Transcript Climate Change and HFCs a very brief scientific introduction

Climate Change and HFCs
a very brief scientific introduction
Archie McCulloch
Greenhouse Gases (Kyoto)
Carbon dioxide - CO2
Methane - CH4
Nitrous oxide - N2O
The F-gases:
HFC - hydrofluorocarbon
PFC - perfluorocarbon
SF6 - sulphur hexafluoride
Greenhouse Gases (Kyoto)
Carbon dioxide - CO2
Methane - CH4
Nitrous oxide - N2O
The F-gases:
HFC - hydrofluorocarbon
PFC - perfluorocarbon
SF6 - sulphur hexafluoride
Montreal Protocol Gases
CFC - chlorofluorocarbon
HCFC - hydrochlorofluorocarbon
CFCs and HCFCs
Deplete stratospheric
ozone
Are also Greenhouse Gases
CFCs and HCFCs
Deplete stratospheric
ozone
stratosphere
40 km
25 km
Are Greenhouse Gases
15 km
CFCs and HCFCs
Deplete stratospheric
ozone
stratosphere
40 km
25 km
Are Greenhouse Gases
15 km
Production and
Consumption are controlled
by the Montreal Protocol.
Emissions are not controlled.
Stratospheric Ozone Depletion and Climate Change can be
addressed separately, even though they have scientific
interconnections.
HFCs
Do not deplete
stratospheric ozone
40 km
25 km
Are Greenhouse Gases
troposphere
15 km
HFCs
Do not deplete
stratospheric ozone
40 km
25 km
Are Greenhouse Gases
troposphere
15 km
Emissions are controlled
under the Kyoto Protocol.
Other Kyoto Greenhouse Gases are:
Carbon dioxide (CO2), methane, nitrous oxide, perfluorocarbons
sulphur hexafluoride (SF6) - all controlled;
Ozone, hydrocarbons - not controlled.
The Environmental Impact of
any 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 climate
for as long as they persist in the atmosphere.
Absolute Global Warming
Potential
(Wm-2yrppm-1)
3
2.5
CO2
2
1.5
1
0.5
0
0
100
200
300
Time after emission (years)
400
500
Greenhouse gases
absorb infra-red radiation and hence can affect the climate
for as long as they persist in the atmosphere.
Global Warming Potential (GWP)
is a measure over a fixed time period of the effect of an
emission of ONE kilogram of the greenhouse gas
compared to the effect from ONE kilogram of carbon
dioxide over the same period.
It takes account of the absorption effectiveness of the gas
and its persistence. The persistence of CO2 is ignored.
Global Warming
Potentials
(up to 100 years)
CO2
Methane
Nitrous Oxide
HFC-152a
HFC-134a
HFC-125
Fluoroform
PFC-14
SF6
1
21
310
140
1300
2800
11700
6500
23900
On their own,
these numbers
do not describe
the impact of
the gases.
Global Warming
Potentials
(up to 100 years)
CO2
Methane
Nitrous Oxide
HFC-152a
HFC-134a
HFC-125
Fluoroform
PFC-14
SF6
Emission during
2000 (tonnes)
1
30,800,000,000
21
310
350,000,000
11,000,000
140
1300
2800
100,000
11700
7,000
6500
15,000
23900
6,000
6
Radiative Forcing since 1765, Wm-2
5
Projected Climate Forcing,
using "Best Estimate"
Scenarios
4
3
Carbon Dioxide
2
Methane
1
ODS are
Ozone Depleting Substances
controlled under the
0
Montreal Protocol
1990
SF
6
ODS
2010
2030
Nitrous oxide
PFCs
2050
HFCs
Year
2070
2090
Trends in Production of HFC-134a
160
140
Production kt/yr
120
Actual Production
100
80
60
40
20
0
1990
1991
1992
1993
1994
1995
Year
1996
1997
1998
1999
2000
6
With thanks to:
5
(Alternative Fluorocarbons Environmental
Acceptability Study)
for emission and production data
IPCC
(Intergovernmental Panel on Climate
Change)
for Global Warming Potentials
and Greenhouse Gas
emission data
University of East Anglia for the
Climate Model
Radiative Forcing since 1765, Wm-2
AFEAS
Projected Climate Forcing,
using "Best Estimate"
Scenarios
4
3
2
1
0
1990
2010
2030
2050
Year
2070
2090