peru

Tracking atmospheric mercury

May 13, 2025 By EarthWise Leave a Comment

Atmospheric mercury is a toxic pollutant released into the air from natural sources—such as volcanoes and wildfires—and from human activities like coal burning and gold mining. Once in the atmosphere, mercury can travel long distances before settling onto land or into water, transforming into toxic forms that threaten ecosystems and human health.

But tracking atmospheric mercury is a costly and challenging endeavor, requiring specialized equipment and trained personnel. Active monitors, which pump air to collect mercury, are expensive and need electricity, while passive samplers, using activated charcoal for remote areas, cost up to $100 each.

Researchers from Cornell University have found a cheap method for tracking toxic atmospheric mercury near gold mining sites throughout the Global South: wild fig trees. In the study, which was conducted in the Peruvian Amazon and recently published in the journal Frontiers in Environmental Science, the research team found that the rings in wild fig trees can serve as natural archives of atmospheric mercury, capturing and preserving historical pollution levels over time.

The technique itself is not actually new. Previous studies have used tree rings to track mercury pollution from coal combustion, particularly in Canada. But the research team wanted to test this method in regions of the Global South, where mercury emissions from gold mining are widespread.

According to the research team, wild fig trees might soon serve as an important biomonitoring tool, helping scientists better understand how mercury disperses across landscapes and through time.

**********

Web Links

Tree rings track atmospheric mercury cheaply

Photo, posted November 13, 2012, courtesy of Steve Kessler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

South American drought

November 13, 2024 By EarthWise Leave a Comment

Vast areas of South America have been gripped in drought conditions for months. Rivers in the Amazon basin fell to record-low levels in October. The drought has amplified wildfires, parched crops, disrupted transportation networks, and interrupted hydroelectric power generation in parts of Brazil, Bolivia, Colombia, Ecuador, Peru, and Venezuela.

The drought is related to the impact of the El Niño that was present for the latter part of 2023 and the first half of this year. El Niño typically shifts rainfall patterns in such a way that there is reduced rainfall in the Amazon. This is especially true during the dry season months of July, August, and September.

Forecasts earlier in the year warned that there would be extreme fire conditions during the dry season. Indeed, the Pantanal region that spans parts of southern Brazil, Paraguay, and Bolivia has experienced one of its worst fire seasons in decades. The lack of rainfall, low soil moisture, and drawdowns of groundwater helped to amplify fires and caused them to spread faster and farther.

The drought has strained power supplies in Brazil and Ecuador because hydroelectric power stations are producing less electricity. Snarled transportation networks with impassible rivers have left some communities struggling to get supplies.

Brazil’s National Center for Monitoring and Early Warning of Natural Disasters has called the current drought the most intense and widespread Brazil has ever experienced. Late October saw 293 Brazilian municipalities facing extreme drought.

**********

Web Links

Intense, Widespread Drought Grips South America

Photo, posted August 13, 2010, courtesy of Colm Britton via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Glaciers in Venezuela

June 24, 2024 By EarthWise Leave a Comment

There are nearly 200,000 glaciers in the world. About 91% of them are in Antarctica and 8% in Greenland. The rest are scattered across nearly 50 countries. The non-polar country with the most glaciers is actually Pakistan, which has over 7,200 of them. But as the world continues to warm, glaciers are shrinking back, and many are disappearing altogether.

Venezuela, once home to six glaciers, has become the first country in the Americas to lose all of its glaciers. Slovenia is considered to be the first country to lose its glaciers in modern times, perhaps as long as 30 years ago. Glacial thawing has been worsening over the past decade throughout the Andes, which cover parts of Colombia, Venezuela, Bolivia, Ecuador, Peru, Chile, and Argentina.

Five of Venezuela’s glaciers had largely melted away by 2011. The Humboldt glacier, which is on the highest peak in the Cordillera de Mérida mountain range in Venezuela, has now been declared as too small to be classified as a glacier. It once covered over a thousand acres; it now has less than 5 acres of ice. The US Geological Survey defines glaciers as ice bodies extending 25 acres or more.

The loss of glaciers in the Andes has serious consequences for communities that live on their slopes and depend upon glacial melt for water and for energy and food production.

At least 80% of glaciers worldwide are on track to mostly disappear by the year 2100 because of global warming. Given that previous forecasts estimated that the Humboldt glacier might last another decade, the prospects for the world’s remaining glaciers are not good.

**********

Web Links

Venezuela becomes first nation in the Americas to lose all glaciers

Photo, posted November 11, 2012, courtesy of Tim Snell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Protecting The Amazon Rainforest | Earth Wise

September 5, 2023 By EarthWise Leave a Comment

The Amazon rainforest absorbs one-fourth of all the carbon dioxide absorbed by the land of the Earth. It is by far the world’s largest rainforest, bigger than the next two largest – in the Congo Basin and Indonesia – combined. Nearly two-thirds of it is found in Brazil but the more than 2 million square miles of rainforest includes portions in 8 countries.

The amount of carbon dioxide absorbed by the Amazon rainforest is 30% less today than it was in the 1990s as a result of deforestation, to a great extent driven by cattle ranching as well as other agricultural activities.

In early August, the leaders of the eight countries that are home to the Amazon River basin agreed to work together to conserve the rainforest. The agreement, called the Belém Declaration, provides a roadmap to stave off the rampant deforestation.

The agreement provides coordination between the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela to establish law enforcement to combat illegal mining and logging as well as to pool development funds for conservation and sustainable employment. Despite the unity portrayed at the meeting, many of the governments in South America are in a precarious position because of various economic and political struggles

Apart from its critical climate impact, the Amazon rainforest is a haven for biodiversity and further deforestation would be disastrous for tens of thousands of species and could transform it into a net emitter rather than absorber of greenhouse gases. Some parts of the region have already reached that point.

**********

Web Links

Amazon Countries, Led by Brazil, Sign a Rainforest Pact

Photo, posted October 17, 2016, courtesy of Yeoboya via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Mercury In The Amazon Rainforest | Earth Wise

March 8, 2022 By EarthWise Leave a Comment

Recent research has found that some of the highest levels of mercury pollution ever recorded are in a patch of pristine Amazonian rainforest. The international team of researchers discovered that illegal goldmining in the Peruvian Amazon is the source of the pollution.

Illegal miners separate gold particles from river sediments using mercury. Mercury binds to gold, forming pellets large enough to be caught in a sieve. The pellets are then burned in open fire ovens, releasing the mercury to the atmosphere, leaving the gold behind. The mercury smoke ends up being washed into the soil by rainfall, deposited onto the surface of leaves, or directly absorbed into leaf tissues.

Deforested areas had low levels of mercury, while the areas with the largest, densest old-growth trees captured huge volumes of atmospheric mercury, more than any other ecosystem studied in the entire world. Mercury levels were directly related to leaf area index: the denser the canopy, the more mercury it holds. Birds from this area have up to twelve times more mercury in their systems than birds from less polluted areas. Such high concentrations of mercury could provoke a decline of up to 30% in these birds’ reproductive success.

Small-scale artisanal gold mining is an important livelihood for local communities. Eliminating it outright may not be a viable solution but coming up with ways to continue to provide a sustainable livelihood while protecting communities from poisonous pollution is essential.

In the meantime, the forests are doing an important service by capturing much of the mercury and preventing it from getting into the general atmosphere and endangering more people and animals. Burning or harvesting the mercury-ridden trees would release the mercury back into the atmosphere.

**********

Web Links

Modern Day Gold Rush Turns Pristine Rainforests into Heavily Polluted Mercury Sinks

Photo, posted August 24, 2016, courtesy of Anna and Michal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Disappearing Mountaintop Glacier Ice | Earth Wise

August 30, 2021 By EarthWise Leave a Comment

A newly released study has found that mountaintop glacier ice in the tropics of all four hemispheres has diminished dramatically over the past 50 years. Among the findings of the study, published in the journal Global and Planetary Change, are that a glacier near Puncak Jaya, in Papua New Guinea, lost about 93% of its ice between 1980 and 2018. Between 1986 and 2019, the area covered by glaciers on top of Mt. Kilimanjaro in Africa decreased by nearly 75%.

The study combined NASA satellite imagery with data from ice cores drilled during field expeditions on tropical glaciers around the world. The combination of measurements demonstrated that climate change is causing these glaciers to disappear and that the ice loss has accelerated in recent years.

The study looked at glacier ice in Kilimanjaro in Tanzania, the Andes in Peru and Bolivia, the Tibetan Plateau and the Himalayas, and ice fields in Papua, New Guinea. Collecting ice cores from these places provides information on the climate in these regions over the centuries and millennia. As snow falls on a glacier each year, it is buried and compressed to form layers that preserve the chemistry of snow, pollutants from the atmosphere, and biological material such as plants and pollen.

Glaciers in the tropics respond more quickly to climate change because they exist in the warmest areas of the world and survive only at very high altitudes. For many of these tropical glaciers, it is too late to prevent their demise. It is not too late to attempt the slow down the buildup of greenhouse gases in the atmosphere that is causing the planet to warm, but we don’t have unlimited time to act.

**********

Web Links

Mountaintop glacier ice disappearing in tropics around the world

Photo, posted February 12, 2009, courtesy of Christoph Strassler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And El Niño

December 2, 2019 By EarthWise Leave a Comment

The term El Niño refers to a large-scale ocean-atmosphere climate interaction linked to a periodic warming in sea surface temperature across the central and east-central equatorial Pacific Ocean. Amazingly, the phenomenon was originally recognized by fishermen off the coast of South America in the 1600s, with the appearance of unusually warm water in the Pacific Ocean.

According to a new study published in the Proceedings of the National Academy of Sciences, climate change is increasing the frequency of extreme El Niño events, leading to intensifying droughts, worsening floods, and shifting hurricane patterns.

The study, led by scientists in China and the US, looked at data from 33 El Niños dating back to 1901. Since the 1970s, El Niños have been forming farther to the west in the Pacific Ocean, where temperatures are warmer. Strong El Niños can cause severe drought in dry climates such as Australia and India, intense flooding in wetter climates such as the US Pacific Northwest and Peru, and more hurricanes to form in the Pacific and fewer in the Atlantic.

Before 1978, 12 out of 14 El Niños formed east of the International Dateline. Since 1978, all 11 have formed in the central or western Pacific Ocean a shift of hundreds of miles. There have been three so-called super El Niños since the shift – in 1982, 1997, and 2015. These have set new average temperature records and triggered catastrophic natural disasters.

With rising global temperatures, El Niños are likely to continue to intensify, with major impacts on human societies around the world.

**********

Web Links

Climate Change is Making El Niños More Intense, Study Finds

Photo, posted January 20, 2016, courtesy of Los Angeles District via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Importance Of The Amazon Rainforest Fires

September 10, 2019 By EarthWise Leave a Comment

The Amazon rainforest covers extensive parts of Brazil, Peru, Colombia, and small parts of six other countries. It is the largest rainforest in the world and is instrumental in driving the weather and climate in South America.

The raging wildfires in the Amazon rainforest are a source of great concern. The Amazon is always prone to wildfires during the dry season in South America, but the extent and number of fires this year cannot be attributed simply to drought. The surge in fires has come from illegal deforestation by loggers and farmers, who are using the cleared-out land for cattle ranching.

Rainforests produce consistently high amounts of rainfall throughout the year by pulling water from the soil and then releasing it into the atmosphere. The Amazon rainforest essentially makes it rain in South America.

Over time, the forest plays a crucial role in cycling carbon out of the atmosphere by turning it into biomass. The Amazon jungle sucks up as much as a quarter of the planet’s atmospheric carbon dioxide.

Pristine rainforest burns less frequently and less intensely than cleared and recovering forest. As more and more of the Amazon rainforest is deforested, it becomes more likely to burn each year.

The major disruption of the water dynamics in South America has the potential to not only drive the weather in South American countries but even potentially influence natural resources like snow packs in the Northern Hemisphere.

The skies of Sāo Paulo, Brazil’s financial hub have been dark at midday because of the Amazon fires. This is like having a fire in California and seeing the smoke in Boston. The Amazon rainforest fires are a big problem for the whole world.

**********

Web Links

The Amazon Rainforest has been burning for weeks. Here’s why that matters.

Photo, posted August 21, 2019, courtesy of NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The U.S. Military And Climate Change

July 9, 2019 By EarthWise Leave a Comment

According to new research by scientists from Durham University and Lancaster University, the United States military is one of the largest climate polluters. The U.S. military consumes more liquid fuels and emits more greenhouse gases than most countries.

The study, published in Transactions of the Institute of British Geographers, finds that if the U.S. military were a country, it would be the 47^th largest emitter of greenhouse gases in the world, falling between Peru and Portugal. And this only takes into account the emissions from its liquid fuel consumption. For this study, the U.S. military’s 2015 consumption was compared with the 2014 World Bank country liquid fuel consumption.

In 2017, the U.S. military purchased more than 269,000 barrels of oil a day, emitting more than 25,000 kt- CO2e by burning those fuels. The Air Force accounted for $4.9 billion worth of this fuel, followed by the Navy at $2.8 billion, the Army at $947 million, and the Marines at $36 million.

The Air Force and the Navy are not only the U.S. military’s largest purchasers of fuel, they also use the most polluting types of fuel. The Air Force is the largest emitter of greenhouse gases at more than 13,000 kt CO2e, nearly double that of the Navy’s 7,800 kt CO2e.

Despite this study’s findings and a general uptick in awareness, it’s unlikely that the U.S. military’s dependence on fossil fuels will change. That’s because the military continues to pursue open-ended operations around the globe, and the lifecycle of its existing military equipment insures dependence on hydrocarbons for many years to come.

***********

Web Links

U.S. military consumes more hydrocarbons than most countries — massive hidden impact on climate

Photo, posted July 8, 2016, courtesy of Alan Wilson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Reducing Slavery In Seafood

August 28, 2018 By EarthWise Leave a Comment

The seafood industry is one of the largest employers in the world. But according to a 2016 report, the seafood industry also contains widespread forced labor. Forty seven seafood-producing countries were reported to utilize forced labor. The seafood hub countries of Indonesia, Thailand, Vietnam, Peru, and the Philippines were also reported to use a significant percentage of child labor.