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Uncertainty in Climate Change Research: An Integrated Approach. Chris E Forest The Pennsylvania State University ASP Summer Colloquium July 21 - August 6, 2014. Who am I ??. The “A-list†Mash-Up: A Physics & Math junky. A Professor of Climate Dynamics and Meteorology # PennState .
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Uncertainty in Climate Change Research: An Integrated Approach Chris E Forest The Pennsylvania State University ASP Summer Colloquium July 21 - August 6, 2014
Who am I ?? • The “A-list” Mash-Up: • A Physics & Math junky. • A Professor of Climate Dynamics and Meteorology #PennState. • A Co-PI on the Network for Sustainable Climate Risk Management (SCRiM). • A pragmatist & realist. • A biker-hiker-outdoor Dad. • Twttr: @ChrisEForest • Google+:ceforest67@gmail.com • LinkedIn:ceforest@psu.edu
What are my goals? • For this talk — A brief introduction to uncertainty language and some things we “know” about climate change • For this workshop — • To teach and be taughtby your cohort — your research, your interests, your backgrounds, your excitement of those that will lead the next generation • For my research — • To characterize and communicate the risks of climate change
What is this talk about? • Introducing the language of uncertainty • Introducing some “certainty” about climate change
Types of Uncertainty • Structural/Parametric • Aleatoric/Epistemic • Deterministic/Stochastic • Quantifiable/Non-quantifiable
Characterizing Model Uncertainty • Multi-Model Ensembles — MMEs • Perturbed Parameter/Physics Ensembles — PPEs • Initial Condition Ensembles
MIPs: Model Intercomparison Projects • GOAL: Assess Structural Uncertainty due to model structure & experimental design • The 1st: AMIP • Atmospheric Model Intercomparison Project • AGCM: Atmospheric General Circulation Models • The 2nd: CMIP • Coupled Model Intercomparison Projects • Atmosphere-Ocean GCMs [versions: 1/2/3/5/6] • Then many more: CCMIP, PMIP, CFMIP, …
What do we “know” about anthropogenic climate change? • Two key observations: • Greenhouse gases (GHGs) have increased since pre-industrial times (~1750CE) due to human activity. • Globally, surface temperatures have increased. • Plus, we have multiple observational records that are consistent with these changes.
2. Globally, surface temperatures have increased. “Each of the last 3 decades has been successively warmer than any preceding decade since 1850” • Globally averaged • Surface Temperature Anomaly • relative to 1961-1990 (ºC) • Years • (IPCC WG1 AR5 Figure SPM.1a)
IPCC AR5: Working Group 1 “Warming in the climate system is unequivocal” • (IPCC WG1 AR5 Figure SPM.1b)
Additional lines of evidence: Observed precipitation changes • (IPCC WG1 AR5 Figure SPM.2)
Additional lines of evidence: Observations of Snow Cover, Sea Ice Extent, Ocean Heat Content, & Sea Level Change • (IPCC WG1 AR5 Figure SPM.3)
What do we “know” about anthropogenic climate change? • Two key observations: • Greenhouse gases (GHGs) have increased since pre-industrial times (~1750CE) due to human activity. (e.g., Linda’s talk) • Globally, surface temperatures have increased. • Plus, we have multiple observational records that are consistent with these changes. • Fundamental science states that: • Changes in GHGs disrupt the planet’s energy balance. • The climate system responds by adjusting to this imbalance (albeit not uniformly). • This basic premise is encoded in Climate Models.
Are the models predicting the past? Yes. Land and Ocean Temperatures and Sea Ice Area • Sea Ice • Ocean Heat Content • IPCC AR5 WG1: Figure SPM.6