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Pages 5-15

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From page 5...
... As increasing levels of atmospheric CO2 drive Earth toward a warmer climate state, an improved understanding of how climate dynamics could change is needed to inform public policy deci sions. Research on the climates of Earth's deep past can address several questions that have direct implications for human civilization: How high will atmospheric CO2 levels rise, and how long will these high levels persist?
From page 6...
... However, this more recent paleoclimate record captures only part of the known range of climate phenomena; the waxing and waning of ice sheets in a bipolar glaciated world under atmospheric CO2 levels at least 25 percent lower than current levels. In contrast to this reasonably well documented record of recent cli mate dynamics and at least partial understanding of the short-term feed backs that have operated in icehouse states of the recent past, the climate dynamics of past periods of global warming and major climate transitions are considerably less well understood.
From page 7...
... , large-scale floral and faunal ecosystem migration, and widespread extinctions in the deep ocean. A key requirement for an improved understanding of deep-time climate dynamics is the integration of high-resolution observational records across critical intervals of paleoclimate transition with more sophisticated modeling.
From page 8...
... . HIGH-PRIORITY DEEP-TIME CLIMATE RESEARCH AGENDA The committee, with substantial contributions from a broad cross section of the scientific community, has identified the following six ele ments of a deep-time scientific research agenda as having the highest priority to address enduring scientific issues and produce exciting and critically important results over the next decade: Improved Understanding of Climate Sensitivity and CO2-Climate Coupling Determining the sensitivity of the Earth's mean surface temperature to increased greenhouse gas levels in the atmosphere is a key requirement for estimating the likely magnitude and effects of future climate change.
From page 9...
... An improved understanding of these processes, which may drive further changes in surface temperatures in a future warmer world, is important in light of the substantial effects that higher temperatures would have on tropical ecosystems and ultimately on regional extratropical climates through teleconnections. Sea Level and Ice Sheet Stability in a Warm World Large uncertainties in the theoretical understanding of ice sheet dynamics currently hamper the ability to predict future ice sheet and sea level response to continued climate forcing.
From page 10...
... Understanding the Hydrology of a Hot World Studies of past climates and climate models strongly suggest that the greatest impact of continued CO2 forcing would be regional climate changes, with consequent modifications of the quantity and quality of water resources -- particularly in drought-prone regions -- and impacts on ecosystem dynamics. A fundamental component of research to understand hydrology under warmer conditions is the requirement -- because of its potential for large feedbacks to the climate system -- for an improved understanding of the global hydrological cycle over a full spectrum of CO2 levels and climate conditions.
From page 11...
... Modeling future biodiversity losses and biosphere-climate feedbacks, however, is inherently difficult because of the complex, nonlinear interactions with competing effects that result in an uncertain net response to climatic forcing. How rapidly biological and physical systems can adjust to abrupt climate change is a fundamental question accompanying present-day global warming.
From page 12...
... • Enhanced paleoclimate modeling with a focus on past warm worlds and extreme and/or abrupt climate events, including improved parameterization of conditions that are relevant to future climate, devel opment of higher-resolution modules to capture regional paleoclimate variability, and an emphasis on paleoclimate model intercomparison studies and "next-generation" paleoclimate data-model comparisons. An increase in model spatial resolution will be required to capture smallerscale features that are more comparable to the highly spatially resolved geological data that can be obtained through ocean and continental drill ing.
From page 13...
... Making the transition from singleresearcher or small-group research efforts to a much broader-based interdisciplinary collaboration will be possible only through a modification of scientific research culture, and will require substantially increased programmatic and financial support. EDUCATION AND OUTREACH STRATEGIES -- STEPS TOWARD A BROADER COMMUNITY UNDERSTANDING OF CLIMATES IN DEEP TIME Despite the potential of the deep-time geological record to provide unique insights into the global climate system's sensitivity, response, and ability to recover from perturbation, the public -- and indeed many scientists -- have minimal appreciation of the value of understanding deep-time climate history and appear largely unaware of the relevance of far distant times for Earth's future.
From page 14...
... Such concepts provide an opportunity to help disparate audiences understand that the Earth has archived its climate history and that this archive, while not fully understood, provides crucial lessons for improving our understanding of Earth's climate future. Such relatively simple but relevant messages provide a straightforward mechanism for an improved understanding in the broader community of the importance of paleoclimate studies.
From page 15...
... Also, it is uniquely the deep time record that has archived the full temporal range of climate change impacts on marine and terrestrial ecosystems, including ecological tipping points. An integrated research program -- a deep-time climate research agenda -- to provide a considerably improved understanding of the processes and characteristics over the full range of Earth's potential climate states offers great prom ise for informing individuals, communities, and public policy.


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