen back to the condition it was before any of these accelerated effects could be detected, which was around 1980.
By these arguments, refreezing the Arctic becomes the top priority for climate action! But the forces to be overcome to refreeze the Arctic have not been adequately assessed by the climate community: for example, the IPCC does not officially acknowledge that tipping processes have been activated in the Arctic – the Paris COP agreement was to prevent tipping process activation by keeping the global temperature below 1.5C which it already is!
At present the Arctic is in unmitigated meltdown. The basic requirement is to cool the Arctic faster than it is warming in order to halt this meltdown and then reverse it. The largest factor in Arctic warming is probably albedo loss. Since 1980, the cooling power of the Arctic sea ice alone has declined by 25% through albedo loss [2]. If one accounts for snow retreat as well, the total heating from albedo loss could amount to as much as 1.0 W/m2 averaged globally, which is equivalent to 0.5 petawatt of heating power focussed in the Arctic.
But then there is growing heat flux arriving in the Arctic as result of the incursion of Atlantic and Pacific water, extra warm as the result of global warming. We estimate that this could already be adding as much as another 0.5 petawatt of heating power focussed in the Arctic. Cooling intervention might have to provide a colossal 1.0 petawatt of cooling power directed into the Arctic to overcome the heating from both albedo loss and warm water incursion. Note that 1.0 petawatt of heating would equal the global heating from CO2 but be focussed in the Arctic.
We have looked at various techniques for refreezing the Arctic. There is only one which might provide enough cooling power and that is Stratospheric Aerosol Injection (SAI). Research suggests that subpolar-focussed SAI over a number of years could suffice to lower the Arctic temperature without significant adverse side-effects [3]. It is based on modelling.
But, on the precautionary principle, one should not rely on the models which may not take account of all the sources of Arctic heating and their magnitude. And we should not rely on SAI being scalable to any value: there are going to be practical limitations. Our engineering assessment is that the Arctic meltdown could be very close to a point of no return where SAI would be unable to stop it. Catastrophic climate change and sea level rise would become inevitable. We have a climate emergency warranting immediate preparations for deployment of SAI at scale.
This is sobering news. On the other hand we note that SAI has the ability to cool the whole planet back to its 1980 level which would save many ecosystems from collapse and restore biodiversity. By promoting life in soils and the oceans, and suppressing emissions of potent greenhouse gases like methane, it should be possible to reduce the warming effect of greenhouse gases in the atmosphere and simultaneously improve food productivity. Together with SAI, the planet could be returned to a healthy, productive and sustainable state within 3-5 decades. We believe this is not just a powerful incentive, but a human right for the young people of today.
We are trying to form a group of eminent scientists and engineers who could argue our case for refreezing the Arctic using the emergency deployment of SAI as the top priority for climate change action. Would you consider joining them?
Best regards,
John Nissen on behalf of PRAG
Bath, UK
Mobile: 07890 657 498
[2] Duspayev, Flanner and Riihela (GRL, 17th July)
Earth's sea ice radiative effect from 1980 to 2023
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109608
[3] Hayes et al. (2023)
A subpolar-focussed stratospheric aerosol injections deployment scenario
https://iopscience.iop.org/article/10.1088/2515-7620/ac8cd3
dawnbo...@btinternet.com
Many thanks John for getting in touch and a really interesting email. I am definitely not a climate scientist but recognise, of course, that we are approaching tipping points and that action must be taken to stop this. I will look more closely at what you are proposing, but think that I would be unlikely to join your campaign as I still have an intrinsic fear of us doing such drastic ‘human-made’ things to the planet (and yes, I know we are already doing them) which are untested. But clearly we are reaching a point where we are being left with no choice. For now, I will keep a watching brief on your suggestion, and endeavour to find out more. But I thank you for your email and for the explanation.
Best wishes
Dawn
Dawn Bonfield MBE FREng CEng FIMMM FICE HonFIStructE FWES HonDEng
Professor of Practice, Engineering for Sustainable Development, King’s College London
President, Commonwealth Engineers’ Council (2023-2025)
Royal Academy of Engineering Visiting Professor, Aston University
Director, Towards Vision
Past President, Women’s Engineering Society
Tel: 07881905520 | 01438 820850
Twitter: @dawnbonfield
Working towards a vision of diversity and inclusion in engineering.