A tipping point in climate science is defined as a “critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system”.
The climate scientist Timothy Lenton and colleagues argue that potential tipping points in systems such as the Greenland ice sheet, the Amazon rainforest, the Atlantic Gulf Stream system and Arctic sea ice are globally interconnected. Shifts in one can accelerate changes in the others. This may happen much sooner than previously expected, given the current pace of global warming.
As we become more aware of the everyday effects of global warming, terms such as tipping point are more widely used. This summer’s heatwaves, droughts and forest fires in the global North are driving an urgent convergence between scientific and popular understanding.
Attribution science uses agreed methods and vast data banks to quantify how much more likely tipping points are given the rate of warming compared to a baseline. “My personal feeling about attribution science,” says Radley Horton of Columbia University, “is that it’s less a revolution in our understanding, and more a revolution in how we apply knowledge to attribute blame and apportion responsibility, and perhaps most importantly, to inform and motivate communities and stakeholders to take action.”
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This makes it easier for media and citizens to link climate change to disasters and to understand that abstract processes such as global warming actually consist of events, some of which may represent tipping points of qualitative change.
This Irish Government negotiations this week on agricultural carbon emissions brought home the understanding that human activity – via fossil fuel consumption and carbon emissions – is responsible for warming and that if it is not curbed and reversed, such catastrophic tipping points are made more likely.
Humans must respect the natural world of which they are a component part, rather than consider themselves promethean outsiders
The death on Wednesday of the climate scientist James Lovelock, creator of the Gaia hypothesis in the 1960s, reminds us how far understanding has changed since then. In his 2006 book, The Revenge of Gaia, he ruefully welcomed a statement made by four representative climate science organisations in 2001 justifying his work that had been so disputed: “The Earth System behaves as a single, self-regulating system comprised of physical, chemical, biological and human components.”
Humans must respect the natural world of which they are a component part, rather than consider themselves promethean outsiders entitled to abuse and shape it as they will. That course risks destroying their role in the earth’s system, which can adapt to survive our destruction.
Reductionist
Lovelock’s approach is still criticised as reductionist by those who say it underestimates the human capacity to understand and therefore change behaviours that cause global warming. A central feature of human society is the potential for awareness of the contradictions between natural cycles and human behaviour, more specifically the pursuit of limitless growth for profit of industrial capitalism, which treats nature as a cost-free externality.
This sort of consciousness demands a willingness to change, but how is that to be organised? Does it depend on individual action related to market forces and choices, or on collective action mobilising communities to force governments’ hands?
From this social science perspective, a tipping point is better defined as a critical point in an evolving situation that leads to a new and irreversible development, but which people don’t see happening. In a much-cited discussion, the political scientist Colin Hay counterpoises tipping points like these to crises in which there is a collective political awareness of and perception of the relevant contradictions, plus an ability to address them. Hay is impatient with imprecise definitions of both. His discussion is surely relevant here.
The great challenge facing humanity on the climate crisis is how to tackle it collectively by recognising that limitless capitalist and consumer growth, mainly among the richest people in the global North, is incompatible with human survival. That would turn the crisis to advantage by curtailing carbon emissions within a very short timescale, since tipping points will happen otherwise and anyway.
Two alternatives are possible in Hay’s analytical schema: catastrophic equilibrium and failure. The first recalls the indecisive and unresolved situation described by the Italian Marxist Antonio Gramsci as one in which “the old is dying yet the new cannot be born; in this interregnum a great variety of morbid symptoms appear”. Arguably, that is where humanity is heading now.
Failure would allow Lovelock’s Gaia take its course.