Climate Change and HFCs

a very brief scientific introduction

Archie McCulloch

Greenhouse Gases (Kyoto)Carbon dioxide - CO2

Methane - CH4

Nitrous oxide - N2OThe F-gases:

HFC - hydrofluorocarbonPFC - perfluorocarbonSF6 - sulphur hexafluoride

Greenhouse Gases (Kyoto)Carbon dioxide - CO2

Methane - CH4

Nitrous oxide - N2OThe F-gases:

HFC - hydrofluorocarbonPFC - perfluorocarbonSF6 - sulphur hexafluoride

Montreal Protocol Gases

CFC - chlorofluorocarbonHCFC - hydrochlorofluorocarbon

CFCs and HCFCs

Deplete stratosphericozone

Are also Greenhouse Gases

CFCs and HCFCs

Deplete stratosphericozone

Are Greenhouse Gases

stratosphere 40 km

25 km

15 km

CFCs and HCFCs

Deplete stratosphericozone

Are Greenhouse Gases

Production andConsumption are controlled by the Montreal Protocol.Emissions are not controlled.

Stratospheric Ozone Depletion and Climate Change can beaddressed separately, even though they have scientificinterconnections.

stratosphere 40 km

25 km

15 km

HFCs

Do not depletestratospheric ozone

Are Greenhouse Gases troposphere

40 km

25 km

15 km

HFCs

Do not depletestratospheric ozone

Are Greenhouse Gases

Emissions are controlledunder the Kyoto Protocol.

Other Kyoto Greenhouse Gases are:Carbon dioxide (CO2), methane, nitrous oxide, perfluorocarbonssulphur hexafluoride (SF6) - all controlled;Ozone, hydrocarbons - not controlled.

troposphere

40 km

25 km

15 km

The Environmental Impact ofany substance depends on

The Quantity of the Substance EMITTED

and

The Properties of the Substance

These Window air conditioners will affect climate change by EMISSION of greenhouse gases.

They consume electricity, which is generated from fossil fuel combustion and so results in EMISSION of CO2

They consume electricity, which is generated from fossil fuel combustion and so results in EMISSION of CO2

During normal operation there is NO EMISSION of the operating fluid.

They consume electricity, which is generated from fossil fuel combustion and so results in EMISSION of CO2

During normal operation there is NO EMISSION of the operating fluid. When the units are serviced or scrapped the fluid may be emitted.

Their Environmental Impact depends on

The quantity of electricity used (which has implications for energy efficiency) and

The amount of operating fluid emitted, and its Global Warming Potential(GWP).

Greenhouse gases

absorb infra-red radiation and hence can affect the climatefor as long as they persist in the atmosphere.

0

0.5

1

1.5

2

2.5

3

0 100 200 300 400 500

Time after emission (years)

Ab

so

lute

Glo

ba

l W

arm

ing

P

ote

nti

al

(Wm

-2yr

pp

m-1

)

CO2

Greenhouse gases

absorb infra-red radiation and hence can affect the climatefor as long as they persist in the atmosphere.

Global Warming Potential (GWP)

is a measure over a fixed time period of the effect of anemission of ONE kilogram of the greenhouse gascompared to the effect from ONE kilogram of carbondioxide over the same period.

It takes account of the absorption effectiveness of the gasand its persistence. The persistence of CO2 is ignored.

Global WarmingPotentials

(up to 100 years)

CO2

MethaneNitrous Oxide

HFC-152aHFC-134aHFC-125

Fluoroform

PFC-14

SF6

1

21310

14013002800

11700

6500

23900

On their own,these numbersdo not describethe impact ofthe gases.

Global WarmingPotentials

(up to 100 years)

CO2

MethaneNitrous Oxide

HFC-152aHFC-134aHFC-125

Fluoroform

PFC-14

SF6

Emission during2000 (tonnes)

1

21310

14013002800

11700

6500

23900

30,800,000,000

350,000,00011,000,000

100,000

7,000

15,000

6,000

Projected Climate Forcing, using "Best Estimate" Scenarios

0

1

2

3

4

5

6

1990 2010 2030 2050 2070 2090 Year

Ra

dia

tiv

e F

orc

ing

sin

ce

17

65

, W

m-2

Carbon Dioxide

Methane

Nitrous oxideODS

ODS areOzone Depleting Substancescontrolled under the Montreal Protocol

PFCs

HFCs

SF6

Trends in Production of HFC-134a

0

20

40

60

80

100

120

140

160

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

Year

Pro

du

ctio

n k

t/yr

Actual Production

Projected Climate Forcing, using "Best Estimate" Scenarios

0

1

2

3

4

5

6

1990 2010 2030 2050 2070 2090 Year

Ra

dia

tiv

e F

orc

ing

sin

ce

17

65

, W

m-2

With thanks to:

AFEAS (Alternative Fluorocarbons EnvironmentalAcceptability Study)

for emission and production data

IPCC(Intergovernmental Panel on ClimateChange)

for Global Warming Potentialsand Greenhouse Gasemission data

University of East Anglia for theClimate Model