Why are many environmentalists opposed to artificial cloning?

Dear EarthTalk: Why are many environmentalists against artificial cloning of living organisms? Isn’t it a good way to save endangered species?

Louis Bachman

Chico, Cal.

As many endangered species near extinction, cloning seems like a viable solution to rebuild populations. Using DNA from already deceased animals, cloning can even increase the diversity of a gene pool. There are only seven white rhinos confirmed to be alive today, for example, so adding only a few more through cloning could mean the difference between extinction and survival of the entire species. 

Why, then, do many environmentalists oppose the artificial cloning of endangered species?

Cloning is often thought of as unnatural and inhumane, but it was, in fact, the first method of reproduction and is still very common in nature today. Asexual reproduction, the oldest form of cloning, is used by aspens, stick insects and Kentucky Bluegrass.

Artificial cloning began in 1928, when Hilde Mangold took a first step: injecting DNA into an egg. By 1952, the first animal was successfully cloned. It was a tadpole. 

Perhaps the most notable clone in recent history, Dolly the sheep, was the first mammal to be cloned from an adult cell. The first endangered animal to be cloned was the gaur, in 2001. 

But along with these successes were many failed and forgotten clones. Even the cloning of common, well-understood animals is difficult. Dolly the sheep was the result of the 434th cloning attempt and only lived to just over half the average lifespan of a sheep. When the animals are endangered and their reproductive physiology is not well understood, cloning gets even more difficult.

Cloning of endangered species has a wildly low success rate; usually under 1 percent. Even successful clones are often not able to themselves reproduce and usually live shorter than average lives. 

Because of the potential for reducing the already low numbers of existing population of endangered species, scientists often use close relatives for eggs and as mothers to gestate the cloned embryos. This often results in the mother rejecting the egg or if the clone is born, reproductive complications.

Due to such inefficiencies, most environmental leaders are not bullish on cloning endangered species. 

“The potential of cloning is intriguing, but it’s been very little tested in terms of its practical application,” says Oliver Ryder, an endangered species expert at the San Diego Zoo. “The way to preserve endangered species is to preserve them in their habitat.” 

Despite not being a viable current method for saving endangered animals, cloning could very well be effective in the future. “Frozen zoos” in San Diego and Brazil hold the genetic material of extinct and endangered animals and could be used if need be and if the technology improves. 

In the meantime, and as Ryder points out, efforts to stop poaching and the destruction of habitats — rather than high-tech fixes like cloning — could go much further to preserve species.

CONTACTS: San Diego Zoo Institute for Conservation Research, institute.sandiegozoo.org.

Dear EarthTalk: What are “smoke waves” from wildfires and how can they be hazardous for our health?

Doug Jenkins

Big Sandy, Tex.

Smoke waves are just what they sound like: huge waves of smoke. Perhaps more dangerous than the fires themselves from which they radiate, smoke waves can cause health problems for people hundreds of miles around. Forest fire flames licking at homes and neighborhoods are always scary, killing dozens of people and causing billions of dollars in property damage across the U.S. every year. But it’s typically the risk from the smoke waves that causes school closures and confines people indoors for days or weeks on end while more frequent and more intense wildfires rage on.

What makes smoke waves so dangerous is that they carry particulate matter (tiny dust particles smaller than 2.5 microns) that people can breathe into their lungs where they can cause respiratory problems and aggravate pre-existing medical conditions. Forest fires and other forms of combustion are the main source of these tiny dust particles—so the more forest fires, the more particulate matter risk. Asthmatic children are especially sensitive to smoke waves; hundreds were hospitalized in California this summer during one of the worst fire seasons on record. The elderly, especially those with heart or lung conditions, are also highly vulnerable to pollution from smoke waves. Smoke waves are most severe for those directly under or in the wave, but pollution can travel for hundreds of miles, poisoning the lungs of people nowhere near the actual fire.

A recent study of smoke waves across the Western U.S. by researchers from Harvard and Yale universities concluded that climate change “will likely cause smoke waves to be longer, more intense, and more frequent.” They found that between 2004 and 2009, smoke waves affected 57 million Americans—more than 15 percent of the U.S. population. But even more troubling is their projection for that number to ramp up another 45 percent by mid-century as the planet continues to warm up. That will mean about 13 million more kids and seniors will be impacted by smoke waves compared with today.

As the climate changes and most places get hotter and drier, forest fires are projected to increase significantly—and with more fire comes more smoke. Anyone living in fire-prone areas needs to be informed and prepared. Sites like AirNow.gov can give current data on air quality and warn of any dangers from smoke waves or other forms of pollution. If a smoke wave is in your area, stay indoors or wear protective clothing and masking to avoid inhalation. 

Because smoke waves are a direct result of human-caused global warming, the best way to minimize them is to slow or stop carbon emissions. While slowing or stopping global warming is a global effort, individuals need to do their part too. Do what you can to minimize energy use and waste, upgrade to more efficient cars, appliances, systems, homes and offices, fly and drive less, walk and bike more... But also vote for carbon taxes and other warming mitigation measures and urge your lawmakers to support sustainability-oriented policy initiatives. If you live in a fire-prone area, you’ll be doing yourself and your loved ones a favor.

CONTACTS: “Particulate air pollution from wildfires in the Western US under climate change,” link.springer.com/article/10.1007/s10584-016-1762-6; AirNow.gov, www.airnow.gov.

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