Understanding Earth's Deep Past Lessons for Our Climate Future (2011) / Chapter Skim
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5 Implementing a Deep-Time Climate Research Agenda
5 Implementing a Deep-Time Climate Research Agenda
Pages 106-137
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From page 106... ...
This chapter presents a scientific research agenda designed both to answer the series of major questions posed in Chapter 1 regarding the impact of the projected rise in atmospheric pCO2 and to provide a more refined understanding of the important processes -- uniquely present in the deep-time geological record -- that will drive the Earth system as it transitions to a warmer world. The chapter also describes the research tools and community effort that will be required to implement this research agenda and provides recommendations for an education and outreach strategy designed to broaden scientific and general community understanding of the contribution that can be derived only from the deep-time record.
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From page 107... ...
Data using new and existing proxies could then be synthesized to develop an authoritative global temperature and atmospheric pCO2 history -- at various resolutions -- for the full span of Earth's history. Improved constraints on levels of radiative forcing and equilibrium climate sensitivity are needed for past warm periods and major climate transitions.
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From page 108... ...
Moreover, the fundamental mismatch between climate model outputs, modern observations, and paleoclimate proxy records discussed in Chapter 2 highlight the degree to which science's current understanding of how tropical and higher-latitude temperatures respond to increased CO2 forcing remains limited. An improved understanding of these processes, which may drive significant changes in surface temperatures in a future warmer world, is imperative given the potential dire effects of higher temperatures on tropical ecosystems and the domino effect of polar warming on ice sheet stability, the stability of permafrost (which carries a large load of green house gases)
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From page 109... ...
Moreover, studies of past warm periods indicate that equilibrium sea level in response to current warming may be substantially higher than model projections indicate due to the influence of dynamic processes that have not been operative in the recent past. Efforts to address these issues will have to focus on past periods of ice sheet collapse that accompanied transitions from icehouse to greenhouse conditions, to provide context and understanding of the "worst-case" forecasts for the future.
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From page 110... ...
Proxy improvement efforts should include strategies for better constraining the paleogeographic setting of proxy records, including latitude and altitude or bathymetry. Understanding Tipping Points and Abrupt Transitions to a Warmer World Studies of past climates and climate models show that Earth's climate system does not respond linearly to gradual CO2 forcing, but rather
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From page 111... ...
cli mate transitions in the geological record -- including past hyperthermals -- should be the focus of future fully integrated paleoclimate, paleoecologic, and modeling collaborations. Key insights to be gleaned from such studies include an improved understanding of how various components of the climate system responded to such abrupt transitions, in particular during times when the rates of change were sufficiently large to imperil biotic diversity.
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From page 112... ...
The deep-time record of past biotic turnovers and mass extinction events associated with warm periods (many associated with massive outgassing of CO2 or methane) , transient warmings, and major transi tions between climate states offers an undertapped repository from which unique insights can be obtained regarding patterns of ecosystem stress, the potential for ecological collapse, and mechanisms of ecosys tem recovery.
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From page 113... ...
The issue of how Arctic ecosystems will respond if sea ice disappears permanently and/or the Greenland ice sheet retreats significantly can only be addressed through studies of past warm periods, such as the mid to late Cretaceous and the early Cenozoic, when the Arctic was ice-free and supported lush temperate rainforests and associated fauna. As with the other elements of a deep-time research agenda, improved dynamic models, more spatially and temporally resolved paleoclimate and paleontological datasets with high precision and chronological constraint, and data-model comparisons, are all critical components of future research efforts to better understand ecosystem processes and the dynamic interactions with changing climates.
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From page 114... ...
This will maximize the potential for paleoclimate modeling studies to inform climate model development in general and for future climate simulations.
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From page 115... ...
For mineral-based paleobarometers and continental paleotemperature proxies, calibration studies are needed in modern soil systems over a spectrum of landscapes and climate regimes in order (1) to better understand the influence of local climate, regional and soil hydrology, and soil productivity on soil CO2 contents, temperature, and moisture -- the input parameters for proxy transfer functions and pCO2 calculations, and (2)
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From page 116... ...
Continued development of interactive analytical data bases that permit the integration of new proxy data about past climate parameters and boundary conditions, within an existing rock-based spa tial and temporal framework, is critical to facilitate the integration and comparison of multiple proxy time series along latitudinal-longitudinal
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From page 117... ...
This proposed deep-time paleoclimate drilling would substantially expand the scope of the existing International Continental Drilling Program and provide a complementary perspective to the oceanic focus of IODP, targeting a much broader and longer swath of Earth history, as well as providing an additional emphasis on the critical -- but understudied -- paralic zone that holds considerable potential for delineating marine-terrestrial linkages. Secondly, the proposed deep-time continental drilling program would provide a platform from which to develop multiproxy records with the requisite spatial and temporal resolution and unprecedented continuity and preservation.
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From page 118... ...
The proposed expanded continental and ocean drilling would provide three fundamental elements of the scientific research agenda presented earlier in this chapter: • Temporal Continuity and Improved Temporal Resolution: The continuity of drill cores -- and the proxy time series developed from them -- provide superb records, particularly when compared with outcrop-based studies where accessibility has traditionally been limited by erosion and burial, as well as by exposure-related mineralogical and chemical alteration. The continuity and preservational quality of drill cores would maxi mize the potential for deep-time climate proxy records that are chronostratigraphically resolved at the orbital to seasonal range throughout the geological record.
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From page 119... ...
Notably, coring was the only way to recover a complete section of the basin because of the extremely discontinuous outcrop in the often urbanized and heavily vegetated region. Key to the success of the project was an offset drilling strategy consist ing of a transect of seven 1- to 1.5-km boreholes that took advantage of the tilted strata within the half-graben Newark Basin, with each borehole sampling a different part of the section and with about 25% stratigraphic overlap between stratigraphically adjacent boreholes.
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From page 120... ...
120 UNDERSTANDING EARTH'S DEEP PAST BOX 5.1 Continued FIGURE 5.1 Drilling in the Newark Basin, New Jersey, using an offset drilling method. SOURCE: Photo and text courtesy of Paul Olsen, Lamont-Doherty Geo logical Observatory of Columbia University.
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From page 121... ...
121 IMPLEMENTING A DEEP-TIME CLIMATE RESEARCH AGENDA FIGURE 5.2 Color wavelet power spectrums for Neogene and Trias sic lacustrine sediments of the Newark Basin showing a full range of precession-related (~20, ~100, 405 kyr) orbital cycles (Olsen and Kent, 1996, 1999)
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From page 122... ...
122 UNDERSTANDING EARTH'S DEEP PAST BOX 5.2 Paleo-Rainforest Reconstruction Through Continental Drilling The Denver Basin project (1997-2008) was an endeavor by the Denver Museum of Nature and Science to study the geology and paleontology of Late Cretaceous and Paleogene strata along the eastern flank of the Colora do Front Range.
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From page 123... ...
An enhanced effort to model past warm intervals and periods of abrupt climate change across thresholds and possible tip ping points is needed to produce models of future climate that can be adjusted to scenarios that include forcings or feedbacks not revealed by nearer-time paleoclimate reconstructions.
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From page 124... ...
This limitation is actually magnified for paleoclimate models, where following the lead of modern climate models can be hampered by lack of geographically extensive datasets and/or uncertain boundary conditions. In spite of these limitations, it is critical to run paleoclimate simulations at higher spatial resolutions both to capture high-resolution details required by sparser observational data and to maintain the ability for paleoclimate modeling conclusions to inform and evaluate future cli mate change simulations.
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From page 125... ...
Model-model-data comparisons, in particular for past warm climates characterized by elevated CO2, provide a means of assessing not only the range of possible climate changes but also the credibility of climate model parameterizations in a way that future climate experiments are incapable of doing. Recent advances in the capability of models to predict the spatial and temporal distribution of key environmental variables (temperature, precipitation and runoff, marine biological productivity, deep-water oxygen status)
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From page 126... ...
Technical support is also required to reconfigure low-resolution climate models to run more efficiently on massively parallel computer architectures. • Establishment of paleoclimate modeling archives that are better integrated with paleoclimate data archives, or better populating the growing IPCC-related archives (e.g., the Paleoclimate Modeling Intercomparison Project [PMIP]
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From page 127... ...
Strategies for Fostering Focused Deep-Time Scientific Interaction While the paleoclimate characteristics of past warm worlds and times of major climate transitions contained in the deep-time geological record constitute a substantially underdeveloped archive offering considerable potential for major scientific discoveries, such discoveries are unlikely to be made through single-PI disciplinary research or small-scale collaborative projects. For the full potential of the deep-time paleoclimate archive to be realized, it is critical to foster broad-based collaborations of observation-based scientists and climate modelers.
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From page 128... ...
Importantly, no such archive yet exists that can integrate with or accommodate paleo climate modeling archives -- a fundamental necessity for the proposed synergistic and interdisciplinary research approach to deep-time paleo climatology. Macrostratigraphy is a novel web-based data-sharing program (Figure 5.4)
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From page 129... ...
129 IMPLEMENTING A DEEP-TIME CLIMATE RESEARCH AGENDA Solid Earth Rock Record Living Fluid Earth Earth Sh an a .P n E et er sa nd Bri dg et D iem FIGURE 5.4 Logo for the macrostratigraphy database, Macrostrat. See http://macrostrat.geology.wisc.edu and http://strata.geology.wisc.edu/ mibasin.
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From page 130... ...
Such institutes could easily be designed to incorporate sec ondary school teachers, museum specialists, and science journalists (see discussion in "Education and Outreach -- Steps Toward a Broader Community Understanding of Climates in Deep Time" below)
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From page 131... ...
The public discussion regarding climate change and global warming is complex and fractious, in part reflecting the lack of adequate scientific literacy among the general public, an active campaign of antiscience disinformation, and insufficient efforts on the part of the scientific community to disseminate complex information in an effective manner. Similar things could be said about the public understanding of geological time, the age of the Earth, radioisotopic dating, and how scientists determine the age of events in Earth history.
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From page 132... ...
Irrespective of these challenges, however, extinct animals and plants, ancient worlds, and natural disasters do resonate with people, and these elements all present good starting points for broader discussions about past climates Audience-Specific Strategies and Examples K-12 For elementary and secondary audiences, it is important to be aware of age-specific learning styles and state educational standards. Children are interested in dinosaurs and living animals, and these provide wonderful opportunities to discuss extinction and ecosystems.
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From page 133... ...
In addition, a number of NSF-funded projects have generated web-based education tools. One such program that deals specifically with GCMs is the Educational Global Climate Modeling Program,4 a collaboration between Columbia University and NASA's Goddard Institute for Space Studies, which allows web visitors to download and run simple climate models.
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From page 134... ...
The deep-time observation and modeling communities both need to break into the popular science realm by emphasizing their more compel ling and understandable elements. Great opportunities exist for the popu larization of ice cap and ocean drilling, both of which occur in dramatic settings that are unfamiliar and interesting to the general public.
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From page 135... ...
; enhanced presence on the radio (e.g., a paleoclimate feature on National Public Radio's (NPR's) Science Friday, Terry Gross interviews of proxy data analysts and modelers, Talk radio)
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From page 136... ...
This paleoclimate record contains facts that are startling to most people -- there have been times when the poles were forested rather than being icebound; there were times when the polar seas were warm; there were times when tropical forests grew at midlatitudes; more of Earth history has been greenhouse than icehouse. Such relatively simple but relevant messages provide a straightforward mechanism for an improved understanding in the broader community of the importance of paleoclimate studies.
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From page 137... ...
show that with an appropriately funded focal point for scientific interaction -- a characteristic of each of these programs -- it is possible to effectively convey rather complex scientific issues and sci entific accomplishments to a broader audience. This reinforces the call for programmatic and funding support for broad-based interdisciplinary collaborations for deep-time paleoclimate science advanced in this report, because these collaborative focal points could easily include the type of dedicated E&O resources as the successful models noted above.
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