beilman c cycle guestlecture geog401 - university of...
TRANSCRIPT
Geog 401 Climate Change SP14Lecture 4 ‐ Carbon Cycle 23 Jan 2014
Dave Beilman, UHM [email protected]
Carbon is an important elemental biogeochemical cycle
Why should we know or care about carbon and its pools and fluxes?
12C – stable carbon (light)13C – stable carbon (heavy)14C – radioactive carbon (decays over time)
‘Natural processes [affecting carbon dynamics] are linked to physical conditions, chemical reactions, and biological transformations and they respond themselves to perturbed atmospheric composition and climate change. Therefore, the physical climate system and the biogeochemical cycles of CO2, CH4 and N2O are coupled.’
Take home message
IPCC 2013
Global carbon cycle – pools and fluxes
Inverse relationship between size of pool and flux rate
Fast exchanges with atmosphere, e.g. vegetation
Big, slow exchanges with atmosphere important on long timescales, e.g. rocks
Ru
dd
ima
nE
art
h’s
Clim
ate
Fig
3-3
OM is a complex and varied mixture of organic substancesAll organic substances contain C, ~ ½ of OM is C
Global vegetation: 350-550 Gt CGlobal soils: 1500 -2400 Gt C[Atmosphere: 800 Gt C]
Organic matter and organic carbon Atmospheric CO2 concentration
Atmospheric concentrations of CO2 recently crossed 400 ppmv
Forcings of climate change
The largest contributor to the uptake in energy by the climate system is the increase in atmospheric CO2 concentration since 1750
IPC
C A
R5
(20
13)
The global carbon cycle
IPC
C A
R5
(20
13)
A global balance in fluxes between reservoirs – today’s atmosphere is out of balance owing to anthropogenic C emissions
Black – pre Industrial EraRed – post IE
Global soil C distributionAnnual near surface soil moisture
Annual temperature Summer precipitation
IPCC AR5 long‐term projections Case study: impacts of invasive species in Hawai‘i on C dynamics
Has invasion by Sphagnum palustre impacted ecosystem C processes on Ka‘ala?
Partner: O‘ahu Army Natural Resource Program
Is Sphagnum doing anything remarkable on Ka‘ala? YES Ka‘ala vs Kohala sites ‐ bioclimatic conditions
PAR
Air T
Soil T
Mean Ann Rainfall:Ka‘ala – 2016mmKohala – 2683mm
What’s next? Case study: Antarctic field campaign – Feb 2014
One of our field sites26 Dec 2013
Mahalo!
Additional reading
Intergovernmental Panel on Climate Change, Working Group 1. 2013. Chapter 6: Carbon and Other Biogeochemical Cycles.
Schlesinger, W.H. 2013. Biogeochemistry: An Analysis of Global Change. 3rd
Edition. Elsevier.