Oregon State study says having fewer children is best way to reduce your carbon footprint
By Eric Mortenson, The Oregonian
July 31, 2009, 11:27AM
Some people who are serious about wanting to reduce their "carbon footprint" on the Earth have one choice available to them that may yield a large long-term benefit - have one less child.
A recent study by statisticians at Oregon State University concluded that in the United States, the carbon legacy and greenhouse gas impact of an extra child is almost 20 times more important than some of the other environmentally sensitive practices people might employ their entire lives - things like driving a high mileage car, recycling, or using energy-efficient appliances and light bulbs.
The research also makes it clear that potential carbon impacts vary dramatically across countries. The average long-term carbon impact of a child born in the U.S. - along with all of its descendants - is more than 160 times the impact of a child born in Bangladesh.
"In discussions about climate change, we tend to focus on the carbon emissions of an individual over his or her lifetime," said Paul Murtaugh, an OSU professor of statistics. "Those are important issues and it's essential that they should be considered. But an added challenge facing us is continuing population growth and increasing global consumption of resources."
In this debate, very little attention has been given to the overwhelming importance of reproductive choice, Murtaugh said. When an individual produces a child - and that child potentially produces more descendants in the future - the effect on the environment can be many times the impact produced by a person during their lifetime.
Under current conditions in the U.S., for instance, each child ultimately adds about 9,441 metric tons of carbon dioxide to the carbon legacy of an average parent - about 5.7 times the lifetime emissions for which, on average, a person is responsible.
And even though some developing nations have much higher populations and rates of population growth than the U.S., their overall impact on the global equation is often reduced by shorter life spans and less consumption. The long-term impact of a child born to a family in China is less than one fifth the impact of a child born in the U.S., the study found.
As the developing world increases both its population and consumption levels, this may change.
"China and India right now are steadily increasing their carbon emissions and industrial development, and other developing nations may also continue to increase as they seek higher standards of living," Murtaugh said.
The study examined several scenarios of changing emission rates, the most aggressive of which was an 85 percent reduction in global carbon emissions between now and 2100. But emissions in Africa, which includes 34 of the 50 least developed countries in the world, are already more than twice that level.
The researchers make it clear they are not advocating government controls or intervention on population issues, but say they simply want to make people aware of the environmental consequences of their reproductive choices.
"Many people are unaware of the power of exponential population growth," Murtaugh said. "Future growth amplifies the consequences of people's reproductive choices today, the same way that compound interest amplifies a bank balance."
Murtaugh noted that their calculations are relevant to other environmental impacts besides carbon emissions - for example, the consumption of fresh water, which many feel is already in short supply.
Anything is balance for the good and bad. So, The good thing for the big population in China is:
the big population is making the Chinese goes everywhere in the world, maybe take up the whole world finally.
7.13.2009 5:45 PM
How Rising Human Population Could Impact Global Warming
Dear EarthTalk: To what extent does human population growth impact global warming, and what can be done about it? -- Larry LeDoux, Honolulu, HI
No doubt human population growth is a major contributor to global warming, given that humans use fossil fuels to power their increasingly mechanized lifestyles. More people means more demand for oil, gas, coal and other fuels mined or drilled from below the Earth's surface that, when burned, spew enough carbon dioxide (CO2) into the atmosphere to trap warm air inside like a greenhouse.
According to the United Nations Population Fund, human population grew from 1.6 billion to 6.1 billion people during the course of the 20th century. (Think about it: It took all of time for population to reach 1.6 billion; then it shot to 6.1 billion over just 100 years.) During that time emissions of CO2, the leading greenhouse gas, grew 12-fold. And with worldwide population expected to surpass nine billion over the next 50 years, environmentalists and others are worried about the ability of the planet to withstand the added load of greenhouse gases entering the atmosphere and wreaking havoc on ecosystems down below.
Developed countries consume the lion's share of fossil fuels. The United States, for example, contains just five percent of world population, yet contributes a quarter of total CO2 output. But while population growth is stagnant or dropping in most developed countries (except for the U.S., due to immigration), it is rising rapidly in quickly industrializing developing nations. According to the United Nations Population Fund, fast-growing developing countries (like China and India) will contribute more than half of global CO2 emissions by 2050, leading some to wonder if all of the efforts being made to curb U.S. emissions will be erased by other countries' adoption of our long held over-consumptive ways.
"Population, global warming and consumption patterns are inextricably linked in their collective global environmental impact," reports the Global Population and Environment Program at the non-profit Sierra Club. "As developing countries' contribution to global emissions grows, population size and growth rates will become significant factors in magnifying the impacts of global warming."
According to the Worldwatch Institute, a nonprofit environmental think tank, the overriding challenges facing our global civilization are to curtail climate change and slow population growth. "Success on these two fronts would make other challenges, such as reversing the deforestation of Earth, stabilizing water tables, and protecting plant and animal diversity, much more manageable," reports the group. "If we cannot stabilize climate and we cannot stabilize population, there is not an ecosystem on Earth that we can save."
Many population experts believe the answer lies in improving the health of women and children in developing nations. By reducing poverty and infant mortality, increasing women's and girls' access to basic human rights (health care, education, economic opportunity), educating women about birth control options and ensuring access to voluntary family planning services, women will choose to limit family size.
March 13, 2009, 11:33 am
Scientist: Warming Could Cut Population to 1 Billion
By James Kanter
Lizette Kabré. Climate congress, Copenhagen 2009.
Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research, spoke several times at the climate conference in Copenhagen.[UPDATE, 1:45 p.m.: A roundup of economists' and scientists' views at the Copenhagen climate meeting and a reaction from Mike Hulme, a participating scientist.]
COPENHAGEN — A scientist known for his aggressive stance on climate policy made an apocalyptic prediction on Thursay.
Hans Joachim Schellnhuber, the director of the Potsdam Institute for Climate Impact Research in Germany, said that if the buildup of greenhouse gases and its consequences pushed global temperatures 9 degrees Fahrenheit higher than today — well below the upper temperature range that scientists project could occur from global warming — Earth’s population would be devastated. [UPDATED, 6:10 p.m: The preceding line was adjusted to reflect that Dr. Schellnhuber was not describing a worst-case warming projection. h/t to Joe Romm.]
“In a very cynical way, it’s a triumph for science because at last we have stabilized something –- namely the estimates for the carrying capacity of the planet, namely below 1 billion people,” said Dr. Schellnhuber, who has advised German Chancellor Angela Merkel on climate policy and is a visiting professor at Oxford.
At that temperature, there would be “no fluctuations anymore, we can be fairly sure,” said Dr. Schellnhuber, exercising his characteristically dark sense of humor at the morning plenary session on the closing day of an international climate change conference in Copenhagen, Denmark. [Earlier post: The conference organizers have sought to jog policymakers with a stronger assessment of global warming's risks, but some scientists warned the approach could backfire.]
“What a triumph,” Dr. Schellnhuber said. “On the other hand do we want this alternative? I think we can do much, much better,” he told the conference.
Dr. Schellnhuber, citing his own research, said that at certain “tipping points,” higher temperatures could cause areas of the ocean to become deoxygenated, resulting in what he calls “oxygen holes” between 600 and 2,400 feet deep. These are areas so depleted of the gas that they would badly disrupt the food chain.
Unabated warming would also lead to “disruption of the monsoon, collapse of the Amazon rain forest and the Greenland ice sheet will meltdown,” he said.
But on the bright side, he noted, in a joking reference to the meeting’s Danish hosts, the retreat of the sheath of ice covering Greenland, which is Danish-controlled territory, “would increase your usable land by, I don’t know, 10,000 percent.”
“But I’m not sure whether you want to do this,” he said.
World Population and Global Warming
L. David Roper
http://arts.bev.net/roperldavid
It is well established that carbon dioxide and the Earth’s average temperature form a mutual positive feedback system. (http://www.roperld.com/science/CO2_Temp.pdf)
This short paper is an attempt to quantify the amount of carbon dioxide emitted by humans breathing and to compare it to the emissions due to other human activities.
Carbon Dioxide Emissions by Breathing of Humans
Each day the average person breathes in about 15,000 liters, or approximately 35 pounds, of air. (http://www2.envmed.rochester.edu/envmed/TOX/faculty/frampton.html) Since air is 21% oxygen (molecular weight 16) and 78% nitrogen (molecular weight 14) by volume, oxygen is 23.5% by weight and nitrogen is 76.5% by weight in air. So the amount of oxygen breathed in per day by the average person is about 35*0.235 = 8.2 lbs.
Humans breath out about 16% oxygen by volume, so about 5% of the air by volume is converted to CO2, which is about (5/21)x8.2 = about 2 lbs of CO2 every day.
The molecular weight of O2 is 32 and the molecular weight of CO2 is 12+32=44. Therefore, humans emit 44x2x/32 lbs = about 2.8 lbs of CO2 breathed out every day or about 1005 lbs = about 0.5 tons per person per year.
In 2005 the Earth population was about 6.66x109. So the emitted CO2 per year by their breathing was about 3.3x109 tons. Most of that population is due to the using of fossil carbon compounds to farm (fuel and fertilizer). The fraction of fossil carbon compounds used to burn for energy in agricultural infrastructure can already be accounted for in the atmospheric CO2 by calculation from fossil fuel extraction.
In 2002 CO2 emissions due to human activities were about 25x109 tonnes = 27.6x109 tons (http://www.unep.org/geo/yearbook/yb2006/077.asp). Breathing comprises about 3.3x109 tons of that amount, or about 12% of it. It may be not all of the human breathing is accounted for in "emissions due to human activities"; some of the fossil fuel used to make food available may not be counted.
Globally, annual average emissions of carbon dioxide per capita due to human activities (other than breathing) have been fairly stable since 1990. For 2002, this figure was up to 3.93 tonnes from 3.85 tonnes in 2001 (http://www.unep.org/geo/yearbook/yb2006/077.asp). Per capita CO2 emissions for 2002 = 3.93 tonnes/person = 4.33 tons/person. Breathing adds about 12% more (0.5 tons per person per year)
This calculation just adds to the realization that the global-warming problem is, in essence, a population-explosion problem. Global warming may be one of nature’s ways to decrease human population.
For the long term the best way to reduce global warming is to reduce human population in a benign way by educating women and providing world-wide free contraception information and devices. If humans do not consciously do that, nature will do it due to the effects of global warming, the decline of petroleum extraction and the eventual entry into the next 115,000-year Major Ice Age. (See http://www.roperld.com/science/HumanFuture.pdf .)
The fossil-carbon compounds burned in agriculture are already accounted for in fossil-fuel burning calculations, assuming a certain % of the fossil-carbon being burned, the rest going into making useful compounds. Fossil-carbon compounds used for fuel and fertilizer and for food processing and transportation equipment, allow some carbon to be taken out of the soil, depleting the soil, which is difficult, if not impossible, to calculate. That is, some of the fossil carbon used to make agriculturally useful compounds should be counted as putting CO2 into the atmosphere.
It is obvious that the population explosion occurred because of the availability of fossil carbon fuels. Without coal, petroleum and natural gas the population would be much smaller. It probably is a good approximation to assume that the current population is largely due to the existence of fossil carbon.
“The overriding challenges facing our global civilization as the new century begins are to stabilize climate and stabilize population. Success on these two fronts would make other challenges, such as reversing the deforestation of Earth, stabilizing water tables, and protecting plant and animal diversity, much more manageable. If we cannot stabilize climate and we cannot stabilize population, there is not an ecosystem on Earth that we can save. Everything will change.”
— State of the World 2000, Worldwatch Institute
Global warming is one of the greatest threats ever to confront the precious but fragile ecosystems that make our Earth inhabitable. Global warming is not only altering wildlife habitat and changing the face of our planet, but it also poses a significant threat to human health and security. The rapid depletion of rain forests to meet the ever-increasing demand for forest products is just one example of how humans are irreversibly altering the Earth’s ecosystems.
In order to preserve the well-being of human and wildlife populations that depend on healthy, functioning ecosystems, we must address the root causes of this very real threat. Rapid and unchecked human population growth and the resulting increases in resource consumption lie at the heart of most, if not all, environmental problems. Global warming is no exception. The unprecedented increase in human numbers is paralleled by the highest levels of fossil fuel consumption and greenhouse gas production in history.
While industrial nations have been primarily responsible for high emissions levels in the recent past, the rapidly growing population of the developing world will be a major factor in future emissions levels. As we look to the developed world to curb and reduce emissions, many in developing countries need to increase their energy use to meet basic needs and improve their quality of life. Countries such as India and Brazil are looking for solutions to balance the needs of people and the planet. Therefore, all national policies and international agreements on global warming must take population growth into account.
With half of the current population either in or entering their reproductive years, the choices we make today will greatly impact the path that population takes in the future. Access to voluntary family planning and reproductive health care will dictate future fertility and mortality trends. How quickly the human population grows over the next fifty years will have a direct and significant impact on the extent of global warming and its social, economic, and environmental impacts.
第二天一早，同事一到办公室就找到我。
同事：我只想说非常感谢你。
我惊讶：怎么回事？
同事：我昨天晚上看了你传给我的那篇文章，毛的文章，《纪念白求恩》。 我没有想到，毛会写出这样的文章。
接着同事拿出打印的纸，大声朗读了起来：
“Comrade Bethune's spirit, his utter devotion to others without any thought of self, was shown in his great sense of responsibility in his work and his great warm-heartedness towards all comrades and the people。. Every Communist must learn from him. There are not a few people who are irresponsible in their work, preferring the light and shirking the heavy, passing the burdensome tasks on to others and choosing the easy ones for themselves. At every turn they think of themselves before others. When they make some small contribution, they swell with pride and brag about it for fear that others will not know. They feel no warmth towards comrades and the people but are cold, indifferent and apathetic.” 同事继续：“Now we are all commemorating him, which shows how profoundly his spirit inspires everyone. We must all learn the spirit of absolute selflessness from him. With this spirit everyone can be very useful to the people. A man's ability may be great or small, but if he has this spirit, he is already noble-minded and pure, a man of moral integrity and above vulgar interests, a man who is of value to the people. ”
读完后,同事对我说：“我很震惊。如果你不告诉我这是毛写的，如果我把里面所有共产主义或意识形态字眼去掉，如果有人在我面前朗读，我会以为我在聆听上帝宣讲。 毛说的这些，和我曾经在教堂听到过的几乎完全一样。”
同事伸出手来，“我真得非常感谢你。你让我看到了不一样的毛，我想我开始尊敬他了。 我更感谢的，我突然心变得很开阔了，我觉着整个世界的门在朝我打开，共产主义和毛已经不再是我心里的障碍，我更了解了中国，我非常高兴，我可以拥抱这些，我想就可以拥抱一切。” 同事笑了，笑得非常灿烂。从我认识他以来，每次总是看到他绅士的、彬彬有礼的微笑，从来没有看到过他笑的这么彻底，像绽裂开的花。
Mao did not force anyone to give birth to more kids; it is the people who did that themselves. Mao just rejected a birth control poplicy, but look at the other countries some of which even encourage people to have more kids, but the people don't do it, so their population is not increasing.
wenjuyuan 发表评论于
人口多是人民太29233;生了，不是21527;
Green_sky 发表评论于
I think his biggest mistake was that he did not retire/resign in 1949.
回复MichaelC的评论:
Global Warming?作者这是什么理论？控制Global Warming最好的方法是人类都死绝！中国人自己的土地，自己的国家，爱怎么生怎么生，其它国家没有权利指责中国的人口政策。这就如同中国人明知邪恶的华尔街是这次全球金融危机的祸首，却不能指责美国金融系统一样。作者不应该如此在意友邦惊咤论
