EarthTalk®
by Roddy Scheer & Doug Moss
Dear EarthTalk: Are the famous Joshua trees of the California desert really going extinct? What can we do to preserve them? -- Bill Alexander, Tempe, AZ
The Joshua tree is an iconic species of the Mojave Desert that stretches across parts of southeastern California, Nevada, Arizona, and Utah. Known for its resilience in an unforgiving desert climate, the Joshua tree is unique in its unusual anatomy and adaptable ecology, but its future looks bleak in the face of increasing global warming.
Indeed, increasing temperatures and decreasing precipitation thanks to climate change have shifted the suitable habitat for a variety of flora and fauna around the world, including the Joshua tree. Biologists fear that little of the Joshua tree’s historical range will be suitable for it within a century. By 2100, climate models show that Joshua Tree National Park will lose the majority of its suitable habitat for its namesake species. The increasing severity and frequency of forest fires pose a threat to the future of the trees as well. Because Joshua trees did not evolve with fire, they are not adapted to its effects, making it difficult for the population to bounce back after such a disturbance. As temperatures increase, biologists predict that the suitable range for Joshua trees will move northward. However, this northward range is not guaranteed to be viable, as the Yucca moth that pollinates Joshua trees does not live up there.
Given the threat to Joshua trees, several entities have embarked on campaigns to try to save the iconic tree. The National Park Service recently embarked on a campaign to protect the tree’s remaining habitat in Joshua Tree National Park, Mojave National Preserve and Death Valley National Park. Meanwhile, researchers and conservationists launched the Joshua Tree Genome Project in 2020 to collect and monitor data from both professional and citizen scientists in an effort to map and monitor existing populations. Project organizers hope to use the data to inform conservation planning by identifying Joshua tree populations best situated to benefit from conservation protections. Yet another effort to help Joshua trees comes from the Mojave Desert Land Trust, which recently launched a planting program to restore lost habitat for the trees across the Mojave.
Public education about the importance of saving threatened species is also key to saving Joshua trees. To wit, the non-profit Joshua Tree National Park Association is working to educate the public about the importance of Joshua trees and the threats they face through free educational programs and resources for visitors to Joshua Tree National Park.
Yet while Joshua trees were granted temporary protection under the state of California’s endangered species laws, they are as yet unprotected at the federal level. As such, the non-profit Center for Biological Diversity has petitioned the U.S. Fish and Wildlife Service to protect the Joshua tree under the Endangered Species Act.
CONTACTS: Joshua Tree Genome Project, joshuatreegenome.org; Saving Iconic Joshua Trees, chicagobotanic.org/blog/plant_science_conservation/saving_iconic_joshua_trees; California Commission Deadlocks on Protecting Western Joshua Trees as Threatened Species, biologicaldiversity.org/w/news/press-releases/california-commission-deadlocks-on-protecting-western-joshua-trees-as-threatened-species-2022-06-16/.
Dear EarthTalk: I’ve heard that gas stoves are bad for indoor air quality, but what about gas furnaces and other gas-powered appliances typically found in homes? – L.J., Ronkonkoma, NY
Natural gas is almost as ubiquitous an energy source in American households as electricity. Indeed, 48 percent of U.S. homes stay warm with gas-powered furnaces while 38 percent do their cooking with gas. But recent revelations about the negative effect cooking with gas can have on indoor air pollution has given rise to new concerns about other types of gas-powered appliances inside our homes as well.
Gas cooktops may be the biggest offender given how much pollution they throw off when we use them, but gas-powered ovens, water heaters, clothes dryers and fireplaces are also worthy of concern. Gas-powered appliances emit carbon monoxide (CO), a colorless, odorless gas that, when inhaled, can cause headaches, dizziness, nausea—even death in high concentrations. Modern furnaces and appliances have safety features to prevent dangerous levels from building up, but they can still emit small amounts of CO.
Another concern with gas-powered appliances is the emission of nitrogen dioxide (NO2). NO2 is a reddish-brown gas that can irritate the eyes, nose and throat. It can also exacerbate respiratory conditions such as asthma and bronchitis. Gas stoves are the primary source of indoor NO2, but gas furnaces and other gas-powered appliances can also produce it. Gas-powered appliances also emit particulate matter (PM), another type of indoor air pollution. PM is a mixture of tiny particles that can be inhaled deep into the lungs. Exposure to PM can cause respiratory and cardiovascular problems, particularly in vulnerable populations such as children, the elderly and those with pre-existing health conditions.
To minimize the negative effects of gas-powered appliances on indoor air quality, it is important to properly maintain and ventilate them. Regular maintenance, such as cleaning and replacing filters, can help ensure that appliances are running efficiently and emitting fewer pollutants. Additionally, proper ventilation can help remove pollutants from the air. Ventilation can be achieved by opening windows or using exhaust fans that vent to the outside.
Another option for reducing indoor air pollution from gas-powered appliances is to switch to electric varieties instead. Electric stoves and furnaces do not produce CO or NO2, and they emit far less PM than gas appliances. While electric appliances may have higher upfront costs, they can be more cost-effective over time due to lower operating costs and reduced maintenance needs.
If you are designing a new home from scratch, it’s a no-brainer these days to choose appliances powered by electricity not gas. But most of us don’t have that luxury, and it’s not easy to decide if it’s worth the expense and hassle of switching out an old gas-powered appliance with a shiny new electric one. The bottom line is “if it ain’t broke, don’t fix it” as swapping out an old one for a new one generates more pollution overall thanks to the lifecycle costs of manufacturing. But if your old appliance has reached the end of its useful life anyway, changing to an electric one may well be the best move.
CONTACTS: Gas stoves can generate unsafe levels of indoor air pollution, vox.com/energy-and-environment/2020/5/7/21247602/gas-stove-cooking-indoor-air-pollution-health-risks; Gas stoves pose health risks. Are gas furnaces and other appliances safe to use? /yaleclimateconnections.org/2023/03/gas-stoves-pose-health-risks-are-gas-furnaces-and-other-appliances-safe-to-use/
Dear EarthTalk: How are wild tiger populations faring today around the world? – P.K. via email
Wild tigers have been roaming the planet for upwards of a million years—about 600,000 years longer than humans. Tigers can be found across East and South Asia, with most of them lurking in the rainforests of India, Thailand and Nepal. But don’t expect to see one anytime soon, as their numbers plummeted during the 20th century from 100,000 worldwide to just 4,500. Hunting has been the main cause of their demise, but threats like habitat loss and global warming could push them to extinction if we don’t act fast.
Also, demand across Asia for tiger parts—traditional medicine practitioners make use of tiger bones, eyes, whiskers and teeth to treat a wide range of ailments regardless of medical effectiveness—has led to an uptick in recent years of so-called “tiger farming” whereby wildlife poachers capture wild tigers and imprison them to breed. The non-profit WWF reports that over 8,000 tigers (almost double the number living in the wild) are imprisoned in tiger “farms” across East and Southeast Asia.
Climate change is also a big threat. Rising sea levels are threatening the mangrove forests where the Bengal tigers of the Sundarban regions of India and Bangladesh reside. WWF projects that habitat loss could completely decimate the Sundarbans given the sea level rise predicted for the region by 2070.
But it’s not all doom and gloom. According to ShareAmerica, tigers have begun to rebound slightly in recent years. The increase can be attributed to the reduction of conflicts over space between humans and tigers and education on the fragile status of these precious creatures (Indonesia’s Ministry of Environment and Forestry has trained over 1,200 community members in reducing conflicts between humans and tigers). The 2021 END Wildlife Trafficking Strategic Review states that since 2015, no tigers have been killed over landscape conflicts. Additionally, Nepal, a natural habitat for tigers, saw their 121 tigers back in 2009 skyrocket to around 355. In nearby India, new research has laid the blueprint for conservation and human development to coexist. Dr. Stotra Chakrabarti with Macalester College emphasized “land-sharing,” in which humans and nature both occupy shared areas. Chakrabarti offers a solution to government officials that finds the Goldilocks zone when considering biodiversity and human growth.
Just because you don’t live near wild tigers doesn’t mean you can’t help in their revival. Refuse to purchase illegally harvested tiger products. And if you do reside in an area with wild tigers, support their protection by voting for legislation prioritizing the safety and increase of their population. Tigers have been decimated by human activity over the years, but we can take actions now to assist in their miraculous upswing. Let’s all do our part to save our endangered friends.
CONTACTS: Tiger populations are on the rise, share.america.gov/tiger-populations-are-on-the-rise/; Nepal Successfully Doubles Their Wild Tiger Population, tigers.panda.org/news_and_stories/stories/nepal_successfully_doubles_their_wild_tiger_population/; New research offers roadmap for wildlife conservation and human development to coexist, www.macalester.edu/news/2023/02/new-research-offers-roadmap-for-wildlife-conservation-and-human-development-to-coexist/.
Dear EarthTalk: What can we do to save dying coral reefs? -- B.H. Jackson, Tullahoma, TN
Coral reefs around the world are indeed still at great risk. A comprehensive survey by Canadian researchers in 2021 shows that the world’s oceans have lost about half of their coral cover since the 1950s. The non-profit Global Coral Reef Monitoring Network reports that upwards of 14 percent of the world's coral reefs perished in just the last decade.
What’s killing our corals? The main stressor is global warming-induced rising sea temperatures. Most coral tolerates a range of 75 to 85 degrees Fahrenheit, and temperatures far above that limit are recorded regularly at various locations around the globe. Other climate-related stressors include the fossil fuel-driven acidification of oceans and more frequent, intense tropical storms. Meanwhile, our irresponsible use of coastal lands and the preponderance of ocean-bound pollution that comes off them, as well as overfishing that decimates marine ecosystems, aren’t helping.
The combined effect of these stressors is so-called coral bleaching. Healthy reefs have a symbiotic relationship with an algae called zooxanthellae that lives within coral tissues. Zooxanthellae is coral’s primary food source, but also saturates the structure of the coral that it uses for protection with color—typically a light golden brown, but patches of red, green or blue aren’t unusual.
When coral is stressed due to high water temperatures or other factors, it expels the zooxanthellae, its main nutrient source. As the color fades away, the remaining coral structure turns white. While this bleached coral isn’t dead, it is in a weakened state more likely to be affected by disease or infection. If environmental conditions improve and the coral is re-inhabited by zooxanthellae, its color can return.
New research is providing a glimmer of hope. A recent study of how heat affects marine ecosystems off the Panama coast shows that some corals there have been able to “shuffle” out one species of zooxanthellae for others more resilient to high water temperatures. But while such findings should be celebrated, we’re still causing too much warming too fast to think nature can repair our damage on its own. Marine biologists say corals could be entirely gone by 2050 without substantive human intervention.
Whether or not you live near the ocean, there are many ways you can help coral. For one, seek seafood that is harvested sustainably, as such fisheries prioritize the safety of the marine environment, using methods that minimize impact and help water ecosystems everywhere (including coral reefs). Another way to be part of the solution is by using so-called “reef-safe” sunscreen. Many mainstream sunscreen products contain oxybenzone, a common UV-blocking chemical. But oxybenzone is toxic to corals and as such exacerbates any bleaching and erosion already underway. A quick scan of the ingredient label on a sunscreen bottle before making a purchase is a small but vital act that promotes coral health. Indeed, any way you can significantly reduce your carbon footprint (less driving, flying, red meat, etc.) helps coral survive by reducing greenhouse gas emissions. If we don’t act fast on global warming, our grandkids may never get to see the colorful corals every previous generation of humans has been able to appreciate.
CONTACTS: Why Are Coral Reefs Dying, unep.org/news-and-stories/story/why-are-coral-reefs-dying; NOAA’s Coral Reef Conservation Program, coralreef.noaa.gov; Bloomberg Ocean Initiative, bloomberg.org/environment/protecting-the-oceans/bloomberg-ocean/coral-conservation/.
EarthTalk® is produced by Roddy Scheer & Doug Moss for the 501(c)3 nonprofit EarthTalk. See more at https://emagazine.com. To donate, visit https://earthtalk.org. Send questions to: question@earthtalk.org.
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