The Carbon Cycle - Policy Nexus

Robert T. WatsonIPCC, Chair

COP-6bisBonn, Germany

July 17th

Global Carbon Cycle Key Messages

Human activities (combustion of fossil fuels and land-use changes) have and are continuing to perturb the carbon cycle -- increasing the atmospheric concentration of carbon dioxide

The terrestrial biosphere has historically been a source of carbon to the atmosphere - it is currently a net sink

The current terrestrial carbon sink is caused by land management practices, higher carbon dioxide, nitrogen deposition and possibly recent changes in climate

This uptake by the terrestrial biosphere will not continue indefinitely. The question is when will this slow down, stop or even become a source?

LULUCF activities will result in the sequestration of carbon in three main pools -- above and below ground biomass and soils for decades to centuries

Global Carbon Cycle Key Messages

some of the LULUCF sequestered carbon could be released back to the atmosphere due to changes in climate, but unlikely for many decades -- even then there would still be more carbon in the three pools than without the LULUCF activities

there may be a few instances, e.g., Boreal forests at high latitudes, when the benefits of carbon sequestration may be partially or fully offset by changes in albedo

slowing deforestation has multiple environmental and social benefits

monitoring systems can be put in place to monitor all three pools of carbon

LULUCF activities buy time to transform energy systems to lower GHG emitting systems, but will allow more fossil carbon to transferred to the more labile biological pools, hence avoiding a tonne of carbon emissions is better than creating a tonne of sinks

Indicators of the Human Influenceon the Atmosphere during the Industrial Era

Carbon emissions and uptakes since 1800 (Gt C)

180

110

115

265

140Land use change

Fossil emissions

Atmosphere

Oceans

Terrestrial

The Global Carbon Cycle - 1990sUnits Gt C and Gt C y-1

The KP seeks to reduce net carbon emissions by about 0.3 Gt C below 1990 levels from industrial countries

Atmosphere

Fossil Deposits6.3

63

91.7

60

90

3.2

Plants

Soil

Oceans

750

500

2000

39,000

About 16,0001.

6

…are leading to a build up of CO2

in the atmosphere.

Fossil emissions ...

…and land clearing in the tropics...

Current Role of the Terrestrial Biosphere

During the 1990s the net global uptake of carbon by the terrestrial biosphere was about 1.4 Gt C per year --- assuming emissions from tropical deforestation in the 1990s were about 1.6 Gt C per year (the same as in the 1980s) --then the gross uptake of carbon by the terrestrial biosphere was about 3 Gt C per year

Inverse modeling suggests that about 50% of the global uptake is occurring in the tropics and the other 50% in the mid- and high-latitudes of the northern hemisphere

The primary cause of the current uptake (about 1.5 Gt C per year) in N. America, Europe and Asia is, as said earlier, thought to be re-growth due to management practices, with carbon dioxide, nitrogen fertilization and climate change contributing, but to smaller extent

1900 1950 2000 2050 2100

Net

eco

syst

em p

rodu

ctiv

ity,

Gt

C y

r –1

Sink

Source

4

2

0

–2

Predicted effects of changes in climate and atmospheric CO2 on the global net uptake of carbon by terrestrial ecosystems -- this model shows the sink maximizing in about 2050 and declining to zero by 2100 -- other models tend to show constant or less of a decline after 2050

Global Net Ecosystem Productivity

The Kyoto ProtocolThe Challenge of Mitigation

The near-term challenge is to achieve the Kyoto targets

The longer-term challenge is to meet the objectives of Article 2 of the UNFCCC, i.e., stabilization of GHG concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system food security ecological systems and sustainable economic development

The Long-term ChallengeCarbon emissions and stabilization scenarios

The Challenge of Stabilization of Atmospheric Concentrations of Carbon Dioxide

If governments decide to stabilize the atmospheric concentration of carbon dioxide at 550ppm (about twice the pre-industrial level), global emissions would have to peak by about 2025 and fall below current levels by 2040 to 2070.

This would mean that all regions would have to deviate from most “business-as-usual”scenarios within a few decades

Key Conclusions of IPCC In the absence of trading, Annex B costs of complying

with the Kyoto Protocol, range from $150-600/tC (i.e., 0.2 - 2% loss of GDP), where-as with full Annex B trading the costs are reduced to $15-150/tC (i.e., 0.1 - 1% loss of GDP)

These costs could further reduced with use of: the Clean Development Mechanism

sinks

mixture of greenhouse gases

ancillary benefits and

efficient tax recycling

If all cost reduction activities could be realized then GDP growth rates would only have slow by a few hundreds of a percent per year

Article 3.3 The net changes in greenhouse gas emissions from sources and removals by sinks resulting from direct human-induced land-use change and forestry activities, limited to afforestation, reforestation, and deforestation since 1990, measured as verifiable changes in stocks in each commitment period shall be used to meet the commitments in this Article of each Party included in Annex I. The greenhouse gas emissions from sources and removals by sinks associated with those activities shall be reported in a transparent and verifiable manner and reviewed in accordance with Articles 7 and 8.

Which stock changes? All, or only those directly human induced - what is included?

Can we separate the growth increment due to “normal” forest growth from that due to carbon dioxide, nitrogen fertilization and climate change or year-year climate variability? -- IPCC may be asked to assess this possibility

Key Issues for the Kyoto ProtocolArticle 3.3

Potential net emissions from forestsArt. 3.3 Annex 1 Countries

Mt C yr-1

AR DIPCC definitions 26 -90

Annex 1

Note the qualifications about these estimates.•Based on assumption that current rates of ARD continue through to 2012•Assumptions about the shape of the growth curve greatly affect the outcome

Potential emissions reductions from forests under CDM (using Art. 3.3 rules) in non-Annex 1 Countries

Mt C yr-1 AR DIPCC definitions 373 -1600

Non-Annex 1

Avoided deforestation not eligible under current Pronk text

- concern about baselines, leakage, permanence

- multiple benefits, including biodiversity, water resource management

Article 3.4 … Such a decision shall apply in the second and subsequent commitment periods. A Party may choose to apply such a decision on these additional human-induced activities for its first commitment period, provided that these activities have taken place since 1990.

The key issue is whether these activities must commence after 1990 or whether activities initiated before 1990, but that are continued after 1990, are eligible -- a key issue with respect to the current net terrestrial uptake -- Pronk text finesses this issue by discounting for the first commitment period

Contrasts with Article 3.3 refers to “direct human-induced activities

Key Issues for the Kyoto ProtocolArticle 3.4

Interpretations of Article 3.4

Narrow definitionNarrow definition

Broad definitionBroad definition

USA definitionUSA definition

Forest Management

Cropland Management

Grazing land Management

Full carbon accounting All stocks across all carbon pools If applied to all land in all countries then the

accounting would produce the “Net terrestrial uptake” of about 1.4 GtC y-1 (IPCC TAR) without any additional effort to reduce emissions or increase sinks

Assuming emissions from tropical deforestation are 1.6 GtC y-1, this suggests a global uptake of about 3 GtC y-1

Assuming 50% of the uptake is at mid- and high latitudes, this would allow Annex I Parties to claim an annual credit of between about 1.5 GtC y-1 due to the residual uptake because of improved management practices pre-1990, carbon dioxide and nitrogen fertilization effect and climate change. Current text would limit this credit by discounting by 85%.

The current text

discounts credits for forest management under Article 3.4 by

85%, and

limits the use of sinks to 50% of total

reductions

Maximum USA & Japan purchases

0

10

20

30

40

50

60

70% 75% 80% 85% 90% 95% 100%

Forest mgmt discount (Pronk = 85%)

Mt C

/ yr

0

10

20

30

40

50

60

20% 30% 40% 50% 60% 70% 80%

Cap on the use of sinks (Pronk 50%)

Mt C

/ yr

Accounts for pre-1990 activities, does not separate direct from indirect human activities, and accepts broad definitions

I

0 0.1 0.2 0.3

Forest management

Cropland management

Grazing land management

Agroforestry

Rice Paddies

Urban land management Annex 1 Global

Contains a best estimate of the rate of uptake of these activities by 2010 (varies between 3% to 80%) -- current text would inhibit investment in forest management under Article 3.4 because of the 85% discounting

Annual C sequestration potential (GtC/y) improvement of management within cover type -

new activities since 1990

Annual C sequestration potential (GtC/y)Transformation between cover types

0 0.1 0.2 0.3 0.4 0.5

Cropland to grassland

Degraded agriculture to agroforest

Wetland restoration

Degraded land restoration Annex 1 Global

Annual C sequestration potential (GtC/y) - change in cover type - new activities since 1990

Can the Direct and Indirect Human-induced sequestration be separated??

“For activities that involve land-use changes (e.g., from grassland/pasture to forest) it may be very difficult, if not impossible, to distinguish with present scientific tools that portion of the observed stock change that is directly human-induced from that portion that is caused by indirect and natural factors.”

Emissions and removals from natural causes such as El Niño may be large compared with commitments - year to year natural global carbon uptake varies by as much as 2-4 Gt C per year - terrestrial systems do not sequester efficiently during El-Nino events - the climate is predicted to become more El-Nino-like

For activities that involve land-management changes (e.g., tillage to no-till agriculture), it should be feasible to distinguish between the direct and indirect human-induced components through control plots and modeling, but not to separate out natural factors

Permanence “Sinks” are potentially reversible

through human activities, disturbances, or environmental change, including climate change.

This is a more critical issue than for activities in other sectors, e.g., the energy sector.

A pragmatic solution … ensure that any credit for enhanced carbon stocks is balanced by accounting for any subsequent reductions in those carbon stocks, regardless of the cause.

Monitoring Carbon Technical methods sufficient to serve the requirements of

the Protocol exist for above ground stocks and most likely for below ground stocks.

Annex 1 Parties generally have the technologies available, but few currently apply them routinely for monitoring

Non Annex 1 Parties may require assistance to develop the necessary capacities and cover costs

Methods and research results are highly transferable between Parties, and rapid improvement should be expected

Conclusion

LULUCF activities can play a critical role in limiting the build-up of carbon dioxide in the atmosphere, especially in the near-term, but to stabilize the atmospheric concentration of carbon dioxide (Article 2 of the Convention) will require significant emissions reductions globally, which can only be achieved by either reducing energy emissions or by capture and storage of energy emissions