Global ozone and threats to food production.

Frank Dentener European Commission- JRC

Co-chair TF HTAP

International Conference on Atmospheric Chemistry and Agricultural Meteorology

Frank Dentener1, Gina Mills2, Lisa Emberson3, Maurits van den Berg1

1 European Commission, JRC, Italy,

frank.dentener@jrc.ec.europa.eu 2 Centre for Ecology and Hydrology, UK 3 Stockholm Environment Institute, University of York, UK

2

• Ozone: why, when, and what are the issues? • Interactions of ozone and plants • How is ozone changing, HTAP • What can we do about it?

Royal Society (2008)

• Current day O3 concentrations are now high in many agriculturally

important regions ....

• Monitoring, models, and satellite information

Ground level ozone pollution –where?

Ground level ozone pollution –when?

Rural location in the UK Regional / local emissions

contribute to peak ozone

concentrations

Can reach 200 ppb and over

Global emissions contribute

to global - 30 to 40 ppb

and rising in many regions

• The photochemical formation and secondary nature of O3 makes it

an important summertime and rural air pollutant…

• In tropical regions seasonality of ozone is more connected to wet-

and-dry seasons

Why do we worry about tropospheric ozone?

5

Ozone is one the most harmful air pollutants: •Ozone is damaging agricultural crops and natural vegetation •Tropospheric ozone is an important climate gas warming the atmosphere. •Levels continue to exceed air quality thresholds to protect public health •In Europe: peak ozone is going down, but mean ozone levels are not.

In ground-level air, ozone is a pollutant formed by sunlight-driven chemical reactions involving CO, VOC, NOx from vehicle exhausts, industry but also from CH4 from agriculture and other sources

NOx

CO

VOC + CH4

Ground level ozone pollution – issues.

Ozone

Apoplast

Reactive Oxygen Species (ROS)

Chain reaction (including hydroxyl radical,

superoxide)

Increased repair respiration

Anti-oxidant defence mechanisms triggered

Cell membrane damage

Overwhelmed

Reduced growth

Direct effect on chloroplasts

Resources diverted away from growth and seed production

Cell death

Reduced functional leaf area

Reduced yield

Decrease photo- synthesis

Bottomline: Even if you don’t see it, O3 can affect crop growth

Courtesy: Gina Mills

Mechanism of O3 damage

O3

O3

Key concerns of ozone for agriculture

I. Leaf damage by ozone

II. Growth reductions

III. Yield quantity and quality reductions

IV. Fertilizer efficiency reduced

V. Drought tolerance reduced

VI. Forage quality

VII. Pests & Diseases

VIII. Interactions with climate change

Key concerns for agriculture I. Leaf damage by ozone

Wheat, Europe

Spinach, Europe

Source: J. Bender

Source: G. Mills Incidences of O3 injury in

the field, 1990 – 2006

Especially relevant for horticulture

e.g. salad leaf crops

(Mills et al., 2011,

Global Change Biology)

Key concerns for agriculture II. Growth reductions

Wheat Rice

Plants grown in ambient air with high levels of O3 pollution

Plants grown in filtered air (pollutant free), Lahore, Pakistan

Key concerns for agriculture III. Yield quantity and quality

reductions

r² = 0.59

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 20 40 60 80 100 120 140

Rel

ativ

e yi

eld

Ozone, 7h mean, ppb

Wheat

7 hour mean O3 concentration

(ppb)

--- 5 % loss.

Rela

tive y

ield

0 10 20 30 40 50

Soybean

Wheat

Rice

Peas and beans

Maize

Oilseed Rape

Alfalfa

Tomato

Potato

Sugar beet

Barley

Lettuce

Threshold ozone conc (ppb)Threshold 7 hour mean O3

concentration (ppb)

Mil

ls &

Harm

ens,

2011,

ICP V

egeta

tion

Food S

ecuri

ty R

eport

,

htt

p:/

/icpvegeta

tion.c

eh.a

c.u

k/

Threshold for significant yield effects

Ozone exposure experiments in

Sweden

Varanasi, India

Winter wheat (Nov to April) RY = 90-

75%

Rice RY = 86-84%

Indian mustard RY = 92–86%

Palak RY = 78 %

Soybean (?) RY = 89%

Allahabad, India

Mung bean (Dec to March) RY = 70%

Lahore, Pakistan

Winter wheat (Nov to May) RY = 69-53%

Spring wheat (Nov to April) RY = 82 to 52 %

Rice (May to Nov) RY = 71 to 53%

Mung bean RY = 50%

Soybean (Aug to Oct / Feb to May) RY = 68 to 26 %

Yangtze River Delta, China

Rice (July to Oct) RY = 92%

Tokyo, Japan

Rice (April to Sept) RY = 80%

Klang Valley, Malaysia

Rice (Oct to Jan) RY = 97 to 94%

Thailand

Rice (?) RY = 94 to 70%

Crop yield commonly improved by around 5-30% by filtration of

air pollution from plant micro-climate

ICP Vegetation reports

(2011, 2014)

Observations of ozone damage in Asia

• The fraction of N (P & K) added that ends up in grain is negatively

affected by ozone – leading to additional environmental problems

• Adding more N fertilizer is not a good solution to the ozone problem,

as it comes with additional environmental problems

Pleijel, Feng et al., pers. Comm.

Key concerns for agriculture IV. Fertilizer efficiency

reduced

Leontodon hispidus

r2 = 0.43, p = 0.109

Dactylis glomerata

r2 = 0.66, p = 0.042

0

50

100

150

200

250

300

350

400

450

0 20 40 60 80 100 120

Seasonal mean O3 conc. (24h, ppb)

Sto

ma

tal

co

nd

uc

tan

ce

(m

mo

l m

-2 s

-1)

Stomatal conductance

Key concerns for agriculture V. Drought tolerance reduced

• Ozone reduces drought tolerance in

agricultural species by interfering with

hormonal control.

• Increase in stomatal conductance

1Mills et al., 2009; 2, 3 Wilkinson and Davies (2009, 2010)

R2 = 0.31,

p = 0.15

R2 = 0.75,

p = 0.005

0

25

50

75

100

125

150

0 20 40 60 80

AFst0 (mmol m-2)

Bio

mass (

% o

f 34 p

pb

tre

atm

en

t)

Shoot

Root

Biomass Allocation

• Also a affects C allocation - decrease in

root biomass further limiting access to soil

water

Concentration-response relationships to perform risk

assessments to estimate yield losses...

Van Dingenen et al, 2009

• Year 2000 global economic losses estimated to cost $14-26 billion

• For economies largely based on agriculture , O3 induced damage is

estimated to offset a significant portion (20 – 80%) of the year 2000 GDP

growth rate.

• Community is moving away from AOT40 or similar to flux based approaches.

Tang et al (2013)

How will ozone affect wheat yield across Asia?

• Based on modelled ozone uptake (POD12), ozone pollution is predicted

to reduce wheat yield by 10.3% in China and 9.7% in India in 2000

• Losses predicted to increase by a further 8.9 and 6.4% respectively in

2020

2000 2020

Tang et al., 2013

Photosynthesis

Senescence

Leaf area index

Genotype

coefficients Temperature

Radiation

Assimilates Conversion Partitio-

ning

Leaves

Stems

Repr. organs

Roots

Actual transpiration

Potential transpiration

Respiration

(repair of damage)

?

Model of crop growth

Interaction with O3

Photosynthesis

Senescence

Leaf area index

Genotype

coefficients Temperature

Radiation

Assimilates Conversion Partitio-

ning

Leaves

Stems

Repr. organs

Roots

Development rate

Development stage

(Daylength)

Actual transpiration

Potential transpiration

Respiration(repair

of damage)

?

Model of crop growth

Integration over cropping season gives biomass and grain yield.

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Agro-met and management

Factors

• Temperature

• Precipitation

• Radiation

• CO2,

Climate

• Irrigation

• Fertilization

• Varieties

• Sowing date

• Pests, diseases

Management

Soil

• H2O

• C, N, P, K

Usual concerns of agronomist: •Frost kill (hardening/vernalisation) •Is there enough water during flowering

Potential/water limited yield •Fertilizer/nutrient limitation •Avoiding heat stress •Harvest conditions

How does ozone play into this? •Is ozone hidden in the calibration/parameterisation? •Ozone trends?

Winter wheat development stages

Ewert and

Porter, 2000

Integrated effects on target variables

Modelling ozone effects

Comparison with

observations

Climate chamber, cv. Wembley OTC, cv. Minaret

• Open-top and climate chamber experiments • Biomass for O3 and CO2 experiments well predicted • Overall significance not well known

• Ozone pollution is a ‘hidden threat’ to world’s food production

causing 5 to 30% yield losses in ‘hot-spot’ regions. Many food

crops are ozone sensitive including rice, wheat and pulses

• Ozone affects Nitrogen use efficiency, drought tolerance,

resistance to pests & diseases, forage quality

• First attempts to include ozone in crop growth models look

promising. Not too many parameters- well tested for wheat.

• Lots of open questions: other crops, role of varieties

(genotype), interactions with meteorology (heat stress,

drought)

• Links between agronomic and atmospheric impact communities

needs to be strengthened. (AgMIP, ISIMIP, HTAP, ICP Veg)

• Adaptation (agricultural management) e.g. crop breeding for

varieties that are not sensitive to ozone, seasonal forecasting of

ozone episodes

• Large scale significance? Does ozone play a role in the yield

gap?

mid summary

What is HTAP?

21

www.htap.org

Task Force on Hemispheric Transport of Air Pollution

Established in 2004 by the UNECE Convention on Long-Range Transport Air Pollution An expert group of scientists across the world studying hemispheric transport of air pollution

Examine transport of air pollution across the Northern Hemisphere

Assess potential emission mitigation options available inside and outside the UNECE region

Assess their impacts on regional and global air quality, public health, ecosystems, near-term climate change

Collaboration and outreach

Remote measurements of ozone in Europe, East Asia and Rest of the world

Cooper et al., 2014

Ozone trends

Ozone increases in Europe prior to 1990

Large increases in Asia and western America

Air pollution

In North America and Europe NOx emissions have gone down with ca. 30 % in the last 2 decades.

… but in Asia increasing by 150-300 % !

Sciamachy Tropospheric NO2

24

Lower troposphere

Mid-upper troposphere

Pathways of transport hemispheric air pollution

Stohl et al, 2004 5

North America, Europe, South Asia and East Asia cover ca. 60-70 % of human-related emissions

Within one month the atmosphere in the Northern Hemisphere is mixed.

Ozone produced in Asia is transported to North America, from North America to Europe etc.

NA EU

EA SA

A special case is methane which stays about 10 years in the atmosphere, and is both a greenhouse gas and an air pollutant.

Hemispheric transport

Total O3

change

Within EU

Outside of EU

Methane

HTAP attribution of O3 changes in Europe

NA EU

EA SA

Wild et al, ACP, 2012

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Annual average - large region –global models

Largest O3 (6 ppb) decreases before 1980;

small reductions in O3 during 1980-2000

O3 reductions attributable to EU emissions

compensated by increasing emissions

elsewhere

Important contribution from CH4 30-50 %

Taken together changes in O3 from outside

Europe and CH4 are larger than within EU (60-

70 % of total)

External O3 becomes more important when

‘local’ sources are more regulated.

Hemispheric transport more important at

‘lower’ concentrations

26

Observations from a global network of CH4 indicate continuous increases over the last two centuries

Small interruption but increasing again

Methane observations

http://edgar.jrc.ec.europa.eu Agricultural regions in North and South America, Europe, South Asia, China

Fossil fuel production regions

http://edgar.jrc.ec.europa.eu

Methane anthropogenic emissions

28

There are many sources of methane: agriculture (rice production, manure, cattle) contributes ca. 40 % of the man-made emissions

About half of the methane emissions comes from natural sources (not in figure), which may increase due to climate change.

Methane emission trends

Fuel use and

production

Waste

Agriculture

No Further Control (NFC)

Current Legislation (CLE)

Maximum Feasible Reduction (MFR)

2010 2050

NFC: What are the benefits of implementing current policies in terms of health, ecosystems, and climate impacts?

MFR: What technology and policy options will be available (at a reasonable cost) to further mitigate pollution problems in the future?

CLE: Given current policies,

what are emissions likely to be in the future?

Policy Relevant Questions

Future: HTAP benchmark emission scenarios

GAINS

30

O3 changes in Europe for HTAP global air pollution scenarios

Wild, Klimont et al, 2015

Total surface

O3 change

Within EU

Outside of EU

Methane

HTAP scenarios (ECLIPSEv5a)

NFC No further control

CLE Current Legislation

MFR Maximum Feasible Reductions

For Europe:

Regional controls can still bring down

ozone, but requires ambitious air pollution

policy

Ambitious air pollution policy elsewhere

may further help, especially in the US.

Methane emission reductions are going to

be crucial for reducing ozone.

Methane is included in climate policies, but

we will need to reduce it also for reducing

ozone air pollution.

Reducing methane will require strong

collaboration with countries in Asia

31

In Europe and North America peak ozone is declining. Ozone concentrations

look likely to continue to increase in Asia over the coming decade

The contribution of hemispheric O3 to local pollution is increasing.

International efforts to reduce tropospheric ozone, will facilitate achievement of local air quality objectives.

UNECE’s TF HTAP and ICP vegetation brings scientists together to inform policy on the role of hemispheric air pollution, their impacts, and mitigation options. A portfolio of mitigation options is emerging- it is clear that emission reduction of CH4 (producing O3) is going to be very important- with important benefits from (and for) climate policies.

Reducing ozone will have large benefits for agriculture, and agriculture is also key to reducing methane and other air pollution emissions.

Global institutions (WMO, UNEP, FAO, UNECE, CCAC … ) can help with raising awareness regarding options and benefit of reducing emissions, informing and facilitating international agreements.

Take home messages

32

20 years of in support to the implementation and

monitoring of Common Agricultural Policy

Thank you for your attention!

33

For Discussion session

34

• Little awareness of agriculture as a source of and being affected by air pollution

• Increasing contribution to AP from agriculture, but not much happening despite cost-effective measures in particular for NH3

• Methane is partly from agriculture, GHG

and O3 precursor. O3 damages agriculture.

• Reducing methane is win-win.

• What to do? Continuing outreach and research Early warning systems;

demonstration Smart technologies to measure AP Inclusion of air pollution in

environmental labelling Rewarding innovation

https://ec.europa.eu/jrc/en/event/conference/sustainable-food-production-and-air-

pollution

Discussion rather Europe focussed

‘Sustainable Agriculture and Air Pollution’

10 July 2015; EXPO, Milan, Italy

Reports to UN LRTAP Convention on impacts of

air pollutants on crops & natural vegetation

35 European countries and USA, over 60

Institutes and 200 scientists participate

Outreach to eastern Europe, Asia (including

India), South Africa and the Caribbean

ICP Vegetation Participating

Institutes in

Europe

How can we collate this information?

http://icpvegetation.ceh.ac.uk/

Examples of ICP Vegetation Thematic

Reports

What is HTAP?

36

www.htap.org

Task Force on Hemispheric Transport of Air Pollution

Established in 2004 by the UNECE Convention on Long-Range Transport Air Pollution An expert group of scientists across the world studying hemispheric transport of air pollution

Examine transport of air pollution across the Northern Hemisphere

Assess potential emission mitigation options available inside and outside the UNECE region

Assess their impacts on regional and global air quality, public health, ecosystems, near-term climate change

Collaboration and outreach

‘Sustainable Agriculture and Air Pollution’

10 July 2015; EXPO, Milan, Italy

Climate Smart Agriculture (CSA)

• CSA - agricultural management

practices that reduce GHG

emissions and enhance

productivity & livelihoods

• CSA could focus on CO2, CH4,

N2O but also aerosols and ozone

• Aerosols have a local/regional influence on climate (meteorology) e.g. effect of

aerosol on precipitation patterns and solar radiation (dimming)

• Ozone has a direct toxic effect on seasonal productivity

Mitigation options: Emission reductions

‘Plants and the changing Environment’

9-12 June 2014; Monterey, California, US

Similar results found that modern wheat cultivars are more ozone-sensitive

(Barnes et al., 1990; Biswas et al., 2008; Pleijel et al., 2006; Velissariou et al.,

1992).

Adaptation options: Raised awareness in crop

breeding

Selection of higher yielding varieties tend to have higher gas exchange

and hence greater ozone uptake

Osbourne et al. (in prep) Slo

pe o

f re

sponse

functi

on

Year of release

‘Plants and the changing Environment’

9-12 June 2014; Monterey, California, US

Adaptation options: Early warning systems

Early warning system of ozone episodes in place in

Cuba since 1992:

• Farmers get 5 day warning of high

ozone

• Watering withheld

• Damage to garlic reduced from 73% to

2%

Source: Jésus Ramirez

Five key threats

The WAGES of too much nitrogen Water quality Air quality Greenhouse balance Ecosystems Soil quality

European Nitrogen Assessment, 2011

Plus better food & energy supply

Joining up nitrogen: addressing the barriers-to-change

The car and the exhaust pipe…

Splash Plate Spreader

- 1950s technology

Trailing Shoe Slot Injector

Trailing Hose

“20:20 for 2020” 20% better NUE: saving 20 Mt N per yr by 2020

Benefits expressed here as N saving / ha per year (Full-chain NUE)

N saving as kg N per ha per yr

Bottom line for the Green Nutrient Economy ($billion/year)

Net Benefit 170= Fert Saving 23 + Env+Health 160 – Implementation 12

44

https://ec.europa.eu/jrc/en/event/conference/s

ustainable-food-production-and-air-pollution