The hockey stick of doom is the graph of the stock of atmospheric carbon that governs the degree of planetary warming. The system of dynamic equations that govern the stock of atmospheric carbon, global temperatures, ice sheet cover, and sea levels describe the earth’s self-regulatory system since the origin of life on our planet — we just discovered them in the twentieth century. They are expected to work the same way on any planet with carbon, oxygen, water and organic life. What fossil modernity has done is dramatically accelerate the accumulation of carbon in the atmosphere, leading to anthropogenic climate forcing. Unless we can act collectively to not only cut down the rate of carbon emissions but to actually reduce the stock of atmospheric carbon, the global climate is going to get very, very harsh indeed: thermal burdens will make large parts of the global south virtually unlivable thereby triggering massive population pulses to the north; sea levels may rise quite dramatically, posing an unprecedented risk to coastal communities world wide; the climate will not only become warmer but dramatically more unstable, with much higher frequencies and amplitudes of extreme climate events like heat waves, droughts, flooding, hurricanes, snowstorms, and so on; our food supply will be at greater and greater risk as the century proceeds, in turn posing existential risks to human civilization at the planetary scale.
Technical solutions are already feasible and widely understood. What is required to get off the hockey stick of doom is a wholesale remaking of global energy systems, food production and land use patterns: transportation, housing and industry have to be electrified and made more energy efficient; clean energy from renewables and nuclear power plants has to replace dirty energy from coal, oil and gas; food production and land use have be transformed from carbon emitters into carbon sinks. Make no mistake — this is a considerable undertaking. The problem is that we don’t have an effective world government that can plan, fund and implement global decarbonization.