Nitrogen boundaries global and regional perspectives€¦ · Nitrogen boundaries – global and regional perspectives Climate and Clean Air Commission, Vienna The Nitrogen Cascade

November 2015

Dr Sarah Cornell

Nitrogen boundaries – global and regional perspectives

Climate and Clean Air Commission, Vienna The Nitrogen Cascade

• Environmental change is global, not just local

– we are all part of the system

• Boundaries are system features

• The system is unavoidably human

• Nitrogen boundaries are unavoidably complex

Foley et al. 2005. Global consequences of land use. Science 309, 570-574 doi: 10.1126/science.1111772

Pastures and rangelands Croplands

Land cover is changing

http://www.unep.org/dewa/ vitalwater/article42.html

Water use is changing

Declining availability

Increasing withdrawals

Ecosystems all around the world are changing

WWF 2006 State of the world’s natural land habitats

Bounford.com and UNEP/GRID-Arendal, www.grida.no/graphicslib 1522.

Ecosystems all around the world are changing

WWF 2006 State of the world’s natural land habitats

Bounford.com and UNEP/GRID-Arendal, www.grida.no/graphicslib 1522.

“…large-scale loss of biodiversity is likely to occur in a 4°C world, with climate change and high CO2 driving a transition of the Earth's ecosystems

into a state unknown in human experience.” World Bank “Turn down the heat” 2012

https://www.vets.ucar.edu/vg/NGCM/movies/ngcm_co2so2.mpg

The chemistry of the atmosphere is changing

Excellent animations of model output and satellite data here: https://www.vets.ucar.edu/vg/categories/chemistry.shtml

Visualization and Enabling Technologies Section, UCAR: https://www.vets.ucar.edu/vg/index.shtml

https://youtu.be/d8sHvhLvfBo IPCC AR5 WG1 Summary for Policy Makers 2015 - www.climatechange2013.org

Earth’s physical climate is changing

Gruber & Galloway 2008. An Earth-system perspective of the global nitrogen cycle. Nature 451, 293-296, doi:10.1038/nature06592.

Biogeochemical cycles are changing

Human perturbation

Atmosphere

Land Ocean

Image: ©

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‘Planetary Boundaries’ – red alerts on a global dashboard

Rockström and 27 co-authors (2009) ‘A Safe Operating Space for Humanity’: research article in Ecology & Society, discussion article in Nature.

Steffen and 17 co-authors (2015) ’Planetary Boundaries: guiding human development on a changing planet’: published in Science www.sciencemag.org/lookup/doi/10.1126/science.1259855

Urgent issues – Bend these curves!

• Climate change and ocean acidification (mainly due to CO2 emission)

• Biodiversity loss and ecosystem degradation

• Perturbed biogeochemical cycling (release of N and P)

• Land use and land cover change

• Systemic chemical pollution

• Freshwater abstraction

• Altered atmospheric physics and chemistry (aerosol loading, stratospheric ozone)

• Interacting pressures, building up fast

Climate

change

Biodiversityloss

PerturbedN&Pcycles

Chemic

alpollu

on

Wateruse

Landtransform

aon

Oceanacidificaon

Atmosphericaerosols

The planetary boundaries concept builds on knowledge about global processes

that already present global risks

Issue Global assessments Policy structures

Climate change

IPCC AR 1990, 1995, 2001, 2007, 2014; SRES; UNHDR…

IPCC, UNFCCC SBSTA Many international conventions

Ecosystem change

MA 2005; CBD GBO1-3; UNEP GEO1-5; TEEB; FAO…

IPBES and CBD SBSTTA CBD, CITES, other conventions

Biogeochemical change

UNEP GPNM 2013; WMO/IAEA/UNEP GESAMP

INI, GPNM, WHO, FAO, WMO, IPCC, GPRI. Several conventions.

Chemical pollution

UNEP AMAP and other regional

SETAC, SCI, WHO-IFCS, Many conventions.

Nykvist et al. (2013) National responsibility (SEPA/SEI/SRC); Cornell and Downing (2014) Environment, Absolute?

• Global perspective – flagging the need to assess and respond to human perturbations

• Planetary concerns – an ‘Earth system’ view (with a social-ecological resilience slant)

• Precautionary – using scientific insight to set ‘safe operating boundaries’ to avoid disruptive risks

Why has the concept captured international attention?

Current approaches – and dilemmas – in quantifying nitrogen boundaries

• Rockström et al. (2009): N = 35 Tg N fixation yr-1

• de Vries, W. et al. (2013): N = 20-130 Tg N fixation yr-1 (depending on concern)

• Steffen et al. (2015): N to avoid eutrophication = 62 Tg N yr-1, N based on P = 73 Tg N yr-1

• Seitzinger et al. (IARU/in review): 250 Tg N fixation yr-1

• Running S (2012) - increases in NPP are possible with less (not more) nutrient and water application

• Dearing et al. (2013) – regional boundaries could be defined taking regional thresholds into account

• Carpenter, S. and Bennett, E. (2011) – several approaches to boundary setting might need to be used together

2

1

Critical N or P

fixation

Critical N or P

concentrations

Critical N or P losses

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Different methodologies can and will be used

De Vries et al. 2013

But methodologies (and boundaries)

also depend on the definition of the system

Rockström et al 2009: ‘Turn off the tap’ of anthropogenic perturbation

De Vries et al 2013: Avoid the worst impacts of anthropogenic perturbation

World Hunger (ourworldindata.org)

Seitzinger (and de Vries et al 2013): Meet global demand for food

The ‘Bretherton Diagram’ (ESSC NASA Advisory Council1988) What is the ‘Earth system’?

Physical dynamics

Biologically mediated dynamics

Integration Predictive power

Assessing global budgets (with models too)

Modelling global dynamics (with data too)

Biogeochemical cycling information – many types, many scales, many uses

(Cornell and Downing/PTB (2014) - Quality infrastructure of global change science)

Timeframes of data acquisition

Spat

ial s

cale

s o

f in

form

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Many are now calling for a global nutrient assessment. www.nine-esf.org/ENA, www.initrogen.org/sites/default/files/documents/files/ONW.pdf

The Nitrogen ‘Planetary Boundary’ – Steffen et al. 2015

High spatial heterogeneity – N use, impacts, risks

Living processes make prediction difficult – and human decision-making makes prediction unreliable

• All available information is still not enough Complex dynamic systems need plural, responsive sensing.

• Both local and global processes matter Both need to be understood – but methods designed for the local level may fit poorly with methods for tracking systemic change at the global level.

• Ecosystem change is now a human process People need to participate in ecological assessments, and ecosystems need to be explicitly included in societal assessments.

• Human wellbeing depends on ecological integrity Ecological change on today’s scale has consequences for societies. (And most projected ecological equilibria in the context of current ecosystem change are hardly desirable states for human beings.)

Precaution – Provisionality – Participation

Literature:

Rockström et al. (2009) Planetary boundaries: exploring the safe operating space for humanity. Ecology and Society 14(2): 32. http://www. ecologyandsociety.org/vol14/iss2/art32 (and discussion article in Nature).

Steffen et al. (2015) Planetary Boundaries: guiding human development on a changing planet. Science www.sciencemag.org/lookup/doi/10.1126/science.1259855

de Vries, W. et al. (2013) Assessing planetary boundaries related to food security and adverse environmental impacts. COSUST 5: 392–402

Running S (2012) A measurable planetary boundary for the biosphere. Science 337 1458-1459

Dearing et al. (2013) Safe and just operating spaces for regional social-ecological systems. Global Environmental Change 28 227-238

Carpenter, S. and Bennett, E. (2011) Reconsideration of the planetary boundary for phosphorus. Environmental Research Letters. doi: 10.1088/1748-9326/6/1/014009

Cornell S.E. and Downing A.S. (2014) Environment Absolute? Quality infrastructure of global change science. PTB/Stockholm Resilience Centre.

[email protected]

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Science Policy Decision

landscape Climate Earth system

knowledge, local gaps

Global agreement on targets

and metrics

Big science

Biodiversity Local knowledge, system gaps

Global agreement on targets

and metrics

Concerned coalitions

Biogeochemistry Gaps in local and system knowledge

Partial regional agreements,

emerging issue

Many different players

Chemical pollution Local knowledge, system gaps

Partial agreements, weak metrics

Big business

Science for real world use?

Strong policy interest in ‘safe operating space’ science: UN GSP’s ‘Resilient People, Resilient Planet’ (2012), UN Rio+20, UNEP GEO5 (2012), national assessments (Sweden, Switzerland, South Africa, Germany), EEAC discussions, LCA

researchers, green investors, UN Sustainable Development Goals (planetary boundaries processes are the focus of goals 6, 13 and 15, others are included in targets for goals 3, 11, 12, 13 and 14)

Cornell and Downing (2014) Environment, Absolute? (PTB)