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Characterisation Method Information
Characterisation Method Name:
CO2 impact on YOLL
Date Completed:
Principal Method Name:
EPS: heat stress, starvation, flooding accidents and malaria
Method Description:
YOLL stands for Year of Lost Life.

Model 1, pathway via heat stress

The characterisation factor is determined by an empirical method.

Using the assumption of an average shortening of life expectancy of 0.3 year, a temperature increase of 1.5 degrees, the total life shortening on a global basis will be 5.9 million YOLL per year as an average during 100 years.

For the ICPP (Intergovernmental Panel on Climate Change) scenario IS92A it is 14 Gton C as an average during the next 100-year period. This means that one kg CO2 contributes with 1.26E-16 to the total greenhouse effect during 100 years.

The characterisation factor will thus be 5.9E+06 *100* 1.26E16 = 7.43E-08 YOLL/kg CO2.

Model 2, pathway via starvation

The characterisation factor is determined by an empirical method.

The increase of mortality due to starvation caused by global warming is estimated below in two ways. The first is by using the estimation of the increased number of starving people and assume that the death cause among those people is mainly due to starvation (50%) and that the average life expectancy is reduced to 50 years. With Parry's figures on the increase of the starving population (Parry 1994) this would give 600 000 - 3.5 million cases per year, and a best estimate of 1.8 million cases per year. The other way of estimating the excess mortality is by using the death frequency figures from Guatemala and Mexico on the poorest 1 billion of the earth's population and assume that the 5% decrease of world crop production estimated by Krol (1993) will occur amongst them. This will roughly mean a 25% decrease of food production in the poor regions and should result in more than a 25% increase of the death rates in classes AM 22 and AM 23. A 25% increase, using the average figures for Guatemala and Mexico (3.4%) would mean 0.85% of 1,000,000,000/50, which is 170,000 cases per year. Other death causes, particularly from infectious diseases are also influenced by the nutrition status of the population.

Based on these considerations and applying the recautionary principle the figure 1.8 million cases per year will be used as a default value. No information is at present available about the average shortening of life expectancy due to excess mortality, but the general impression from media reporting from areas where starvation occur is that it strikes at all ages. An average shortening of life of 30 years is therefore assumed resulting in 54 million YOLL per year or 5.410 9 YOLL per 100 year.

Then the characterisation factor of this pathway is

5.410 9 *1.2610 16 = 6.810 7 YOLL/kg CO2

Model 3, pathway via flooding accidents

The characterisation factor is determined by an empirical method.

IPCC considers it likely that the global warming causes the increased frequency of natural disasters in terms of flooding and cyclones. In that case the number of victims would at most be around 15,000 per year for the period. Compared to other effects by CO2, this is small and for the purpose of this work and applying the precautionary principle it may be relevant to use this value.

Assuming excess mortality striking randomly at persons of different age, the average reduction of life expectancy will in the range of 30 years corresponding to 450000 YOLL per year or 4.510 7 YOLL per 100 years.

Then specific characterisation factor in this pathway is

4.510 7 *1.2610 16 = 5.710 9 YOLL/kg CO2

Model 4, pathway via malaria

The characterisation factor is determined by an empirical method.

IPCC working group II reports on models indicating that the geographical zone of potential malaria transmission in response to world temperature increase at the upper part of IPCC projected range (3-5 o C by 2100) will increase. The increase would be from 45% of the world population at risk to approximately 60%. The model estimates the potential increase of malaria incidence to 50-80 million cases compared to the global background of 300 - 500 million cases. This means an increase about 10%.

The global average mortality rate relative to the incidence is today 0.5%, but the figure varies in different countries and regions, and a conservative estimate of half the average mortality is made. The total indicator value in the system considered will therefore be 2.610 8 YOLL per hundred years.

The specific characterisation factor in this pathway is then
2.6E+08 *1.26E16 = 3.3E8 YOLL/kg CO2

Calculation of characterisation factor

Considering all pathways, the characterisation factor for CO2 with respect to YOLL is
7.43E-08 + 6.8E07 + 5.7E09 + 3.3E08 = 7.93E07 YOLL/kg CO2
Literature Reference:
1. Houghton, J.T Jenkins, G.J. and Ephraums, J.J., (Ed.) (1990) Climate change The IPCC scientific assessment. Cambridge University Press 2. Weihe in "Urban Climatology and its Applications with Special Regard to Tropical Areas". Proceedings of the technical conference, Mexico D.F, 26-30 November 1984, WMO-report No. 652, Geneva 1986 3. Parry, Martin. International climate conference at Maastricht, dec 8, 1994, (1994) 4. WHO, World health report, 1997
Methodological Range:
The flow group and its impacts are of global character. The modelled system is therefore global. The temporal system borders are 100 years (1990-2090). The society affected is the one described in IPCC scenario IS92A. (IPCC, 1990)

Existing Characterisation Factors of CO2 impact on YOLL
Characterisation Parameter Category Indicator Impact Indication Principle Aspect Substance Quantity Unit Notes
CFactor YOLL EPS/2000
Type = Emission
Direction = Output
Media = Air
Geography = *
CO2 7.93E-07 p yr/kg 4 pathways