Organization:
Research Title: Long-Term Environmental Change
Funding Level (millions of dollars):
| FY94 | 1.6 |
|---|---|
| FY95 | 1.6 |
| FY96 | 1.6 |
Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Subcommittee on Global Change Research (100%)
(b) Environmental Issue: Climate Change (10%); Natural Variability (90%)
(c) Research Activity: System structure and function: Observing (50%);
Understanding
(50%)
Organizational Component:
National Museum of Natural History (NMNH)
Smithsonian Tropical Research Institute (STRI)
Point of Contact:
Ted A. Maxwell
Phone: 202-357-1424
E-Mail: tmaxwell@ceps.nasm.edu
Program Description:
Understanding anthropogenic modifications to the environment can be done only if
we know the natural
variability of the systems. The primary thrust of the Smithsonian's work is to improve
our
knowledge of the natural
processes involved and to continue to provide a long-term repository for present
and future
studies. Study of "deep history"
makes three unique contributions to global change research. Biotic, geologic, and
climate
systems experience natural fluctuations over decades to 105 years; therefore only
retrospective studies that consider very long time periods have a hope of distinguishing
signal from noise, and of establishing pre-human baseline conditions. Fossils and
sedimentary rocks directly record the impact of past global climate change on ecological
systems, providing the only examples we have of these phenomena and their effects.
Finally, paleontological and geological data are critical, and only, test of computer-based
simulations of past climate conditions, and so they play an important role in refining
models of climate dynamics. This program addresses most of the research priorities
outlined in the GCRP under Earth System History. Paleoclimate and paleoecology
are explicit foci of research, as are past changes in ocean circulation, ocean productivity,
and sea level.
Program Interfaces:
Studies in Paleoecology are largely based on a unique resource of the Smithsonian,
its
collections, which range from Paleontological specimens used to infer growth rates
of
species to botanical specimens that are a baseline for modern studies. We have established
an international network of collaborating scholars at private and governmental institutions.
We have sponsored and hosted international meetings and a symposium addressing the
issue of ecosystem stability on long and short time scales. Strong linkages exist
to research
at USGS and Smithsonian bureaus, as well as to those working under NSF support at
many private universities and museums.
Program Milestones:
We have preliminary data suggesting that past ecosystems may have displayed "threshold"
effects; they showed little response to climate change over long periods, then changed
rapidly over short intervals. We will concentrate studies on the rates of change,
a largely
unknown factor in the environment variability, continue studies of world's deltas,
with
emphasis on sea level change and fluvial response, continue work on a volcano data
base
and link to other shared environmental archives.
Research Description:
Long-term indicators of environmental change area studied at NMNH to understand the
natural processes and rates of ecological, oceanographic and volcanic phenomena as
they
affect the global environment, and at STRI to determine anthropogenic and other ecosystem
responses to climate change. NMNH Studies of Long Term Climate Change (100%).
These studies concentrate on the detection of past climate changes on ecological
systems,
examination of past episodes of warmer climates to establish pre-human baseline
conditions, determination of ecosystem response to sudden environmental change, and
are
used to test computer predictions of paleoclimate. This work is performed through
field
research and by using the extensive collections of fossils and other data available
through
the museum, and methods are being developed to link a customized data management
program to a graphics/map interface. Recent results include the documentation of
the effect
of sea level rise on coral reef growth, of pre-historic human colonization on island
biotas,
and of climate on vegetational diversity and structure. The Nile Delta Project,
underway
since 1985, seeks to identify paleoclimate changes through their effects on the Nile
drainage system, both on the delta and adjacent coastlines. Major ecological changes
due to
man (via the Aswan High Dam that modified irrigation and sedimentation), natural
forces
(salt water incursion and land subsidence), and desertification (changing the sediment
load
of the river) are being studied employing the sediment record in the Nile delta and
adjacent
coastlines. This work has been expanded to include other deltas of the world. Also
at
NMNH, the historical record of volcanic events on a global scale is continuously
updated
and made available to the scientific community via the Global Volcanism Network
(formerly the Scientific Event Alert Network, SEAN). A database of the world's
volcanoes and their eruptions over the last 10,000 years is maintained, as is an
archive of
maps, photographs and other documentation. The database has been an active project
for
more than 25 years, and forms the natural baseline for studies such as those dealing
with
the construction of volcanic aerosols to global warming. At STRI, we are proposing
a
program to core lakes in the Amazon basin in order to determine long-term changes
in
vegetation associated with Pleistocene climate changes in the tropics.
Research Goals:
To understand long-term indicators of global change present in the historical artifacts
and
records of the museums as well as in the geologic and botanical record at field sites.