CLIMATE CHANGE AND CORAL REEFS

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CLIMATE CHANGE AND CORAL REEFS Dr. Robert
Buddemeier Kansas Geological Survey University
of Kansas
Testimony presented to the June 27, 2002 hearing
on Implementation of the Coral Reef Conservation
Act of 2000 and the impact of climate change on
coral reefs Subcommittee on Fisheries
Conservation, Wildlife and Oceans, Committee on
Resources U.S. House of Representatives
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• Questions posed
•  
• how (has) the interplay between climate, the
  marine environment, and coral ecosystems
  changed, and (what are) the resultant and
  predicted effects?
•  
• Human society has systematically altered the
  chemical composition and dynamics of the
  atmosphere and surface ocean on a global scale,
  and has made even more dramatic changes in the
  earth surface and the costal zone at local and
  regional levels.
• The result has been an extensive loss of
  productivity, diversity, and ecosystem services.
  
• Qualitative predictions are relatively easy
  more of the same to come. Quantitative
  predictions and management are much more
  difficult, because we lack precedents for our
  present situation.
•  
• (are environmental changes and coral declines
  due to) natural climatic cycles and variations,
  or (do) these declines stem from human-driven
  factors?
•  
• On decade-to-millennium time scales, natural
  variations are nearly inconsequential compared to
  human alterations of global biogeochemical cycles
  and local environments since the 1800s.
•  
• of what importance compared to other factors
  are climate effects in coral reef declines.
•  
• Climate-change related stresses
• Are presently the dominant factor in the decline
  of those reefs not subject to direct local
  contamination or exploitation stress,
• Are increasing in their relative contributions to
  combined stresses, and
• Will continue to increase in intensity and
  importance independent of local management or
  protection actions.

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In 150 years, humans have driven atmospheric
composition well outside of the stable
multi-million year range of oscillation
Vostok ice core records
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In the space of 150 years, atmospheric
temperatures have increased not only beyond the
range of past natural variations, but also beyond
the range of uncertainty in those variations
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Northern Hemisphere Average Surface Temperature
1
C
0
-1
1000
1400
1200
1600
1800
2000
Year
Mann et al. (1999) GRL 26759-762
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Addition of IPCC projections to the observed
changes produces an even more dramatic shift for
coming decades

• We have entered a no-analog period of earth
  history
• Trends will continue for decades and are not
  easily reversed
• Accelerated climate change is, or soon will be,
  the overall dominant source of stress for coral
  reefs and other widely-distributed ecosystems

Northern hemisphere temperature history and
projection, 1000-2100 AD
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• what recommendations would you provide for
  stopping and reversing these declines?
• 1. Recognize that climate-related declines
  cannot be stopped for decades, and may never be
  reversed. Adaptation of organisms and ecosystems
  to changing climate can be helped by removal or
  avoidance of other stresses.
• We need an effective way of measuring the extent
  and nature of the biological effects of climate
  change over time, and we need to understand
  healthy systems and the nature of their response
  to different combinations of stresses.
• Protection and preservation of living organisms
  and functional ecosystems is a debt owed to
  future generations and is beneficial to those
  now alive. 
• Interagency, international, and interdisciplinary
  efforts are needed problems transcend any
  individual group of people or specific ecosystem.
•  
• other informationpertinent to the discussion.
• The United States has, within its existing marine
  refuge and sanctuary holdings, the natural
  resources needed to understand the nature of the
  global and local problems and the most effective
  management and adaptation strategies. A broadly
  integrative program should be developed to
  combine conservation, monitoring, and fundamental
  and applied research.

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Modeled baseline (ca. 1850) carbonate
saturation -- the more green it is, the more
easily corals calcify
USFWS and NOAA reef locations in the E-Central
Pacific a near-pristine transect along the
gradient of climate change
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Calculated present carbonate saturation -- the
more green it is, the more easily corals calcify
USFWS and NOAA reef locations in the E-Central
Pacific a near-pristine transect along the
gradient of climate change
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Modeled 2065 carbonate saturation -- no more
green.
USFWS and NOAA reef locations in the E-Central
Pacific a near-pristine transect along the
gradient of climate change
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• The proposed product
• An integrated network of research, conservation,
  and monitoring sites providing complementary
  transects high human impact to relatively
  climate- dominated in the Caribbean and Gulf of
  Mexico, and pristine climate dominance to
  moderate human impact in the Pacific.
• Developed from the existing NOAA and Department
  of Interior holdings and programs, with
  integration of participation from other
  government entities, science agencies, NGOs, etc.
• Global community participation, with benefits for
  marine and coastal ecosystem understanding and
  management in general as well as for coral reefs.
• Continued and enhanced conservation of our
  natural heritage.
• An affordable, practical approach to a growing
  large-scale problem, with potential for prompt
  initiation and implementation.