Existential climate-related security risk: A scenario approach

https://www.breakthroughonline.org.au/papers


Existential climate-related security risk: A scenario approach
 
Foreword by Admiral Chris Barrie, AC RAN Retired
 
“In 2017-18, the Australian Senate inquired into the implications of climate change for Australia’s national security. The Inquiry found that climate change is “a current and existential national security risk”, one that threatens the premature extinction of Earth-originating intelligent life or the permanent and drastic destruction of its potential for desirable future development”….  [this study paints] a disturbing picture of the real possibility that human life on earth may be on the way to extinction, in the most horrible way.  In Australia recently we have seen and heard signals about the growing realisation of the seriousness of our plight.”  (Admiral Chris Barrie, AC RAN Retired, is Honorary Professor, Strategic & Defence Studies Centre, Coral Bell School of Asia Pacific Affairs, Australian National University, Canberra. He is a member of the Global Military Advisory Council on Climate Change and was Chief of the Australian Defence Force from 1998 to 2002.)
 
With the commitments by nations to the 2015 Paris Agreement , the current path of warming is 3°C or more by 2100. But this figure does not include “long-term” carbon-cycle feedbacks, which are materially relevant now and in the near future due to the unprecedented rate at which human activity is perturbing the climate system. Taking these into account, the Paris path would lead to around 5°C of warming by 2100.7 Scientists warn that warming of 4°C is incompatible with an organised global community, is devastating to the majority of ecosystems, and has a high probability of not being stable.
 
A 2050 SCENARIO
 
2020–2030: Policy-makers fail to act on evidence that the current Paris Agreement path ­ in which global human-caused greenhouse emissions do not peak until 2030 ­ will lock in at least 3°C of warming. The case for a global, climate-emergency mobilisation of labour and resources to build a zero-emission economy and carbon drawdown in order to have a realistic chance of keeping warming well below 2°C is politely ignored. As projected by Xu and Ramanathan, by 2030 carbon dioxide levels have reached 437 parts per million ­ which is unprecedented in the last 20 million years ­ and warming reaches 1.6°C.18
 
2030–2050: Emissions peak in 2030, and start to fall consistent with an 80 percent reduction in fossil-fuel energy intensity by 2100 compared to 2010 energy intensity. This leads to warming of 2.4°C by 2050, consistent with the Xu and Ramanathan “baseline-fast” scenario.19 However, another 0.6°C of warming occurs ­ taking the total to 3°C by 2050 ­ due to the activation of a number of carbon-cycle feedbacks and higher levels of ice albedo and cloud feedbacks than current models assume.  [It should be noted that this is far from an extreme scenario: the low-probability, high-impact warming (five percent probability) can exceed 3.5–4°C by 2050 in the Xu and Ramanathan scheme.]
 
2050: By 2050, there is broad scientific acceptance that system tipping-points for the West Antarctic Ice Sheet and a sea-ice-free Arctic summer were passed well before 1.5°C of warming, for the Greenland Ice Sheet well before 2°C, and for widespread permafrost loss and large-scale Amazon drought and dieback by 2.5°C. The “hothouse Earth” scenario has been realised, and Earth is headed for another degree or more of warming, especially since human greenhouse emissions are still significant.  While sea levels have risen 0.5 metres by 2050, the increase may be 2–3 metres by 2100, and it is understood from historical analogues that seas may eventually rise by more than 25 metres. Thirty-five percent of the global land area, and 55 percent of the global population, are subject to more than 20 days a year of lethal heat conditions, beyond the threshold of human survivability.  The destabilisation of the Jet Stream has very significantly affected the intensity and geographical distribution of the Asian and West African monsoons and, together with the further slowing of the Gulf Stream, is impinging on life support systems in Europe.  North America suffers from devastating weather extremes including wildfires, heatwaves, drought and inundation. The summer monsoons in China have failed, and water flows into the great rivers of Asia are
severely reduced by the loss of more than one-third of the Himalayan ice sheet. Glacial loss reaches 70 percent in the Andes, and rainfall in Mexico and central America falls by half. Semi-permanent El Nino conditions prevail.  Aridification emerges over more than 30 percent of the world’s land surface. Desertification is severe in southern Africa, the southern Mediterranean, west Asia, the Middle East, inland Australia and across the south-western United States.
 
Impacts: A number of ecosystems collapse, including coral reef systems, the Amazon rainforest and in the Arctic. Some poorer nations and regions, which lack capacity to provide artificially-cooled environments for their populations, become unviable. Deadly heat conditions persist for more than 100 days per year in West Africa, tropical South America, the Middle East and South-East Asia, which together with land degradation21 and rising sea levels contributes to perhaps a billion people being displaced.  Water availability decreases sharply in the most affected regions at lower latitudes (dry tropics and subtropics), affecting about two billion people worldwide. Agriculture becomes nonviable in the dry subtropics.
 
Most regions in the world see a significant drop in food production and increasing numbers of extreme weather events, including heat waves, floods and storms. Food production is inadequate to feed the global population and food prices skyrocket, as a consequence of a one-fifth decline in crop yields, a decline in the nutrition content of food crops, a catastrophic decline in insect populations,
desertification, monsoon failure and chronic water shortages, and conditions too hot for human habitation in significant food-growing regions.
 
The lower reaches of the agriculturally-important river deltas such as the Mekong, Ganges and Nile are inundated, and significant sectors of some of the world’s most populous cities ­ including Chennai, Mumbai, Jakarta, Guangzhou, Tianjin, Hong Kong, Ho Chi Minh City, Shanghai, Lagos, Bangkok and Manila ­ are abandoned. Some small islands become uninhabitable. Ten percent of Bangladesh is inundated, displacing 15 million people. According to the Global Challenges Foundation’s Global Catastrophic Risks 2018 report, even for 2°C of warming, more than a billion people may need to be relocated due to sea-level rise, and In high-end scenarios “the scale of destruction is beyond our capacity to model, with a high likelihood of human civilisation coming to an end”.
 
National security consequences: For pragmatic reasons associated with providing only a sketch of this scenario, we take the conclusion of the Age of Consequences ‘Severe’ 3°C scenario developed by a group of senior US national-security figures in 2007 as appropriate for our scenario too: Massive nonlinear events in the global environment give rise to massive nonlinear societal
events . In this scenario, nations around the world will be overwhelmed by the scale of change and pernicious challenges, such as pandemic disease.  The internal cohesion of nations will be under great stress, including in the United States, both as a result of a dramatic rise in migration and changes in agricultural patterns and water availability. The flooding of coastal communities around the world, especially in the Netherlands, the United States, South Asia, and China, has the potential to challenge regional and even national identities . Armed conflict between nations over resources,
such as the Nile and its tributaries, is likely and nuclear war is possible. The social consequences range from increased religious fervor to outright chaos . In this scenario, climate change provokes a
permanent shift in the relationship of humankind to nature ’.
 
Excerpted from “Existential climate-related security risk: A scenario approach”, by David Spratt and Ian Dunlop, Breakthrough- National Centre for Climate Restoration, Melbourne, Australia, May 2019, online at https://www.preventionweb.net/publications/view/65812 .  Ian Dunlop is a member of the Club of Rome,.  Formerly an international oil, gas and coal industry executive, chairman of the Australian Coal Association, chief director of the Australian Institute of Company Directors, and chair of the Australian Greenhouse Office Expert Group on Emissions Trading 1998-2000.