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Centennial and Millennial climate-carbon cycle feedback analysis for future anthropogenic climate change

Chowdhury, Dipa Paul LU (2013) In Student thesis series INES NGEM01 20122
Dept of Physical Geography and Ecosystem Science
Abstract
Increased anthropogenic emission of CO2 is alleged to impact the climate system in the future, which will affect the feedback between carbon cycle and climate change. In this project, a climate-carbon cycle feedback analysis has been conducted by using long simulated time series (2001 – 3000) data, derived from the Max-Planck-Institute / University of Wisconsin-Madison Earth System Model (MPI/UW ESM). This complex Earth system model was forced by historical emissions of CO2 and by three IPCC SRES scenarios, A2, A1B and B1 till 2100, then for the remainder (2100-3000), an exponential decrease of CO2 emissions was assumed. The analysis has been calculated for the 21st century and for the year 3000, to study the short term (100 year) and long... (More)
Increased anthropogenic emission of CO2 is alleged to impact the climate system in the future, which will affect the feedback between carbon cycle and climate change. In this project, a climate-carbon cycle feedback analysis has been conducted by using long simulated time series (2001 – 3000) data, derived from the Max-Planck-Institute / University of Wisconsin-Madison Earth System Model (MPI/UW ESM). This complex Earth system model was forced by historical emissions of CO2 and by three IPCC SRES scenarios, A2, A1B and B1 till 2100, then for the remainder (2100-3000), an exponential decrease of CO2 emissions was assumed. The analysis has been calculated for the 21st century and for the year 3000, to study the short term (100 year) and long term (1000 year) climate-carbon cycle feedback. In addition, there is not only a difference in time period but also centennial time scale represents a transient state where CO2 forcing continues to increase; on the other hand millennium time scale represents a near equilibrium state of the Earth system against CO2 forcing. For both the centennial and millennial time scale, this complex Earth system model results in positive feedbacks between carbon cycle and climate change for all three scenarios (A2, A1B, and B1). The magnitude of this positive feedback will be stronger by the end of the millennium (3000). This positive feedback clearly indicates that climate change will reduce the carbon uptake by the Earth system due to the climate carbon cycle feedback, thus there will be more remaining CO2 in the atmosphere which is able to produce an additional warming on climate system. The relative magnitude of this positive feedback varies depending on scenarios. For the A2 scenario, this positive feedback has increased by 9% and 39% for 21st century, and for the year 3000, respectively compared to the 20th century. For the A1B scenarios, it has increased by 10% and 30%, respectively, and for the B1 scenario, it has increased by 7% and 14% correspondingly. (Less)
Abstract
Popular science
Carbon cycle has great importance in all time scales for its inter-connected relation and response with climate system. Increased anthropogenic emission of CO2 is alleged to impact the climate system in the future, which will affect the feedback between carbon cycle and climate change. In this project, a climate-carbon cycle feedback analysis has been conducted by using long simulated time series (2001 – 3000) data, derived from the Max-Planck-Institute / University of Wisconsin-Madison Earth System Model (MPI/UW ESM).
This complex Earth system model was forced by historical emissions of CO2 and by three IPCC SRES scenarios, A2, A1B and B1 till 2100, then for the remainder (2100-3000), an exponential decrease of CO2... (More)
Popular science
Carbon cycle has great importance in all time scales for its inter-connected relation and response with climate system. Increased anthropogenic emission of CO2 is alleged to impact the climate system in the future, which will affect the feedback between carbon cycle and climate change. In this project, a climate-carbon cycle feedback analysis has been conducted by using long simulated time series (2001 – 3000) data, derived from the Max-Planck-Institute / University of Wisconsin-Madison Earth System Model (MPI/UW ESM).
This complex Earth system model was forced by historical emissions of CO2 and by three IPCC SRES scenarios, A2, A1B and B1 till 2100, then for the remainder (2100-3000), an exponential decrease of CO2 emissions was assumed. The analysis has been calculated for the 21st century and for the year 3000, to study the short term (100 year) and long term (1000 year) climate-carbon cycle feedback. In addition, there is not only a difference in time period but also centennial time scale represents a transient state where CO2 forcing continues to increase; on the other hand millennium time scale represents a near equilibrium state of the Earth system against CO2 forcing. For both the centennial and millennial time scale, this complex Earth system model results in positive feedbacks between carbon cycle and climate change for all three scenarios (A2, A1B, and B1). The magnitude of this positive feedback will be stronger by the end of the millennium (3000). This positive feedback clearly indicates that climate change will reduce the carbon uptake by the Earth system due to the climate carbon cycle feedback, thus there will be more remaining CO2 in the atmosphere which is able to produce an additional warming on climate system. The relative magnitude of this positive feedback varies depending on scenarios. For the A2 scenario, this positive feedback has increased by 9% and 39% for 21st century, and for the year 3000, respectively compared to the 20th century. For the A1B scenarios, it has increased by 10% and 30%, respectively, and for the B1 scenario, it has increased by 7% and 14% correspondingly.
An important aspect revealed from the millennium timescale simulations of this complex MPI/UW ESM is that the Earth system can respond strongly towards climate change when it reaches an equilibrium state. However, the result from other simulations which are based on 21st century does not reveal the full extent of feedback as Earth system has not reached in its equilibrium state. Therefore, longer timescale simulation (millennium or more) is necessary to study the full extent of climate-carbon cycle feedback which may help the policy makers to implement the rules and regulations on CO2 emissions. (Less)
Please use this url to cite or link to this publication:
author
Chowdhury, Dipa Paul LU
supervisor
organization
course
NGEM01 20122
year
type
H2 - Master's Degree (Two Years)
subject
keywords
sensitivity, scenario, climate change, earth system model, feedback, carbon cycle, Physical Geography and Ecosystem Science
publication/series
Student thesis series INES
report number
289
language
English
id
4092421
date added to LUP
2013-10-25 10:47:24
date last changed
2013-10-25 10:47:24
@misc{4092421,
  abstract     = {Popular science
Carbon cycle has great importance in all time scales for its inter-connected relation and response with climate system. Increased anthropogenic emission of CO2 is alleged to impact the climate system in the future, which will affect the feedback between carbon cycle and climate change. In this project, a climate-carbon cycle feedback analysis has been conducted by using long simulated time series (2001 – 3000) data, derived from the Max-Planck-Institute / University of Wisconsin-Madison Earth System Model (MPI/UW ESM). 
This complex Earth system model was forced by historical emissions of CO2 and by three IPCC SRES scenarios, A2, A1B and B1 till 2100, then for the remainder (2100-3000), an exponential decrease of CO2 emissions was assumed. The analysis has been calculated for the 21st century and for the year 3000, to study the short term (100 year) and long term (1000 year) climate-carbon cycle feedback. In addition, there is not only a difference in time period but also centennial time scale represents a transient state where CO2 forcing continues to increase; on the other hand millennium time scale represents a near equilibrium state of the Earth system against CO2 forcing. For both the centennial and millennial time scale, this complex Earth system model results in positive feedbacks between carbon cycle and climate change for all three scenarios (A2, A1B, and B1). The magnitude of this positive feedback will be stronger by the end of the millennium (3000). This positive feedback clearly indicates that climate change will reduce the carbon uptake by the Earth system due to the climate carbon cycle feedback, thus there will be more remaining CO2 in the atmosphere which is able to produce an additional warming on climate system. The relative magnitude of this positive feedback varies depending on scenarios. For the A2 scenario, this positive feedback has increased by 9% and 39% for 21st century, and for the year 3000, respectively compared to the 20th century. For the A1B scenarios, it has increased by 10% and 30%, respectively, and for the B1 scenario, it has increased by 7% and 14% correspondingly.
An important aspect revealed from the millennium timescale simulations of this complex MPI/UW ESM is that the Earth system can respond strongly towards climate change when it reaches an equilibrium state. However, the result from other simulations which are based on 21st century does not reveal the full extent of feedback as Earth system has not reached in its equilibrium state. Therefore, longer timescale simulation (millennium or more) is necessary to study the full extent of climate-carbon cycle feedback which may help the policy makers to implement the rules and regulations on CO2 emissions.},
  author       = {Chowdhury, Dipa Paul},
  keyword      = {sensitivity,scenario,climate change,earth system model,feedback,carbon cycle,Physical Geography and Ecosystem Science},
  language     = {eng},
  note         = {Student Paper},
  series       = {Student thesis series INES},
  title        = {Centennial and Millennial climate-carbon cycle feedback analysis for future anthropogenic climate change},
  year         = {2013},
}