SLCPand other air pollutants:

an introduction forpolicy makers

Jun-ichi KurokawaAsia Center for Air Pollution Research (ACAP), Niigata, Japan

High Level Sub-regional Consultation on Advancing Action on Short-Lived Climate Pollutants (SLCPs)

In Southeast and Northeast Asia 19 Aug 2014, Bangkok, Thailand

Background

Regional shares of global anthropogenic emissions of NOx and CO2 in 2008(EDGAR 4.2 for NOx; CDIAC for CO2)

Emissions of air pollutants and green house gases in East Asia covering Northeast and Southeast Asia have already exceeded those in European and North American continent.

This situation brings about not only serious urban and regional air pollution, but also prompted concerns on emissions in East Asia from the view of global climate change.

NOx CO2

What are Short-Lived Climate Pollutants (SLCPs)?UNEP & WMO (2011)

Reduction of CO2 emissions does not help to mitigate climate change until 2050.

Reduction of emissions of BC and CH4 will bring a relatively rapid climate response.

Decrease of SLCPs coupled with CO2 could lead to both the mid-term (2030-50) mitigation of climate change and the 2 capping in 2100.℃Major SLCPs Lifetime

Black Carbon (BC) Days

Methane (CH4) 12 years

Hydrofluorocarbons (HFCs) 15 years

Tropospheric Ozone (O3) Weeks

Long-lived Climate Pollutants (LLCPs)CO2: 60% < 100 yr; 25% > 1000 yr

SLCPs are agents which have relatively short lifetime in the atmosphere and have a warming influence on climate.

Black Carbon (BC)BC is a tiny black particle and major component of PM2.5, which

has adverse effects on human health and ecosystems.BC has a strong warming effect both in the atmosphere and on

ice and snow.

CCAC (2014)

As a warming agent:Absorbing solar radiation and

converting it to heat Increasing the melting rate of

ice and snow

As an air pollutant:Leading environmental cause

of poor health and premature death such as cardiovascular mortality.

Affecting ecosystem health.

BC emissions

Comparison between anthropogenic and

open biomass burning emissions in SE Asia

Residential combustion is major emissions source in East Asia.Contribution from industry sector (coal combustion, production

of cokes and bricks, etc.) is also large in China.Majority of emissions in transport sector is from diesel vehicles.Open biomass burning is important especially in Southeast Asia.

[Tg/year]

Global(GAINS)in 2005

China(REAS 2.1)in 2008

SE Asia(REAS 2.1)in 2008

Sector share ofanthropogenic emissions*

in Global total, China,and SE Asia

Trends of anthropogenic

emissionsin China and

SE Asia(REAS 2.1)

[Tg/year]

* Open biomass burning emissions are not included in these graphs.

Methane (CH4)CH4 is over 20 times more potent than CO2 as GHGs.CH4 has indirect impacts on human health and ecosystems

through its role as the primary precursor of tropospheric O3.

Major emission sources are agriculture, fossil fuel production and distribution, and waste treatment.

In China, coal mining is the largest source.Oil and gas production and distribution as well as agricultural

activities are estimated to be important emissions source in SE Asia.

China(REAS 2.1)

Southeast Asia(REAS 2.1)

F_ = Fugitive emissions

Global (EDGARv4.2)

Sector share of anthropogenic emissions of Global total, China, and SE Asia in 2008

Hydrofluorocarbons (HFCs)HFCs are man-made fluorinated GHGs.There is no impact on human health and ecosystem.HFC-134a has 1430 times more damaging influence on the

climate system than CO2.

China 70%Japan 25%

HFCs emissionsin 2008

EDGARv4.2

Global Consumption

by sector in 2010CCAC (2014)

HFCs currently represent only a small fraction of the total GHGs, but emissions of high-global warming potential (GWP) HFCs are rising very quickly.

A recent study concluded that replacing high-GWP with low-GWP alternatives could avoid 0.1 of warming by 2050.℃

Tropospheric Ozone (O3)O3 is a secondary gas (not directly emitted).Tropospheric O3 is formed by sunlight-driven oxidation of

precursor gases (CH4, CO, NMVOCs, and NOx).Tropospheric O3 is the 3rd most important contributor to the

human enhancement of the GHGs effects. Tropospheric O3 is a harmful air pollutant adversely affecting

public and ecosystem health.O3 can make a transboundary air pollution problem.

Differences as O3 precursors:CH4 and CO is important for tropospheric O3 in global scale.NOx and NMVOCs is more effective for high surface O3.

CCAC (2014)

Adverse impacts of O3

Regional and urban ozone pollution in East Asia is more serious than in Europe and North America.

Social incentives for controlling air pollution of O3 as well as PM2.5 are expected to be stronger in East Asia.

Regional ratios of respiratory mortality (persons) related to O3 in 2005

(Lelieveld et al., ACP, 2013)

CCAC (2014)

Majority of mortality related to O3 is clearly in Asian region, especially China and India.

Reduction of CH4 is effective for long-term decrease of tropospheric (global) O3.

For immediate reduction of urban/regional surface O3, controlling NOx/NMVOCs is needed.

Both of NOx/NMVOC and CH4 reduction are important and should be considered in East Asia especially in heavily polluted areas.

Tropospheric O3 and Surface O3

-20% NOx-20% CH4-20% NOx/NMVOCs/CO

Only reduction of NOx will lead to increase of CH4, which increase net radiative forcing.

However, if NMVOCs and CO are reduced at the same time with NOx, O3 will be decreased without increase of net radiative forcing.

(Fry et al., JGR, 2012)

EA: East Asia, EU: Europe and North AfricaNA: North America, SA: South Asia

Effects of reducing anthropogenic EMs on Radiative forcing

Warming

Cooling

NOx and NMVOCs emissionsSector share of NOx emissions in 2008

For China, majority NOx emissions is from power plants, and those from industry and transport are comparable. Road transport is major emission source in Southeast Asia.

NMVOCs emissions from road vehicles and solvent and paint use have large contributions in China. Contributions from road vehicles as well as biofuel combustion are large in Southeast Asia.

Global (EDGARv4.2)

China(REAS 2.1)

Southeast Asia(REAS 2.1)

Global (EDGARv4.2)

China(REAS 2.1)

Southeast Asia(REAS 2.1)

Sector share of NMVOCs emissions in 2008

Benefits in the case if control measures are implemented globally by 2030

For NE/SE Asia and Pacific

Climate Avoided warming up to 0.05 in 2050℃ Reduced disruption of weather patterns Reduced rate of melting and sea-level rise

Avoided warming will be twice of that in NA and Europe.

Public Health

Avoided annual deaths of 2.4 mil. from outdoor air pollution by 2030

Additional benefits from reduced indoor pollution

37% of global benefits in 2030

Agriculture Avoided annual loss of 52 mil. tonnes of crop yields per year by 2030

28% of global benefits in 2030

Benefits of Mitigating SLCPsUNEP and WMO (2011) identified 16 cost effective SLCPs control measures such as for cook stoves, diesel vehicles, coal mines, municipal waste, etc.

CCAC (2014)

SummaryFor near-term mitigation of climate change, reduction of SLCPs

that have relatively short lifetime in the atmosphere and have warming influence on climate such as BC, CH4, HFCs, and O3 is essential.

SLCPs have adverse impacts on human health and ecosystem including agriculture (food security) as well as climate change.

Emissions of SLCPs in East Asia covering Northeast and Southeast Asia have already exceeded or at least been comparable to those in European and North American continent.

Social incentives for controlling air pollution of O3 as well as PM2.5 are expected to be stronger in East Asia.

In East Asia, both of NOx/NMVOC and CH4 reduction are important and should be considered especially in heavily polluted area.

Benefits of SLCP control measures for East Asia are estimated to be larger than other regions.

Thank you for your attention!

Thank you for your attention!

CCAC (2014)

CCAC (2014)