Prof. Dr. Almut ArnethDivision of Ecosystem-Atmosphere Interactions, KIT, IMK-IFU

Using ecosystem modelling to support assessment of Ecosystem Services and Natural

Capital due to land-based mitigation

*Quote from A. L. Jacob et al.Nature 507, 306 (20 March 2014) doi:10.1038/507306c

*Or: “Forests are more than sticks of carbon”

Concept & definition

Natural Capital: Stock of natural resources (ie., carbon stored in a forest ecosystem).

Ecosystem services: Provided through the existence of NC (and their change in time) to human societies (ie., climate regulation through carbon uptake in forests).

Carpenter et al., 2009

Typical trade-offs w.r.t. land-use for climate policies

Promotion of bioenergy

Reforestation/afforestation

Other issues related to sustainability

Depends on type & location of forest

How can we better understand climate-regulating services in relation to other ecosystem services, esp. changing through time?

Dynamic global vegetation models• Simulate vegetation distribution and ecosystem processes (natural and

managed) in response to environmental changes• State of ecosystem, natural capital and (some) ecosystem services• Changes regarding location and timing

General climate mitigation measures

Reduce benefits? (i.e. CO2 fertilisation)

Use LUC idealised (!) projections from an IAM:

• maximise BECCS

• maximise afforestation/avoid defor.

(ADAFF)• reference case (REF)

(based on RCP 2.6)

Ecosystem & NC change in response to land-use change

%-change in land-cover (2100 vs. 2000)in prep.

Year (1901-2100)

Fra

ctio

n cr

op &

pas

ture

%-change in vegetation C-pool (rel. to total C; 2100 vs. 2000)

%-change in total C-pool (2100 vs. 2000)

From a C-cycle (climate service) perspective (and for different land-cover types):

• Different scenarios of land cover change affect above-ground and total C-pools substantially

• Increase in C-pools in all scenarios: CO2 fertilisation

• Largest C increase in afforestation scenario

• Afforestation and other ecosystem services?

LUC and effects on climate-regulation services

in prep.

-20 0 20 40 60

Vegetation C TotalC ET Runoff BVOC crop NPP

%-change, various (2100 vs. 2000)

BECCS

ADAFF

REF

Changes in various ecosystem properties: beyond climate services (global total, not per different land-cover types):

• Land-based mitigation will always also affect other important NC and ecosystem services (yields, ET/cooling, runoff/flood and irrigation)

• Open question: how would biodiversity scenarios interact with natural capital/ESS?

Response mostly to area change (no assumptions about intensification or other technological changes to yields)

LUC and effects on other ecosystem properties and services

Air quality & climateIrrigation, flood, water quality

Climate; some effects on habitat diversity

Forests are more than sticks of carbon – and ecosystems are more than carbon dumps

• Different ecosystems have very different functioning, natural capital and derived ESS

• Side-effects of land-based mitigation identify & manage unexpected outcomes (trade-offs but also co-benefits)

• Challenge: governance of land management that enhances both climate regulation, other sustainability goals, and biodiversity

www.LUC4C.eu