National Assessment of Ecological C Sequestration and Greenhouse Gas Fluxes – the USGS LandCarbon Project
Zhiliang Zhu, Project Chief, [email protected]
• What is the role of carbon in global change research? What do we know about carbon dynamics nationally and globally?
• The USGS assessment: what are our objectives and approach?
• Introduce our recent work and findings, what do the findings mean to us?
Role of carbon in the world, and in the U.S.
Wikipedia: year 2000
Carbon in Ecosystems
Carbon cycle in ecosystems
Forests Wetlands
Agricultural lands Grasslands Aquatic systems
What do we know?
C stock in ecosystems estimated from various sources Annual C stock change in and
between ecosystems from EPA(Tg C)
Data are for CONUS only
What we don’t know (so well)?
What are spatial and temporal patterns and trends of the C stocks and fluxes?
How does climate change affect C stock and sequestration?
What is the role of LULC change? Land management? Natural disturbances?
USGS LandCarbon Assessment Objectives and Scope
Scope:1. Five primary ecosystems: forests,
shrub/grasslands, croplands, wetlands and aquatic (rivers, lakes, coastal waters) systems
2. Two types of assessment: baseline (current) and future projections (“forecasts”)
3. Carbon storage and sequestration; fluxes of CO2, N2O, and CH4
4. Effects of natural and anthropogenic processes (e.g. climate change, wildfire, land use change, and land management activities)
5. All 50 States
Objectives:1. To implement the 2007 Energy
Independence and Security Act (EISA), Section 712
2. To improve scientific understanding of carbon sequestration and GHG fluxes in ecosystems related to land use, using research results from USGS and other organizations
Methodology of the Assessment
• Current fire areas and GHG emissions
• Future fire areas and GHG emissions
• Current LULC maps• Future scenarios• Future LULC maps• Forest age change
Aquatic C and GHG methods
Terrestrial C and GHG modeling
Analysis, Report, Data Distribution
Input data: inventory, remote sensing, climate,
soil, land management
Monitoring R&D
Information and Products Produced Annually from 2001 to 2050
Assessment conducted at a regional scale
1st
2nd
3rd
4th
IPCC 4th Assessment Scenarios
Current and future potential LULC changes in Great Plains
Wildland fire: current and future potential
Baseline and Future Potential Carbon Trends
Forests Grasslands Ag lands Wetlands Water TotalCONUS from literature 57,000 16,000 20,000 62,000 155,000Forest Service Great Plains 2,096 USGS GP assessment 1,162 2,614 3,438 216 7,500
Current C Budget in Great Plains Region
Future LULC and C Changes in the Great Plains
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Net Changes Between Years
Lessons learned from the GP assessment
There are many science gaps that affect the overall quality of the assessment
Biogeochemical models are very limited It takes a lot of resources (time and money) to attribute
effects of carbon sequestration to climate change, land use, land management, and natural disturbances; we were unable to do a good enough job
Still no good way to quantify uncertainties
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