tropics

Coffee, cocoa, and pollinators

November 20, 2023 By EarthWise Leave a Comment

Multiple forces have been at play that have been detrimental to pollinators including climate change, land use change, pesticide use, and more. There have been substantial declines in both the abundance and diversity of insect pollinators. There is increasing public awareness of this issue, but it hasn’t really risen all that high among many people’s concerns.

A new study by University College London looked at the effects of the global decline in pollinators on thousands of crop-growing sites around the world involving thousands of insect pollinator species.

About 75% of all crops grown depend on pollinators to some degree. The UCL research created a model that looks at which pollination dependent crops are most threatened over the next 30 years in order to provide a warning to both the agricultural and conservation communities.

The research indicates that the tropics are likely to be most at risk with regard to reduced crop production caused by pollinator losses. This is mostly due to the interaction of climate change and land use. The risks are highest in sub-Saharan Africa, northern South America, and southeast Asia.

These areas are where the world gets most of its coffee and cocoa, two crops that are near and dear to most of us. These crops, as well as others such as mangoes, play vital roles in both local economies and global trade and reducing them could lead to increased income insecurity for millions of small-scale farmers in these tropical regions.

If pollinator loss isn’t high up on your list of global concerns, perhaps you should think about it next time you have a cup of coffee or enjoy some chocolate.

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Coffee and cocoa plants at risk from pollinator loss

Photo, posted May 23, 2013, courtesy of McKay Savage via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Geoengineering could create winners and losers

November 13, 2023 By EarthWise Leave a Comment

Geoengineering – deliberate interventions to alter the climate and curb climate change – is a controversial topic, to say the least. Once practically considered taboo even to discuss, there in increasing interest in at least exploring various ideas about how to halt or reverse climate change through direct actions that impact global temperatures.

Putting aside the very real concerns about the risks and dangers associated with such action, there is also the issue that climate interventions may create dramatically different effects across the globe, benefitting some areas and adversely affecting others.

A recent study by scientists at Rutgers University tackled this very issue. Published in the journal Nature Food, it described the results of computer models simulating the impacts of stratospheric aerosol intervention (SAI), which is spraying sulfur dioxide into the stratosphere, where it would partially shield the Earth from the Sun, lowering temperatures.

The study looked at 11 different SAI scenarios and found that none of them benefitted everyone. Uncontrolled global warming favors crop production in cold, high-latitude areas such as Canada, Russia, Scandinavia, and our northern border states. Moderate amounts of SAI favors food production in the mid-latitudes (such as in the US and Europe.) Large amounts of intervention favors agricultural production in the tropics.

Even if geoengineering might not have dire consequences – which is by no means certain – it would create winners and losers. Nations may have different ideas of what constitutes an optimal global temperature. So, who gets to decide where to set the global thermostat? The prospects for conflict loom large.

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Climate Intervention Technologies May Create Winners and Losers in World Food Supply

Photo, posted November 18, 2021, courtesy of Conall via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Value Of Seagrass | Earth Wise

August 7, 2023 By EarthWise Leave a Comment

Seagrasses are found in shallow salty and brackish waters in many places around the world, from the tropics to the Arctic Circle. They get their name from their long green, grass-like leaves. They are not seaweeds at all but are more closely related to flowering plants on land.

We hear a lot about threatened ocean ecosystems and most of the attention is on coral reefs and coastal mangrove forests. Seagrass meadows get much less press, but they in fact provide wide-ranging services to society and store a great deal of carbon.

A new study by the University of Michigan demonstrates that seagrass ecosystems should be high up on the global conservation agenda. The study puts a dollar value on the many services – which include storm protection, fish habitat, and carbon storage – provided by seagrasses in the Caribbean. The numbers are enormous.

The researchers estimate that the Caribbean holds up to half of the world’s seagrass meadows by surface area, and it contains about a third of the global carbon storage by seagrasses. They calculated that the Caribbean seagrasses provide about $255 billion in services to society each year, which includes $88 billion in carbon storage.

In the Bahamas alone, ecosystems services provided by seagrasses are valued at more than 15 times the country’s 2020 gross domestic product.

Blue carbon is the name used to describe carbon stored in coastal and open-ocean ecosystems. The idea of selling blue carbon offset credits, which monetize the carbon stored in this way, is gaining traction. For many Caribbean nations, this is likely to provide impetus for protecting seagrass ecosystems from human impacts, including nutrient pollution and overfishing.

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Caribbean seagrasses provide services worth $255B annually, including vast carbon storage, study shows

Photo, posted June 27, 2023, courtesy of Daniel Eidsmoe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Global Stilling | Earth Wise

October 20, 2022 By EarthWise Leave a Comment

During the summer of 2021, much of Europe experienced a “wind drought” – wind speeds in many places were about 15% below average. In the UK in particular, winds were unusually calm and wind energy production was dramatically reduced.

Globally, wind speeds have been dropping by about 2.3% per decade since the 1970s. In 2019, however, global average windspeeds actually increased by about 6%. The question is whether a trend of slowing winds – so-called global stilling – is associated with climate change or is just natural variability in action.

Wind results from uneven temperatures in air masses. Much of the world’s wind comes from the difference between the cold air at the poles and the warm air at the tropics. Because the Arctic is warming much faster than the tropics, it is possible that winds will continue to decline around the world.

Another factor people cite is the increase in surface roughness. The number and size of urban buildings continues to increase, which acts as a drag on winds.

Some models predict that wind speeds will decrease over much of the western U.S. and East Coast, but the central U.S. will see an increase. Experts do not all agree about what is happening with global winds. Many believe that the observed changes to date have been within the range of variability. Furthermore, some places have been windier than usual.

All of this really matters for many reasons. Europe is increasingly dependent upon wind power as an alternative to fossil fuels. A 10% drop in wind speed results in a 30% drop in energy generation. Whatever their cause may be, wind droughts cannot be ignored.

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Global ‘Stilling’: Is Climate Change Slowing Down the Wind?

Photo, posted June 28, 2008, courtesy of Patrick Finnegan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Decreasing Forest Area Per Capita | Earth Wise

September 7, 2022 By EarthWise Leave a Comment

Over the past 60 years, global forest area has decreased by 315,000 square miles, an area about twice the size of California. Combined with global population growth over that period, this has resulted in more than a 60% decline in global forest area per capita.

The continuous loss as well as degradation of forest affects the integrity of forest ecosystems and reduces their ability to generate and provide essential services and sustain biodiversity. It impacts the lives of at least 1.6 billion people worldwide – primarily in developing countries – who depend upon forests in multiple ways.

According to the new study published in the journal Environmental Research Letters, forest losses have been occurring primarily in lower-income countries in the tropics while forest gains have occurred in higher-income countries in the mid-latitudes or extratropics.

More than half of the world’s forest losses were in Brazil, home to the Amazon rainforest. In the past 60 years, that country has had a net loss of 170,000 square miles of forest. While most high-income countries had net forest gains, Canada actually had a net loss of about 11,000 square miles of forest.

Economic growth has a stronger association with net forest gain than with net forest loss. Therefore, the study highlights the need to strengthen the support given to lower income countries, especially in the tropics, to help improve their capacity to minimize or curtail their forest losses. To help address this ongoing displacement of forest losses to lower income countries, higher-income nations need to reduce their dependence on imported tropic forest products.

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New study finds global forest area per capita has decreased by over 60%

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And The South Pole | Earth Wise

August 10, 2020 By EarthWise Leave a Comment

According to a study led by researchers at Ohio University, the South Pole has warmed more than three times the global average over the past 30 years. While the warming was driven by natural tropic climate variability, the researchers argue that rising greenhouse gas emissions likely intensified the warming.

The climate in the antarctic has some of the largest ranges in temperature during the year. Some regions, like most of West Antarctica and the Antarctic Peninsula, experienced warming during the late 20th century. But the South Pole, which is located in the remote and high-altitude interior of the continent, actually cooled until the 1980s. The South Pole, as the study highlights, has warmed substantially ever since.

For the study, which was recently published in the journal Nature Climate Change, the researchers analyzed climate models and weather station data at the South Pole. They found that, between 1989 and 2018, the South Pole had warmed by 1.8 degrees Celsius. This warming trend of 0.6 degrees Celsius per decade is three times the global average.

According to the study, the robust warming of the Antarctic interior has been mainly driven by the tropics. Warm ocean temperatures in the western tropical Pacific Ocean have altered the winds in the South Atlantic, increasing the delivery of warm air to the South Pole. These atmospheric changes are an important part of what’s driving the climate anomalies in the region.

But the researchers argue that the warming trends are unlikely a result of natural climate change alone. The effects of anthropogenic – or human-caused – climate change in addition to the natural changes have combined to make this one of the strongest warming trends globally.

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Extreme warming of the South Pole

Photo, posted February 7, 2011, courtesy of Eli Duke via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Disappearing Rainforests | Earth Wise

July 2, 2020 By EarthWise Leave a Comment

Forest loss is a major contributor to climate change, and it is continuing at a rapid pace. The tropics lost about 30 million acres of tree cover in 2019, a third of which was within humid tropical primary forests, which are especially important for biodiversity and carbon storage. To put that loss in a human-scale perspective, it is the equivalent of losing a football field of primary forest every six seconds for the entire year.

The losses last year were 2.8% higher than in the previous year, and these losses have continued over the past 20 years despite worldwide efforts to halt deforestation.

Brazil single-handedly accounted for over a third of all global loss of humid tropical primary forests. Bolivia experienced record-breaking tree cover loss due to fires. The losses in its forests were 80% greater than in any previous year. The fires were often started by people who were trying to clear land for agriculture but had the fires go out of control. Several countries in Africa’s Congo Basin also experienced sustained or worsening forest loss.

Indonesia, often the focus of the world’s attention for its deforestation activities, actually saw a 5% reduction in primary forest loss in 2019. It was the third year in a row for lower losses. The now-permanent moratorium on clearing forests for oil palm plantations and logging seems to be working.

Going forward, the coronavirus pandemic poses additional threats to the world’s forests in the near future. There may be a tendency to sacrifice forests in pursuit of economic recovery, which will only lead to future complications for the health and livelihoods of millions of people around the world.

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We Lost a Football Pitch of Primary Rainforest Every 6 Seconds in 2019

Photo, posted February 7, 2011, courtesy of Chad Skeers via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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Metal From Plants | Earth Wise

March 31, 2020 By EarthWise 2 Comments

Large amounts of metal in soil are generally bad for plants. But there are about 700 species of plants that thrive in metal-rich soils. These plants don’t just tolerate minerals from soil in their bodies but actually seem to hoard them to ridiculous levels.

In areas where soils are naturally rich in nickel, typically in the tropics and Mediterranean basin, plants have either died off or have adapted to become nickel loving. Slicing open a tree with this adaptation produces a neon blue-green sap that is actually one-quarter nickel, which is far more concentrated than the ore that typically feeds commercial nickel smelters.

A group of researchers from the University of Melbourne and other institutions is investigating whether this phenomenon is not just interesting but might also be of real commercial value. They established a plot of land in a rural village in Borneo and have been harvesting growth from nickel-hyper accumulating plants. Every six to twelve months, a farmer shaves off one foot of growth from these plants and either burns or squeezes the metal out. After a short purification, they end up with about 500 pounds of nickel citrate, potentially worth thousands of dollars on international markets.

Phytomining – extracting minerals from hyper-accumulating plants – cannot fully replace traditional mining techniques. But the technology could enable areas with toxic soils to be made productive and might allow mining companies to use plants to clean up their former mines and waste while actually collecting some revenue.

There are other plants that suck up cobalt, zinc, and similarly crucial metals. With growing demand for metals, perhaps it is time to harvest them on the farm.

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Down on the Farm That Harvests Metal From Plants

Photo courtesy of the University of Queensland.

Earth Wise is a production of WAMC Northeast Public Radio.

One Million Extinctions

June 14, 2019 By EarthWise Leave a Comment

A group of 145 expert authors from 50 countries has produced a report based upon a review of 15,000 scientific and government sources that is the first comprehensive look at the state of the planet’s biodiversity in 15 years. The conclusions are alarming.

Thanks to human pressures, one million species may be pushed to extinction in the next few years, something with serious consequences for human beings as well as the rest of life on earth.

Based upon scientific studies as well as indigenous and local knowledge, the evidence is overwhelming that human activities are the primary cause of nature’s decline. The report ranked the major drivers of species decline as land conversion, including deforestation; overfishing; bush meat hunting and poaching; climate change; pollution; and invasive alien species.

The tremendous variety of living species on our plant which number at least 8.7 million and perhaps many more – biodiversity – constitutes a life-supporting safety net that provides our food, clean water, air, energy, and more.

In parts of the ocean, little life remains but green slime. Some remote tropical forests are nearly silent because insects have vanished. Many grasslands are becoming deserts. Human activity has severely altered more than 75% of Earth’s land areas and has impacted 66% of the oceans. The world’s oceans increasingly are characterized by plastics, dead zones, overfishing, and acidification.

The main message of the 1,500-page report is that transformative change is urgently needed. In order to safeguard a healthy planet, society needs to shift from a sole focus on chasing economic growth. This won’t be easy, but we must come to the understanding that nature is the foundation for development before it is too late.

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One million species at risk of extinction, UN report warns

Photo, posted January 1, 2014, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving Beaches With Seagrass

February 22, 2019 By EarthWise Leave a Comment

Almost a quarter of the Gross Domestic Product of places around the Caribbean Sea is earned from tourism. Preserving the beaches in the region is an economic imperative. With increasing coastal development, the natural flow of water and sand is disrupted, natural ecosystems are damaged, and many tropical beaches simply disappear into the sea.

With such high stakes, expensive coastal engineering efforts such as repeated replenishing of sand and the construction of concrete protective walls are common strategies. Rising sea levels and increasingly powerful storms only increase the threat to tropical beaches.

Researchers from The Netherlands and Mexico recently published a study in the journal BioScience on the effectiveness of seagrass in holding onto sand and sediment along shorelines.

Seagrasses are so-named because most species have long green, grass-like leaves. They are often confused with seaweeds but are actually more closely related to flowering plants seen on land. Seagrasses have roots, stems and leaves, and produce flowers and seeds. Seagrasses can form dense underwater meadows and are one of the most productive ecosystems in the world. Seagrasses provide shelter and food to an incredibly diverse community of animals, from tiny invertebrates to large fish, crabs, turtles, marine mammals and birds.

The researchers performed measurements of the ability of seagrass along Mexico’s Yucatan Peninsula coastline to keep sand in place and prevent erosion. They found that the amount of erosion was strongly linked to the amount of vegetation. Quite often, seagrass beds have been regarded as a nuisance, rather than a valuable asset for preserving valuable coastlines. The study opens opportunities for developing new tropical beach protection schemes in which ecology is integrated into engineering solutions.

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Seagrass Saves Beaches and Money

Photo, posted October 13, 2010, courtesy of NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And The Polar Vortex

February 20, 2019 By EarthWise Leave a Comment

This winter has seen some brutally-cold weather in many places, some of it record-breaking. Predictably, some climate-change deniers point to this as evidence that the climate is not warming at all. They are quite wrong.

For starters, it is essential to understand the difference between climate and weather. Climate is the average weather patterns in a region over extended periods of time. Weather is the short-term fluctuations in temperature, precipitation, barometric pressure, wind, and so forth. There can be extremes in weather of many types in a given climate region including very cold weather in a warming climate.

The recent cold weather events in the U.S. stem from the flow of Arctic air into southern regions. Such flows are impacted dramatically by the behavior of the jet stream. These high-altitude east-to-west winds are driven by temperature differences between cold arctic air and warm tropical air and play a huge role in our weather.

The Arctic has seen extremely unusual warming due to the changing climate, weakening and fracturing the polar vortex, which is a persistent low-pressure area near the pole. The changing air flow from the Arctic causes the jet stream to take wild swings. When it swings further south, it causes cold air to reach farther south. These swings tend to hang around for a while, leading to extended periods of cold weather in the winter and, actually, extended periods of warm weather or even droughts in the summer. Studies have predicted that extreme, deadly weather events could increase by as much as fifty percent by 2100.

As more Arctic air flows into southern regions, North America can expect to see harsher winters. The warming climate doesn’t always lead to warmer weather.

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