Investigating the Interactions of the Atmosphere, the Broader Earth System, and Human Society

Research in SERE on coupled human and natural systems concentrates on the ecological and societal impacts of climate change and severe weather. SERE also conducts research that seeks to provide better understanding of the interactions among long-term climate change, climate variability, and weather extremes while reducing societal vulnerability to their impacts. Current research spans all aspects of the strategic priority.  We have chosen to highlight the interactions between the natural environment and human societies, focusing on impacts in the oceans, regional climate, extreme weather events, and economic sectors.

Impacts of Ocean Acidification on Coral Reefs  [HIGHLIGHT]

North American Regional Climate Change Assessment

Changes in Society-Relevant Extremes

IPCC Scientific Contributions

Overall US Sector Sensitivity Assessment

Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers

	Comparison of the major processes that need to be considered in modeling the carbonate systems in (A) a shallow benthis system (<100 m depth) and (B) an open ocean system (up to 6,000 m in depth). These are oversimpified representations. For example, the dissolution component in both systems involves complicated processes that include differences in mineralogies, organic matter respiration, etc. (compiled by J. Kleypas, 2006).

This project includes the organization and completion of a workshop held in April 2005, followed by a report that summarizes existing knowledge about ocean acidification and its impacts on marine calcifiers. Oceanic uptake of atmospheric carbon dioxide has predictable effects on ocean carbonate chemistry. Oceanic uptake of carbon dioxide lowers the pH of the ocean and consequently lowers the saturation states of carbonate minerals, which are used to form supporting skeletal structures in many major groups of marine organisms, as well as coral reefs.

The workshop, held in St. Petersburg, Florida, was designed to take the next step toward understanding the response of marine calcification to increasing atmospheric carbon dioxide concentration. Although workshop participants were drawn from a wide range of scientific disciplines, there was a clear convergence on the major scientific issues that should be pursued over the next five to ten years. Ten major areas for future research were identified and agreed upon at the workshop. Some of the research objectives require technological development, but others can be addressed immediately.

The report is intended as a guide to program managers and researchers to assist in designing projects that address these important questions. For example, the experts who contributed to the report present options for future research designs that take advantage of natural temporal and spatial variations, as well as existing observing systems. The report also provides guidance on efficiently coordinating research and monitoring (prioritizing needs, recommending partnerships, and capitalizing on existing efforts). It has generated wide interest across many groups. Government senators and representatives requested more information following the release of this report, as well as requested briefings to congressmen in Washington, DC. The lead author has received numerous requests for more information from the media, educators, museums, higher institutions of learning, nongovernmental organizations, and students of all ages.

Future research along these lines will cut across several groups at NCAR and the larger scientific community. Basic field work to conduct carbonate system monitoring on coral reefs was begun two years ago and will continue in coordination with NOAA's Coral Reef Monitoring Network. The topic of ocean acidification will continue as a component of the TIIMES biocomplexity-based research, and also overlaps with the NCAR Opportunity Fund project: Connecting Communities: Climate & Ecosystem Impact Research (CCCEIR), which focuses on linking NCAR's modeling tools such as the Community Climate System Model (CCSM) with marine ecosystem and food web models. Future work on how ocean acidification will affect marine communities will also naturally draw from ongoing ocean carbon cycle modeling efforts in CGD. The major goal of the collective research on ocean acidification at NCAR, through both specific research and coordination of others' efforts, is to better understand how calcifying marine organisms will respond to continued decreases in ocean pH, both at the organism and ecosystem levels. The main sponsors of the workshop and this research are the National Science Foundation, the National Oceanic and Atmospheric Administration (NOAA), and the US Geological Survey.

Kleypas, J.A., R.A. Feely, V.J. Fabry, C. Langdon, C.L. Sabine, and L.L. Robbins, 2006: Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers: A Guide for Future Research. Report of a workshop held 18-20 April 2006, St. Petersburg, FL, sponsored by NSF, NOAA, and the USGS. 88 pp. (Note: this report is available here in PDF format. Warning: large file, 10MB)

North American Regional Climate Change Assessment

	The base computational domain for NARCCAP Experiment 0. High-resolution climate simulations performed on this region will be analyzed to to study the effects of model size and boundary locations. Color indicates land height in this figure.

The North American Regional Climate Change Assessment (NARCCAP) is an international program that includes principal investigators from Canada and the UK. It aims to produce multiple high-resolution climate change scenarios for most of North America. This program will provide output to the climate analysis community for in-depth regional analyses of climate change. These analyses will benefit current research by the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4), among others. A total of four different coupled atmosphere-ocean global climate models (AOGCMs) will be used to provide boundary conditions for six different regional climate models, which will be run at 50km resolution for current conditions, as well as for the middle of the twenty-first century, based on the IPCC's SRES (Special Report on Emissions Scenarios) A2 (A2 refers to one of four scenario "families" of possible future emissions being explored by AR4 researchers.) High-resolution (50km) atmosphere-only global climate model runs will also be produced in this project to explore the uncertainties in future projects and scenarios based on different AOGCMs combined with different regional climate models.

This research project was initiated for the most part during FY2006. A multi-agency grant (NSF, NOAA, and the DOE) was obtained for the three-year-long project. Regional climate model runs have already been completed using the National Centers for Environmental Protection (NCEP) boundary conditions for 1980-2000. Analyses of these runs have begun, and preliminary results indicate that the six RCMs (regional climate models) accurately reproduce the observed climate for these years. Also, plans have been fashioned to convene a NARCCAP Users' Meeting in FY2007, to include climatologists interested in analyzing NARCCAP results in detail, climate impact researchers who wish to use the climate change scenarios, and regional climate modelers who will use the 50km RCM runs to provide initial and boundary conditions for running higher-resolution (e.g., 5km) simulations over smaller domains (i.e., sub-regions of North America).

During FY2007 analyses of the NCEP-driven runs will be completed, and a number of current and future climate simulations will be completed. Climate change scenarios will be produced from these runs and made available to climate change impacts researchers on a server at NCAR. Analyses of the future climate projects will also be developed. This project also contributes to research across other NCAR laboratories, with the involvement of Don Middleton (SCD) and Steve Sain (IMAGe). This research is supported by the National Science Foundation, NOAA, and the US Department of Energy.

Changes in Society-Relevant Extremes

	Glaciers, ice sheets and arctic ecosystems will be severely affected by climate change. Glaciers around the world are already shrinking, threatening wildlife and freshwater supplies. Global climate models predict extreme warming in the arctic if greenhouse gas emissions continue to rise. (Photo and text courtesy of David Suzuki)

Climate change has the potential to influence climate extremes, not only in quantity, but also in intensity and variability. This can lead to an increase in the occurrence of climate extremes, such as heat waves, heavy rainfall, and prolonged droughts. Extreme events are the main cause of damage to ecological and social systems. Global climate models (GCMs) have progressed enough in sophistication during the past few years to be able to provide useful information about these kinds of changes, as well as to provide data about possible changes in mean quantities of extreme events.

ISSE scientist Claudia Tebaldi, Jerry Meehl and Julie Arblaster (both of CGD), and Katherine Hayoe (Texas Tech, Lubbock) have analyzed and synthesized projected changes in a suite of temperature and precipitation indices, as simulated by various GCMs, that are contributing to the ongoing international Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment (AR4) activities. Significant changes in temperature extremes, consistent with a warming climate, are projected for most of the world's land masses, and the changes exhibit a very coherent pattern in these GCMs. Changes in precipitation are less stable across the different models, in terms of fine regional structures, but all of the models point to an intensification in precipitation amounts, especially for the high latitudes of the Northern Hemisphere and the tropics. Also associated with higher precipitation intensity, long periods of dry days emerge in the GCM pattern of climate extremes. The models show these dry spells occurring most frequently in the extratropical regions and mid-latitudes.

During FY2007, the researchers will continue comparing model simulations of extremes to observed trends in order to validate the model projections. Specifically, they will work on analyzing the dependence of the extremes behavior on ENSO or other climate indices (NAO, PNA and so on). This research is supported by the National Science Foundation.

These four images of the world show projections from 9 GCMs indicating possible future changes in extreme events (change is shown for the end of the 21st century compared to the end of the 20th century, under a mid-level emission scenario, A1B). Frost days (upper left) are the number of days when minimum temperature falls below freezing (0°C). The models predict fewer such days in the future everywhere, as the warm colors of the figure indicate, with relevant implications for agriculture and ecosystems. Precipitation intensity (upper right) is the average amount falling on a rainy day and is predicted to increase almost everywhere. Heat waves will become more severe (lower left), and consecutive dry days (lower right) are predicted to increase in number, on average during the year, in most regions at low/mid latitudes, with possibly challenging consequences for water availability and, when coupled with higher precipitation intensity, flood risk.

IPCC (Intergovernmental Panel on Climate Change) Fourth Assessment Report (AR4)

The IPCC was established by the WMO (World Meteorological Organization) and UNEP (UN Environment Programme) during the 1990s to assess scientific, technical and socioeconomic information relevant for the understanding of climate change, its potential impacts, and options for adaptation and mitigation. It is open to all Members of the UN and of the WMO. Three assessments have been released, the latest one in 2001. The Fourth Assessment Report (AR4) is due to be completed in mid-2007.

	This graphic from the Third Assessment Report shows both anticipatory and reactive methods that natural and human systems employ when adapting to climate change. Courtesy of the IPCC presentations and graphics page from www.ipcc.ch

SERE scientists were recruited during FY2006 to contribute to the IPCC's AR4. The AR4 consists of three Working Groups. These Working Groups (WGs) will assess material from different disciplines and will cover a diversity of approaches to uncertainty, reflecting differences in the underlying literature. WG I focuses on the natural sciences, WG III on the social sciences, and WG II covers both. One researcher in SERE is the Coordinating Lead Author of the chapter on "Industry, Settlement and Society," and as member of the team in charge of the WGs II and III on "Cross-cutting Themes of Adaptation, Mitigation, and Sustainable Development." Another SERE researcher is a Lead Author in WG II, "New Assessment Methodologies and the Characterization of Future Conditions," and Lead Author in WG I, "Regional Climate Projections." Several other SERE Lab scientists are contributing to the assessment in various important roles, from lead authorship to review editors.

The IPCC agreed that the AR4 will be completed in 2007, that the Working Group reports would be sequenced such that the Working Group I report would be finalized during the first quarter of 2007, Working Group II and Working Group III reports in mid-2007, and that the AR4 Synthesis Report would be finalized during the last quarter of 2007. Therefore, SERE researchers will continue to be involved with this project throughout FY2007.

This research contributes to several of the NCAR Strategic Goals. Several of the NCAR Laboratories have Coordinating Lead Authors as well as Lead Authors contributing to the AR4. SERE's involvement is funded by the National Science Foundation.

Overall United States Sector Sensitivity Assessment

It has been widely claimed in the meteorology literature that one-third of the US economy is weather-sensitive. There appears to be little, if any, justification or empirical basis for this claim, although the issue is of critical importance to the weather enterprise. Begun in October 2004, this two-year study headed by Jeff Lazo (RAL/ISSE) defined and examined the sensitivity and vulnerability of state-level economic sector productivity to weather impacts using valid economic data and modeling techniques that have not previously been used in this topic area. This research directly supports NCAR's strategic goal to "Improve understanding of the atmosphere, the Earth system, and the Sun" by undertaking interdisciplinary research to quantify the economic impacts of severe weather, the value of forecast information, and the effectiveness of warnings.

Twenty-four years of state-level economic data and historical weather observations were analyzed to estimate sectoral sensitivity and vulnerability to weather impacts such as temperature and precipitation. Eleven US economic "super-sectors" are ranked based on their degree of sensitivity to weather, states more sensitive to weather impacts, and the aggregate dollar amount of variation in US economic activity attributable to weather variability is calculated. Estimates indicate that US economic output could vary annually by about 3.4% due to weather variability, representing about $260 billion a year in 2000 dollars.

Data analysis and estimation are now complete, and research results are being written for submission to peer-reviewed journals during FY2007. The current phase of this project will be completed during the first quarter of FY2007, with drafts of two papers on project results. Estimates from this study will provide policy makers with information on the magnitude of weather variability in different economic sectors and states. This will assist decision makers to prioritize research allocations for reducing these impacts and provide a basis for understanding the economic value of current and improved weather information. This research is supported by the National Science Foundation and the National Oceanic and Atmospheric Administration.