Short Background on Climate Change and Greenhouse Gases

Dr Ruth NussbaumProForest

Presentation to the RSPO GHG WG2 meeting in Feb 2010

The Greenhouse Effect

Source: GLECOSYS

Solar radiation enters the atmosphere

The earth’s surface is warmed and radiates heat back into the atmosphere

Some energy is radiated into space, the rest is trapped as heat in the atmosphere – GHGs increase the amount of energy trapped

Main Greenhouse Gases

Carbon dioxide (CO2)•Stays in atmosphere: 1-2 yrs (uncertain)

•Global warming potential: 1 (all other gases GWP relative to CO2)

Methane (CH4)•Stays in atmosphere: 12±3 yrs

•Global warming potential: 23 (IPCC)

•1 tonne CH4 = 23 t CO2e

Nitrous Oxide (N2O)•Stays in atmosphere: 114 yrs

•Global warming potential: 296 (IPCC)

•1 tonne N2O = 296 t CO2e

Converting C to CO2e

• Carbon converted to CO2-equivalent (CO2e) using molar weights– Carbon (C)= 12– CO2 = 12+16+16 = 44– Conversion factor (CF) = 44/12 = 3.67– CO2e = tonnes of C * CF

• Biomass conversion to CO2e– Trees approximately 50% C– CO2e = tonnes of biomass * 0.5 * 3.67

Source: IPCC 2007

GHG Concentrations

Rad

iati

ve F

orc

ing

(W

/m2)

Atm

osp

heri

c

Con

cen

trati

on

Annual Global Sources and Sinks of GHGs

Sources

Fossil Fuels

Deforestation

6.4 Gt 1.6 Gt

Figures taken from Global Carbon Project and are indicative only Gt = giga tonne = 1 billion tonnes

+ =

Sinks

Atmosphere

3.1 Gt

Uncertain where this CO2 is going: assumed to be a land sink (e.g. regenerating forest)

Oceans

2.2 Gt+ 2.6 Gt+

These values are in addition to background naturally occurring sources and sinks

For 1990-2000For 2000-2008

7.7 1.4 4.1 3.0 Gt2.3 Gt

Taken up by “land”, with a 0.3 Gt residual unaccounted for

Current Temperature Rise

Projected Fossil Fuel Emissions: Actual vs. IPCC Scenarios

Source: Global Carbon Project [Raupach et al. 2007, PNAS, updated; Le Quéré et al. 2009, Nature Geoscience; International Monetary Fund 2009]

1990 1995 2000 2005 2010 2015

Fo

ssil

Fu

el E

mis

sio

n (G

tC y

-1)

5

6

7

8

9

10

Projection

A1B

A1FI

A1T

A2

B1

B2

Carbon Dioxide Information Analysis Center

International Energy AgencyProjection 2009Emissions: -2.8%GDP: -1.1% C intensity: -1.7%

Due to Global Recession

Projected Temperature Rise

2 C is the maximum

temperature rise the UNFCCC

“recommends”

Our current trajectory is closer to 4 C

Projected Changes in Precipitation

Consistent findings across scenarios

Increased Asian Monsoon