2061 can be achieved
Hurricane #1 Missouri, Sasha Buzzubov and Jessica Sucher
In our Science paper, Pacala and I envisioned a world where “policies … would inevitably be renegotiated periodically to take into account results of R&D, experience with specific wedges, and revised estimates of the size of the Stabilization Triangle.” In effect, we were anticipating the concept of iterative risk management, which works forward from the present instead of backward from the distant future, and which features learning as we go. Iterative risk management focuses on targets 10 and 20 years ahead, in addition to targets 50 years ahead. Target updating might occur as often as every 10 years, to incorporate new insights from Earth-system science and lessons learned from wedge deployment.
Right now, especially in international politics, discussion focuses on a poorly defined, multi-century concept, the ultimate rise of the average temperature of the Earth’s surface. There are heated arguments about whether that rise should be capped at 1.5 or 2.0 degrees Celsius (2.7 or 3.6 degrees Fahrenheit), relative to its pre-industrial value. By contrast, if diplomats were debating the implementation of iterative risk assessment, negotiations would become more hard-headed. Specifically, there would be more attention to decade-scale global emissions targets.
What specific value for the 50-year target would I recommend?
Today’s global emissions rate for carbon dioxide is 30 billion tons per year. For the world to emit in 2061 no more than 30 billion tons of carbon dioxide is as difficult a task as I could endorse today, taking into account the salience of other objectives to which I assign comparable importance, including preventing nuclear war, alleviating global poverty, and protecting the planet’s biodiversity.