Exploring Societal Risk
Even experts tend to skirt the issue of how much uncertainty remains. When the Intergovernmental Panel on Climate Change (IPCC) discussed the expected "climate sensitivity" of the atmosphere to a doubling of CO2 at approximately 3o C, it does not emphasize the substantial uncertainty around that estimate (some estimates range to well over 6o C. Similarly, there are many discussions about sea levels being most likely to rise by somewhere between 1 and 2 feet by 2100, even though some experts are anticipating more than 10 feet of sea level rise by 2100.
Since Risk = Probability x Consequence, focusing on the most likely climate outcome is misleading when it comes to understanding the nature of climate risk. This is one reason that a risk-neutral Social Cost of Carbon may be as low as $35/ton, while a risk-averse Social Cost of Carbon could be higher than $1,000/ton.
This chapter of Your Climate Change PhD explores the topic of risk, and how it relates to understanding the future of climate change, including:
- The known knowns, known unknowns, and unknown unknowns of climate change
- The relationship of climate uncertainties to risk
- The growing uncertainty associated with climate change impacts and outcomes as climate-relevant probability distributions change
- Exceedance curves as a measure of risk
- Examples of risk-based climate assesslments
In each case you’ll gain insight into the covered topics, and be hyperlinked to curated knowledge collections in the Climate Web.