Uncertainty terminology : Version 1.0

2020

Bulletin of the American Meteorological Society, 2016

What: Approximately 70 participants from 30 countries on all five continents met to discuss the need, approaches, and challenges in uncertainty quantification in climate modeling and projection. More details, including workshop presentations, can be found online (http://indico.ictp.it/event/a14268/) When: 13

Bulletin of the American Meteorological Society, 2011

How to understand and reason about uncertainty in climate science is a topic that is receiving increasing attention in both the scientific and philosophical literature. This paper provides a perspective on exploring ways to understand, assess and reason about uncertainty in climate science, including application to the Intergovernmental Panel on Climate Change (IPCC) assessment reports. Uncertainty associated with climate science and the science-policy interface presents unique challenges owing to complexity of the climate system itself, the potential for adverse socioeconomic impacts of climate change, and politicization of proposed policies to reduce societal vulnerability to climate change. The challenges to handling uncertainty at the science-policy interface are framed using the 'monster' metaphor, whereby attempts to tame the monster are described. An uncertainty lexicon is provided that describes the natures and levels of uncertainty and ways of representing and reasoning about uncertainty. Uncertainty of climate models is interpreted in the context of model inadequacy, uncertainty in model parameter values, and initial condition uncertainty. We examine the challenges of building confidence in climate models and in particular, the issue of confidence in simulations of the 21 st century climate. The treatment of uncertainty in the IPCC assessment reports is examined, including the IPCC 4 th Assessment Report conclusion regarding the attribution of climate change in the latter half of the 20 th century. Ideas for monster taming strategies are discussed for institutions, individual scientists, and communities.

There are different kinds of uncertainty. I outline some of the various ways that uncertainty enters science, focusing on uncertainty in climate science and weather prediction. I then show how we cope with some of these sources of error through sophisticated modelling techniques. I show how we maintain confidence in the face of error.

2010

This Working Paper reviews the main reasons why definite and conclusive evidence in the field of climate change is almost an impossibility. It analyses the main elements that explain natural climatic change and reflects on the high level of uncertainty in the system, which in many ways is inherent to the system itself, and presents the latest evidence. The following section presents in a stylised fashion the key features of uncertainty and how it relates to climate change. Then, an analysis of how GHG have been measured is followed by a discussion of the different GHG, natural and human-induced events that have a significant bearing on climate change. The Working Paper concludes with an overview of past, present and future climate change and with a summary of the main ideas discussed throughout the text.

Climatic Change, 2011

This paper argues that the IPCC has oversimplified the issue of uncertainty in its Assessment Reports, which can lead to misleading overconfidence. A concerted effort by the IPCC is needed to identify better ways of framing the climate change problem, explore and characterize uncertainty, reason about uncertainty in the context of evidence-based logical hierarchies, and eliminate bias from the consensus building process itself.

Regional Environmental Change

Significance, 2013

The global aerosol problem First, some background. Atmospheric aerosol particles are tiny solid or liquid particles suspended in air. Their diameters can range from a nanometer to 100 micrometers-about the diameter of human hair; a cubic centimetre of air can contain hundreds of them or millions. They can be made of carbon from fires and combustion, sea salt, mineral dust, organic matter, sulphate or many other things. They can travel a long way: orange particles from Africa can sometimes be seen on car windscreens in Britain. Aerosol particles can affect the climate in many ways. They can do it directly, by reflecting or absorbing solar radiation. As bright dusts travels across dark ocean it reflects more sunlight back into space and therefore cools the ocean surface. Black carbon deposited on bright ice or snow has the opposite effect: it absorbs heat and warms the surface below. Uncertainties in climate models Living with uncertainty in an uncertain world Climate change is hugely complicated, physically and statistically. Debate rages about predictions and the uncertainties within them. Understanding such uncertainties is vital. Lindsay Lee works on the Leeds University GLOMAP model of aerosols in the atmosphere and the changes they may bring. This article was a runner-up in the Significance/Young Statisticians Section writers' competition earlier this year.

Climatic Change, 2014

In public debate surrounding climate change, scientific uncertainty is often cited in connection with arguments against mitigative action. This article examines the role of uncertainty about future climate change in determining the likely success or failure of mitigative action. We show by Monte Carlo simulation that greater uncertainty translates into a greater likelihood that mitigation efforts will fail to limit global warming to a target (e.g., 2 • C). The effect of uncertainty can be reduced by limiting greenhouse gas emissions. Taken together with the fact that greater uncertainty also increases the potential damages arising from unabated emissions , any appeal to uncertainty implies a stronger, rather than weaker, need to cut greenhouse gas emissions than in the absence of uncertainty.

2005

Please note that Tyndall working papers are "work in progress". Whilst they are commented on by Tyndall researchers, they have not been subject to a full peer review. The accuracy of this work and the conclusions reached are the responsibility of the author(s) alone and not the Tyndall Centre.