LETTERS

Personal carbon trading: ian individual is about 17 metric tons,4 1 Egger G. Personal carbon trading: a potential including energy usage. As the biomass of “stealth intervention” for obesity reduction. Med J a potential “stealth Aust 2007; 187: 185-187. trees in a mature forest sequesters about 6 2 Chisholm A. Carbon taxation: an evaluation of intervention” for obesity 4 2 metric tons of CO2 per hectare (10 m ) per options and outcomes. Australian Government reduction? year,4,5 each child born should be offset by Department of the Environment and Water Resources, Mar 1996. http://www.environ- Barry N J Walters planting 4 hectares of trees, to allow for the ment.gov.au/about/publications/economics/taxa- time they take to reach maturity, and attri- tion/carbon.html (accessed Oct 2007). TO THE EDITOR: Egger makes novel and tion through crop losses, bushfires, dieback 3 Sustainable Population Australia. How can you lower the birth rate? http://www.population.org.au/ valid points in his portrayal of individual and so on. This infers a levy per child of at whatyoucando/helplowerthebirthrate.htm human effort as a potential contributor to least $5000 at birth (to purchase the land (accessed Oct 2007). offsetting emissions by per- needed and plant trees) and an annual tax of 4 Cline WR. The economics of global warming. Wash- 1 $400–$800 thereafter for the life of the child ington, DC: Peterson Institute for International Eco- sonal carbon trading. Of course, there is an nomics, 1992: 221-222. even more potent strategy humans should (for maintenance of the afforestation 5 Ward P. Cool Antarctica. Carbon offsetting — tree adopt to modify through project) (based on 1990 figures,4 and proba- planting. http://www.coolantarctica.com/Antarctica% their own activities — population control. bly much more now). 20fact%20file/science/carbon_offsetting_tree_ planting.htm (accessed Oct 2007). Anthropogenic greenhouse gases consti- By the same reasoning, contraceptives, 6 Attenborough D. The life of mammals [television tute the largest source of pollution, with by intrauterine devices, diaphragms, condoms broadcast]. BBC television, 2002. Quoted by: Atten- far the greatest contribution from humans in and sterilisation procedures should attract borough D. Letter to Professor John Guillebaud. The The Medical Journal of Australia ISSN: 0025-729Xcarbon credits for the user and the pre- environment time capsule. http://www.ecotimecap- the developed world. Every newborn baby sule.com/attenborough.html (accessed Nov 2007). ❏ in Australia3/17 December represents 2007 a 187potent 11/12 source 668-668 of scriber that would offset their income taxes, greenhouse©The gasMedical emissions Journal for an averageof Australia of and 2007 lead to rewards for family planning www.mja.com.au 80 years,Letters not simply by breathing, but by clinics and hospitals that provide such the profligate consumption of resources typ- greenhouse-friendly services. Garry Egger ical of our society. As David Attenborough said: What then should we do as environmen- . . . instead of controlling the environ- IN REPLY: I agree with Walters. One must tally responsible medical practitioners? We ment for the benefit of the population, wonder why population control, which was should point out the consequences to all we should control the population to such a popular topic during the 1970s, is who fail to see them, including, if necessary, ensure the survival of the environment.6 spoken of today only in whispers. Is this because of the discovery of new oil in the the ministers for health. Far from showering As doctors, I believe we need to think this 1980s, taking resource scarcity off the pub- financial booty on new mothers and thereby way. Our responsibility extends further than lic agenda? Is it because of politicians and rewarding greenhouse-unfriendly behav- the patient on the other side of the desk. As economists, so keen on the growth trail that iour, a “Baby Levy” in the form of a carbon Australians, I believe we need to be less “. . . one for mum, one for dad and one for tax should apply, in line with the “polluter arrogant. As citizens of this world, I believe 2 the country”1 seems an easy solution? Or is pays” principle. Every family choosing to we deserve no more population concessions it the great religions, intent on outnumber- have more than a defined number of chil- than those in India and China. dren (Sustainable Population Australia sug- ing each other? Barry N J Walters, Clinical Associate Professor gests a maximum of two3) should be Environmental groups have also gone of Obstetric Medicine silent on the issue — perhaps afraid to charged a that would fund the Department of Women’s and Infants’ Health, planting of enough trees to offset the carbon University of Western Australia, King Edward alienate their growing support on other cost generated by a new human being. The Memorial Hospital, Perth, WA. environmental issues. Population remains crucial to all environ- average annual CO2 emission by an Austral- [email protected] mental (and subsequently, health) consider- ations. The debate needs to be reopened as part of a second ecological revolution (fol- lowing the failure of the first in the 1960s and 1970s).2 Doctors, as opinion leaders in the community, must be at the forefront of this debate.

Garry Egger, Director1 and Adjunct Professor of Health Sciences2 1 Centre for Health Promotion and Research, Sydney, NSW. 2 Southern Cross University, Lismore, NSW. [email protected]

1 Costello P. Treasurer of the Commonwealth of Aus- tralia. Interview with radio station 6PR [transcript of interview]. 22 Sep 2006. http://www.treas- urer.gov.au/tsr/content/transcripts/2006/ 133.asp?pf=1 (accessed Oct 2007). 2 Meadows DH, Randers J, Meadows DL. Limits to growth: the 30-year update. White River Junction, Vt: Chelsea Green Publishing, 2004. ❏

668 MJA • Volume 187 Number 11/12 • 3/17 December 2007