the multiple effect of increasing carbon sink (re-foresting and … · markku kulmala jaana bäck,...
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Markku Kulmala
Jaana Bäck, Timo Vesala, Veli-Matti Kerminen, Tuukka Petäjä
INAR
Faculty of Science and Faculty of Agriculture and Forestry / University of Helsinki
Finland
The multiple effect of increasing carbon sink (re-forestingand afforesting) on climate
18/02/2019 1
Acknowledgements
• ERC
• The Academy of Finland
• PEEX
• The Atmospheric Radiation Measurement (ARM) Climate Research Facility is a U.S. Department of Energy
• St1 Ltd
• INAR science community - particularly Ksenia Tabakova
Clear and ambitious vision / from deep
understanding to practical solutions
Empirical measurements and modelling /
from observations to new theories
From research to innovations /
economic growth and human wellbeing
MULTIDIMENSIONAL, MULTIDISCIPLINARY, MULTISCALE
APPROACH TO ANSWER GRAND CHALLENGES
CURRENT STATE
• Initial Conditions• Assimilation
Provides
context
Complete
the picture
Satellite data
Provides
details
Multiscale Models
Ground-based data
Nature Comment (2018), Nature 553, 21–23 Nature Comment (2018), Nature 554, 25-27
Academician, Academy Professor Markku KulmalaUniversity of Helsinki, Faculty of ScienceInstitute for Atmospheric and Earth System Research [email protected]
Academician, Professor Guo HuadongChair of DBAR The Institute of Remote Sensing and Digital EarthChinese Academy of [email protected]
Sharing big data from satellite imagery and other Earth observations
Global SMEAR and Digital Belt & Road - DBAR
INTEGRATED APPROACH:
THE GLOBAL EARTH OBSERVATORY / GLOBAL SMEAR
Current observations (see IPCC 2013) arefragmented:
1) Greenhouse gases
2) Aerosols
3) Air quality
4) Ecosystems
5) Climate
6) …
Future aspiration: Integrated approach
• To understand feedbacks
• To reduce uncertainties
• To mitigate and adapt effectively
SMEAR II-station (boreal forest, country side)
Continuous, comprehensive observations
Lakes Peatlands
Site for ICOS, ACTRIS, INGOS, EXPEER, ANAEE, LTEER, LifeWatch, WMO, EMEP, CARBOEUROPE,
NITROEUROPE, EUCAARI, PEGASOS
Forest
Over 1200different variables Urban
SMEAR II Hyytiälä
CARBON: partitioningNeedle respiration
300 g C m-2
Needle photosynthesis
1100 g C m-2
Root respiration Decomposition of
soil organic matter
Wood respiration
100 g C m-2
The net carbon
sequestration 200-250
g C m-2 a-1
Soil carbon efflux
600 g C m-2
Litter production
100 g C m-2
Respiration
~75 g C m-2
Photosynthesis
100 g C m-2
Courtesy: Pasi Kolari
CO2
Processes
Root exudates
100-200 g C m-2
Photosyntesis,
GPP VOCs
GR
CCN, CS, Accumulation
mode, AOD
Diffuse radiation
Global radiation
CO2+
+
+
+
+
+
Carbon sink
Aerosol effects
8% 6%
6%
6%1.5%
0.7%
+ 10 ppm
SMEAR II: 1996-2009
Kulmala et al., 2014, BER
FROM CARBON SINK TO AEROSOL SORCE AND BACK
What do forests do?
• Carbon sink (sometimes source)
• Decreasing albedo
• BUT THIS IS NOT EVERYTHING
• VOC source
• Aerosol particle source
• CCN source
• Makes its own clouds and precipitation
• How big forest is needed?
• What is the role of newly formed particles in the cloud activation in-situ?
• Do they alter the cloud properties / precipitation?
Petäjä, T. (2013) Science Plan Biogenic Aerosols – Effects on Clouds and
Climate (BAECC), US Department of Energy, Office of Science, DOE/SC-ARM-
13-024.
1. From gas phase
Emissions to
Aerosol particles
2. From Aerosol
particles to Cloud
droplets / Cloudss
3. From Clouds to
Precipitation
4. Feedbacks and
Interactions
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The key scientific questions:
• What is the minimum spatial scale of boreal forest that can produce its own clouds and thereby
produce its own precipitation and modify the regional water cycle and sustain forest growth?
• Under which conditions is the water cycle self-sustained on the regional scale?
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2019/2/18 15
Aerosol size
distribution
and mass
2019/2/18 16
Aerosol
chemistry
2019/2/18 17
In-situ measured CCN concentrations
increase as a function of time-over-land
2019/2/18 18
Backscattering
In-situ and ground-based remote sensing agree!
Ground-based remote sensingIn-situ
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Liquid water path
2019/2/18 20
Cloud droplet concentration
Sogacheva et al., 2005, BER
CO2
+ 8 %+ 10 ppm
THE POTENTIAL OF SMEAR CONCEPT:
GLOBAL COMPREHENSIVE FEEDBACK ANALYSIS
Kulmala et al., 2014, BER
20 largest
metropolitan areas
Arctic-Boreal PEEX area
Eastern Asian PEEX area
Amazonas
Sahara + EMME region
Africa
Cloudsaerosol effects
+ 6 %
Diffuse radiation
Global Radiation
+ 1.5 %
PhotosynthesisCarbon sink
Volatile organic compounds
+ 6 %
+ 0.7 %
How big forest is enough to make its ownprecipitation?• Time over land: ca 70-80 h
• Distance: ca 700 – 1000 km
• Needed area: 1000 km x 1000 km = 1 000 000 km²
• Sahara: 9 200 000 km²
• Siberia: 13 100 000 km²
• An excellent way to mitigate climate: re-foresting and afforesting• Carbon sink
• Aerosol source
• Makes its own clouds (-> albedo effect good for climatenor minor albedoeffect)
• Makes its own precipitation