Climate Change to Widen Range of Disease-Carrying Mosquitoes
By 2061-80, an additional half a billion people could be at risk from diseases carried by the Aedes aegypti mosquito, the study says—and could even rise to more than 5 billion under a scenario of high population growth.
There are roughly 3,500 species of mosquito buzzing about on the Earth. One of the most common is the Aedes aegypti.
These blood-sucking insects are canny predators. They are well adapted to urban areas, often lying low under beds and in wardrobes before venturing out in the daytime to seek their prey.
And their preferred prey is, well, you.
The female, which needs the protein in blood to develop its eggs, has acquired something of a taste for humans. They are adept at the “sneak attack”—approaching victims from behind and biting ankles and elbows to avoid being noticed.
Aedes aegypti are “sip feeders,” preferring to take small blood meals from lots of people. This makes them prolific at spreading disease; they are the main carrier of viruses that cause dengue, Zika, yellow fever and chikungunya.
Estimates suggest 390 million people a year are infected with dengue and the recent outbreak of the Zika virus in South America has largely been driven by Aedes aegypti.
Currently, approximately 63 percent of the world’s population live in areas where Aedes aegypti are found. The range of these mosquitoes is largely limited by climate—they like the hot, wet conditions of the tropics and subtropics.
However, a new study, published this week in the journal Climatic Change, suggests their habitat could expand as the climate warms—putting millions more people at risk from the viruses they carry.
To forecast how the global distribution of the Aedes aegypti might change in future, the researchers first assessed existing habitats across the world. They assigned each area to one of the following four categories of Aedes aegypti abundance, based on the suitability of the climate:
- Type 1: Year-round high abundance (e.g. Manila, Philippines);
- Type 2: Year-round presence, but only seasonal high abundance (e.g. Chiang Mai, Thailand);
- Type 3: Seasonal presence, with eggs surviving through winter (e.g. Buenos Aires, Argentina).
- Type 4: Seasonal presence, but no eggs surviving through winter (e.g., Puebla City, Mexico).
You can see how the different categories are currently spread across the world in the map below. Aedes aegypti are most abundant in the areas shaded red, such as northern South America and much of southeast Asia.
Using projections of temperature and rainfall, the researchers simulated the potential change in global Aedes aegypti habitat by 2061-80. They used two scenarios of climate change—one under moderate greenhouse gas emissions (RCP4.5) and another under high emissions (RCP8.5).
The researchers found the potential habitat range for Aedes aegypti increases by 8 percent under RCP4.5 and by 13 percent under RCP8.5. At today’s population, this translates to between 298 million and 460 million additional people exposed.
The maps below show the changes in habitat projected for the two scenarios. The purple shading indicates areas where the mosquitoes are expected to become more prevalent, while the green shading shows the opposite.
The pale purple shading indicates where the climate is currently unsuitable for Aedes aegypti, but is expected to become suitable on a seasonal basis in the future. Lead author Dr. Andrew Monaghan, a scientists at the National Center for Atmospheric Research in Colorado, explained to Carbon Brief:
“Under climate change, projected increases in temperatures, in particular, have the potential to allow the mosquito to establish in regions that were previously too cool. These areas tend to be at the margins of present-day survival in mid-latitude regions in North America, Europe, Asia and Australia. They can also be high elevation cities in the tropics and subtropics, such as Mexico City and Quito.”
In much of the tropics and subtropics, the dark purple shading shows where the habitat shifts from being suitable seasonally, to being suitable year-round. This includes much of central Africa, Central America and China.
Projected drier conditions in the Amazon rainforest mean that some areas will become less prevalent for Aedes aegypti in the future (green shading), the study says.
With rising global population, the habitats of Aedes aegypti will also be home to more people in the future.
At present, approximately 3.8 billion people live in areas exposed to these mosquitoes. Accounting for both climate change and population rise, the researchers estimate that this could increase by 2.2-2.5 billion in 2061-80 (based on a global population of around 8.5 billion) or even by 4.8-5.1 billion in a world where global population surpasses 11 billion.
Such a rise in the number of people exposed to Aedes aegypti would have important implications for public health, said Monaghan:
“All else being equal, climate change and population growth will likely increase the percentage of humans exposed to this important virus vector mosquito.”
Cutting greenhouse emissions will “make a dent” in this increase in exposure, said Monaghan, but improving access to clean water and sanitation can also go a long way to reduce breeding grounds for mosquitoes:
“Aedes aegypti strongly depends on humans for its survival—it breeds in human-made containers, such as tires, buckets, barrels, tarps, etc.—and the female virus transmitters prefer to bite humans. We know that areas with better socioeconomic conditions tend to have fewer breeding sites and lower human exposure to the mosquito.”
Studies like this one can help identify where public health actions need to be targeted, said Dr. Paul Parham, a lecturer in public health at the University of Liverpool, who wasn’t involved in the study. He tells Carbon Brief:
“These sorts of maps and analyses are extremely valuable in helping us plan for future novel mosquito-borne outbreaks—and the adverse health effects of the current Zika virus epidemic is a good example of why such advance planning is essential.”
And while increased abundance of Aedes aegypti won’t necessarily translate to a higher risk of mosquito-borne diseases as the world changes, said Parham, it “certainly provides a strong warning” for the future.
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By Suzanne Cords
One day Lizzie, the first-person narrator of the novel, receives an old book as a gift, with a dedication wishing the reader to be among the survivors. Like the preppers who build bunkers and stockpile supplies in remote areas to be ready for the end of the world, Lizzie is convinced that the end of the world is definitely near in times of a threatening climate disaster.
Lizzie, who lives in New York with her husband and son, is a university campus librarian. She worries about almost everything: her brother, an ex-junkie, or her dental insurance and the future in the face of the apocalypse. She is obsessed with reading reference books and articles about climate change.
She also devours words of wisdom, including about Buddhist spirituality: "A visitor once asked the old monks on Mount Athos what they did all day, and was told: We have died and we are in love with everything." But nothing can lift her spirits.
'Lizzie Is Just Like Us'
Lizzie observes rich New Yorkers plan their move to regions that are less threatened by climate change, something she simply cannot afford. Sometimes she watches disaster movies, which lead her to worry even more.
Above all, she is a gifted observer of her fellow human beings. "Young person worry: What if nothing I do matters? Old person worry: What if everything I do, does?"
Lizzie, the U.S. author told DW, is a bit like the rest of us — well aware of the climate crisis, but because she cares and worries about so many other things, that awareness falls by the wayside. That's how she felt herself, Jenny Offill said, but the more she looked into the issue, the more she saw a need for action on her part, too.
"I also was trying to see if there was a way to make it funny, because, you know, so much of the world of prepping and imagining disaster is actually sort of strangely funny."
The novel was shortlisted for the 2020 UK's Women's Prize for Fiction and has now been released in German translation.
Climate Activist With a Vision
But then, there is also this serious, scientifically based concern about what climate change means. In the past, says Offill, artists were the ones who would predict disasters; today it's the experts, as well as the students she teaches. In the end, their fears and their justified anger motivated her to take a closer look at the issue. Today, she is a climate activist herself, and is involved in initiatives along with many other artists.
Lizzie, the heroine of Weather, hasn't gotten that far. But she voices her fears, and that's a start. "Of course, the world continues to end," says Sylvia, a mentor of Lizzie's, at one point — and commences to water her garden. There is hope after all.
Reposted with permission from Deutsche Welle.
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By Jake Johnson
A federal appeals court on Tuesday dealt the final blow to former President Donald Trump's attempt to open nearly 130 million acres of territory in the Arctic and Atlantic Oceans to oil and gas drilling.
Though the Trump administration appealed the ruling, President Joe Biden revoked his predecessor's 2017 order shortly after taking office, rendering the court case moot. On Tuesday, the Ninth Circuit Court of Appeals agreed to dismiss the Trump administration's appeal.
"Because the terms of the challenged Executive Order are no longer in effect, the relevant areas of the [Outer Continental Shelf] in the Chukchi Sea, Beaufort Sea, and Atlantic Ocean will be withdrawn from exploration and development activities," the court said in its order.
Erik Grafe of Earthjustice, which represented a coalition of advocacy groups that challenged Trump's order, said in a statement that "we welcome today's decision and its confirmation of President Obama's legacy of ocean and climate protection."
"As the Biden administration considers its next steps, it should build on these foundations, end fossil fuel leasing on public lands and waters, and embrace a clean energy future that does not come at the expense of wildlife and our natural heritage," Grafe continued. "One obvious place for immediate action is America's Arctic, including the Arctic Refuge and the Western Arctic, which the previous administration sought to relegate to oil development in a series of last-minute decisions that violate bedrock environmental laws."
VICTORY: 9th Circuit ends fight over President Trump's illegal attempt to open up 128 million acres of Atlantic & A… https://t.co/TvYVt2F1jO— Earthjustice (@Earthjustice)1618347073.0
In January, Biden ordered a temporary pause on new oil and gas leasing on federal lands and waters, a decision environmentalists hailed as a positive step that should be made permanent.
"We call on President Biden to keep his promise: a full and complete ban on fracking and fossil fuel extraction on public lands. Full stop," Food & Water Watch policy director Mitch Jones said at the time. "The climate crisis requires it and he promised it."
Reposted with permission from Common Dreams.
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By 2035, every new car and truck sold in the U.S. could be an EV, a new report says.
Accelerations in technology and especially battery affordability, paired with new policy, mean the dramatic transition would save American drivers $2.7 trillion by 2050, an average savings of $1,000 per household per year.
The ramp up in EV production would also create 2 million new jobs by 2035. Battery prices have fallen 74% since 2014, and their unexpectedly rapid fall is a key driver of the cost savings.
EVs are far simpler mechanically, and more efficient, than internal combustion engine (ICE) vehicles, which translates to reduced climate pollution and lower costs for consumers.
Strengthened vehicle efficiency standards and investment in fast charging infrastructure are needed to accelerate the transition, which would prevent 150,000 premature deaths and save $1.3 trillion in health environmental costs by 2050.
For a deeper dive:
Thousands of Superfund sites exist around the U.S., with toxic substances left open, mismanaged and dumped. Despite the high levels of toxicity at these sites, nearly 21 million people live within a mile of one of them, according to the U.S. Environmental Protection Agency (EPA).
Currently, more than 1,300 Superfund sites pose a serious health risk to nearby communities. Based on a new study, residents living close to these sites could also have a shorter life expectancy.
Published in Nature Communications, the study, led by Hanadi S. Rifai, a professor of civil and environmental engineering at the University of Houston, and a team of researchers, found that living in nearby zip codes to Superfund sites resulted in a decreased life expectancy of more than two months, the University of Houston reported.
"We have ample evidence that contaminant releases from anthropogenic sources (e.g., petrochemicals or hazardous waste sites) could increase the mortality rate in fence-line communities," Rifai told the University of Houston. "Results showed a significant difference in life expectancy among census tracts with at least one Superfund site and their neighboring tracts with no sites."
The study pulled data from 65,000 census tracts – defined geographical regions – within the contiguous U.S., The Guardian reported. With this data, researchers found that for communities that are socioeconomically challenged, this life expectancy could decrease by up to a year.
"It was a bit surprising and concerning," Rifai told The Guardian. "We weren't sure [when we started] if the fact that you are socioeconomically challenged would make [the Superfund's effects] worse."
The research team, for example, found that the presence of a Superfund site in a census tract with a median income of less than $52,580 could reduce life expectancy by seven months, the University of Houston reported.
Many of these toxic sites were once used as manufacturing sites during the Second World War. Common toxic substances that are released from the sites into the air and surface water include lead, trichlorethylene, chromium, benzene and arsenic – all of which can lead to health impacts, such as neurological damage among children, The Union of Concerned Scientists wrote in a blog.
"The EPA has claimed substantial recent progress in Superfund site cleanups, but, contrary to EPA leadership's grandiose declarations, the backlog of unfunded Superfund cleanups is the largest it has been in the last 15 years," the Union wrote.
Delayed cleanup could become increasingly dangerous as climate change welcomes more natural hazards, like wildfires and flooding. According to a Government Accountability Office report, for example, climate change could threaten at least 60 percent of Superfund sites in the U.S., AP News reported.
During the summer of 2018, a major wildfire took over the Iron Mountain Superfund site near Redding, CA, ruining wastewater treatment infrastructure that is responsible for capturing 168 million gallons of acid mine drainage every month, NBC News reported.
"There was this feeling of 'My God. We ought to have better tracking of wildfires at Superfund locations,'" Stephen Hoffman, a former senior environmental scientist at the EPA, told NBC News. "Before that, there wasn't a lot of thought about climate change and fire. That has changed."
In the study, researchers also looked at the impacts of floodings on Superfund sites, which could send toxins flowing into communities and waterways.
"When you add in flooding, there will be ancillary or secondary impacts that can potentially be exacerbated by a changing future climate," Rifai told the University of Houston. "The long-term effect of the flooding and repetitive exposure has an effect that can transcend generations."
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A weather research station on a bluff overlooking the sea is closing down because of the climate crisis.
The National Weather Service (NWS) station in Chatham, Massachusetts was evacuated March 31 over concerns the entire operation would topple into the ocean.
"We had to say goodbye to the site because of where we are located at the Monomoy Wildlife Refuge, we're adjacent to a bluff that overlooks the ocean," Boston NWS meteorologist Andy Nash told WHDH at the time. "We had to close and cease operations there because that bluff has significantly eroded."
Chatham is located on the elbow of Cape Cod, a land mass extending out into the Atlantic Ocean that has been reshaped and eroded by waves and tides over tens of thousands of years, The Guardian explained. However, sea level rise and extreme weather caused by the climate crisis have sped that change along.
"It's an extremely dynamic environment, which is obviously a problem if you are building permanent infrastructure here," Andrew Ashton, an associate scientist at Cape-Cod based Woods Hole Oceanographic Institution, told The Guardian. "We are putting our foot on the accelerator to make the environment even more dynamic."
This was the case with the Chatham weather station. It used to be protected from the drop into the ocean by about 100 feet of land. However, storm action in 2020 alone washed away as much as six feet of land a day.
"We'd know[n] for a long time there was erosion but the pace of it caught everyone by surprise," Nash told The Guardian. "We felt we had maybe another 10 years but then we started losing a foot of a bluff a week and realized we didn't have years, we had just a few months. We were a couple of storms from a very big problem."
The Chatham station was part of a network of 92 NWS stations that monitor temperature, pressure, humidity, wind speed and direction and other data in the upper atmosphere, The Cape Cod Chronicle explained. The stations send up radiosondes attached to weather balloons twice a day to help with weather research and prediction. The Chatham station, which had been observing this ritual for the past half a century, sent up its last balloon the morning of March 31.
"We're going to miss the observations," Nash told The Cape Cod Chronicle. "It gives us a snapshot, a profile of the atmosphere when the balloons go up."
The station was officially decommissioned April 1, and the two buildings on the site will be demolished sometime this month. The NWS is looking for a new location in southeastern New England. In the meantime, forecasters will rely on data from stations in New York and Maine.
Nash said the leavetaking was bittersweet, but inevitable.
"[M]other nature is evicting us," he told The Cape Cod Chronicle.