Tie your tubes and save the planet?

Environmentalists tend to avoid the topic of population control. Too touchy. But the politically incorrect issue is becoming unavoidable as the global population lurches toward a predicted 9 billion people by mid-century. Will there be enough food? Enough water? Will planet-heating carbon dioxide gas become ever more uncontrollable?

Now comes a study by statisticians at Oregon State University focusing on the elephant in the room. If you are serious about your carbon footprint, think: birth control.

The greenhouse gas impact of an extra child is almost 20 times more significant than the amount any American would save by such practices as driving a fuel-efficient car, recycling or using energy-efficient light bulbs and appliances, according to Paul Murtaugh, an OSU professor of statistics. Under current U.S. consumption patterns, each child ultimately adds about 9,441 metric tons of CO2 to the carbon legacy of an average parent--about 5.7 times a person's lifetime emissions, he calculates.

"Many people are unaware of the power of exponential population growth," Murtaugh said. "Future growth amplifies the consequences of people's reproductive choices, the same way that compound interest amplifies a bank balance."

Given how much less the average developing nation consumes per capita, the impact of a child born in the U.S., along with all his or her descendants, is more than 160 times that of a Bangladeshi child, the OSU research found. And the long-term impact of a Chinese child is less than one fifth the impact of a U.S.-born child. But as China, India and other developing nations hurtle toward prosperity, that is likely to change.

--Margot Roosevelt

Photo: Christine Cotter/LA Times

Beijing Olympics were smoggier than we thought

It turns out the Beijing Olympics were smoggier than we thought. Even Los Angeles on a bad day couldn't compete.

Chinese environmental experts under-reported levels of particle pollution by about 30%, according to scientists at Oregon State and Peking universities. New research shows that levels of particle pollution, which enters the lungs and can cause serious health problems, consistently surpassed what the World Health Organization would call "excessive." 

Scientists said particulate matter pollution was twice as high as the Olympics in Athens, three times as high as Atlanta and three-and-a-half times higher than Sydney, Australia. 

And compared with smoggy Los Angeles? The levels exceeded the L.A. average by about two to four times.

To give the Chinese government credit, Beijing had a big decrease in particle pollution leading up to the Games because of limits placed on driving ahead of time, according to the study. Still, it seems shifting winds and fortuitous rains had more impact in scaling back pollution than government restrictions.

The study was jointly funded by the U.S. and Chinese National Science Foundations.

--Amy Littlefield

Photo: Beijing's smog surpassed Los Angeles' levels by two to four times. Credit: Jean Chung / For The Times

Humanity's ever-bigger footprint

Worried about collapsing financial markets? The World Wildlife Fund says that’s nothing compared to the looming ecological credit crunch, as human society continues on a spending binge that vastly exceeds the planet’s ability to provide clean water, air and other essential ingredients for success.

The 45-page Living Planet Report attempts to quantify how the human race’s consumption patterns now “overshoot” the planet’s capacity to regenerate itself, replenishing water and timber as well as absorbing carbon dioxide and other human-caused pollution.

The recent downturn in the global economy, writes James P. Leap, director-general of the World Wildlife Fund International, offers a reminder of the consequences of living beyond our means.

“Yet our demands continue to escalate, driven by the relentless growth in human population and in individual consumption,” he wrote in the report. “Our global footprint now exceeds the world’s capacity to regenerate by about 30 percent. If our demands on the planet continue at the same rate, by the mid-2030s, we will need the equivalent of two planets to maintain our lifestyles.”

The Living Planet Index, produced with the Zoological Society of London and the Global Footprint Network, offers a measure of nature’s overall health. The snapshot finds that wildlife has dropped about a third, freshwater is increasingly scarce in some countries, and about 40% of the oceans are severely affected by overfishing and other human activities.

Most of this, if not all, is attributed to human demands on the planet, the report says. In 1961, the first time such global data were available, most countries managed to live within their ecological means. By 2005, more than three-quarters of the world’s people lived in nations that were “ecological debtors,” meaning their national consumption outstripped their country’s biological capacity.

Although the United States often takes the lead in consumption, the United Arab Emirates edges out U.S. in the ecological footprint per person. That measurement is taken by adding up all of the cropland, grazing land, forests and fishing grounds required to produce food, fiber and timber, as well as the sum of a country's carbon dioxide emissions.

In its global analysis, the report notes that both population and average footprint have increased since 1961. Since around 1970, the global average per-person footprint has been relatively constant while population has continued to grow. That’s because so many of the additional people on the planet, such as those in sub-Saharan African nations, are so poor.

One notable exception is the increasing affluence among China's growing populace. Its population and per-person footprint doubled from 1961 to 2005, resulting in a four-fold increase in its overall ecological footprint.

“With the world already in ecological overshoot," the report concludes, the "continued growth in population and per-person footprint is clearly not a sustainable path."

It offers a prescription to slow, or reverse, the trend:

 Encourage new technology and innovation in developing nations to help them leapfrog over dirty industries that are typically steps on the path to modern industrialized society;
 Design cities, which now house more than half of the world’s population, in such a way to reduce demand on energy, water and other natural resources;
 Help women obtain education, economic power and access to voluntary family planning, as a way to slow population growth.

-- Kenneth R. Weiss

Photo: Planet Earth; Credit: NASA/Corbis