Decision making under climate uncertainty: Part I by Judith Curry
It's such a pleasure to read such intelligent writing, such a change from the usual alarmist trash.
Decision making under climate uncertainty: Part I
The question needs to be asked as to whether the early articulation of a preferred policy option by the UNFCCC has stimulated a positive feedback loop between politics, science, and science funding that has accelerated the science (and its assessment by the IPCC) towards the policy option (CO2 stabilization) that was codified by the UNFCCC.
This feedback loop marginalizes research on natural climate variability (forced and unforced) on regional and global scales, focuses research on model development rather than observations (particularly paleoclimate), and values model agreement over a full exploration of model uncertainty (including model structure).
The net result of such a feedback loop is an overconfident assessment of the importance of greenhouse gases in future climate change. Which has brought us to our current position between a rock and a hard place, where we lack the kinds of information that we need to understand climate change more broadly and develop and evaluate a broad range of policy options.
This is the point I've made many time to those who keep harping on with "it's better to do something, just in case"
Under conditions of deep uncertainty, optimal decisions based upon a consensus can carry a considerable risk. Obersteiner et al. describes the uncertainty surrounding the climate change science is a two-edged sword that cuts both ways: what is considered to be a serious problem could turn out to be less of a threat, whereas unanticipated and unforeseen surprises could be catastrophic.
Obersteiner et al. argues that the strategy of assuming that climate models can predict the future of climate change accurately enough to choose a clear strategic direction might be at best marginally helpful and at worst downright dangerous: underestimating uncertainty can lead to strategies that do not defend the world against unexpected and sometimes even catastrophic threats. Obersteiner et al. notes that another danger lies on the other side of the sword if uncertainties are too large and analytic planning processes are abandoned.
Obersteiner et al. argues that stabilization of greenhouse gas concentrations at a target level is a non-robust strategy in an environment that is extremely uncertain and most likely nonlinear. The UNFCCC strategy has dominated the framing of IPCC assessment by focusing their efforts on the documentation of dangerous climate change in the context of specific levels of warming associated varying amounts of atmospheric carbon dioxide. Embellishing the IPCC’s climate paradigm has come to dominate national and international climate programs and their funding.
The current decision making framework based on the UNFCCC/IPCC has led to a situation where we are between a rock and hard place in terms of decision making. The strategy (primarily model based) has provided some increased understanding and a scenario with about 3C sensitivity that is unlikely to budge much with the current modeling framework. A great deal of uncertainty exists, and emissions target policies based on such uncertain model simulations are not robust policies.
It seems that we have reached the point of diminishing returns for the science/decision making strategy reflected by the UNFCCC/IPCC. Its time to consider some new decision making frameworks and new scientific ideas. In Part II, we will explore some robust decision making strategies that consider Weitzman’s “fat tails” and ponder the kinds of scientific information needed to support such strategies.
A quite academic writing style, which will put many off, but for me, very refreshing