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Saharan Dust And The Amazon | Earth Wise

October 23, 2020 By EarthWise Leave a Comment

We talk about globalization primarily in the context of how human activities connect up distant parts of the world. But there are natural processes that are global in scope as well. One of these is the transportation of mineral-rich dust from the Sahara Desert in North Africa to the Amazon Basin in South America.

Every year, this dust is lifted into the atmosphere by winds and carried on a 5,000-mile journey across the North Atlantic. It turns out that this dust plays a critical role in the Amazon basin ecosystem. The Amazon Basin in turn plays a major role in global climate. Its trees and plants remove huge quantities of carbon dioxide from the atmosphere and stores the carbon in vegetation.

The transcontinental journey of dust is important because of what is in the dust. The dust picked up from ancient lake beds in Chad comes from rock minerals formed by dead microorganisms and is loaded with phosphorus. Phosphorus is an essential nutrient for plant growth and is in short supply in Amazonian soils. Local nutrients like phosphorus in the Amazon mostly come from fallen, decomposing leaves and organic matter but tend to be washed away by rainfall into streams and rivers.

Studies have shown that the phosphorus that reaches Amazon soils from Saharan dust is essential to replace the amounts lost to rain and flooding.

Recent research has found that the quantities of dust transported to South America are inversely linked to rainfall in North Africa and is likely to be affected by climate change. Changes in dust transport could affect plant growth in the Amazon and the amount of CO₂ removed from the atmosphere. The forces that affect the climate are truly global in nature.

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Study quantifies Saharan dust reaching Amazon

Earth Wise is a production of WAMC Northeast Public Radio.

Alaska Is Getting Wetter | Earth Wise

August 31, 2020 By EarthWise Leave a Comment

Siberia has been in the news for record-setting heat waves and wildfires, but it is not the only northern region experiencing unusual weather. Alaska, apart from setting its own warm weather records, is experiencing the rainiest five years in its century-long meteorological record.

Extreme weather in the Arctic is being driven by an aspect of climate change called Arctic amplification, which leads to temperatures rising faster than the global average. The physical basis of Arctic amplification is well understood, but its effects over time are much less predictable.

The past five years included two summers with average precipitation, one that was a little drier than usual, and two of the wettest summers on record. Researchers have taken measurements of how far below the surface permafrost has thawed by the end of summer over a wide range of Alaskan environments.

About 85% of Alaska sits upon permafrost and the increasing rainfall over the past five years is leading to a deeper thaw of permafrost across the state. The wettest summer on record was 2014 and permafrost didn’t freeze back to previous levels even when the next couple of summers were relatively drier.

The study demonstrated how different types of land cover govern relationships between summer rainfall and permafrost thaw. As Alaska becomes warmer and wetter, the vegetation cover is projected to change, and the increasing occurrence of wildfires will disturb larger areas of the landscape. These conditions are likely to lead to a feedback loop driving more and more permafrost thawing.

Fundamental changes to Alaskan ecosystems are occurring on an unprecedented timescale – not gradually over decades or lifetimes, but over mere months or years.

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Alaska is getting wetter. That’s bad news for permafrost and the climate.

Photo, posted June 10, 2011, courtesy of Peter Rintels via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

More Extreme Wildfire Seasons | Earth Wise

April 29, 2020 By EarthWise Leave a Comment

According to a new study led by researchers at Stanford University, autumn in California feels more like summer now as a result of climate change, and this hotter and drier weather increases the risk of longer and more dangerous wildfire seasons.

The research team, whose work was recently published in the journal Environmental Research Letters, found that the frequency of extreme fire weather conditions in the fall in California has doubled since the early 1980s. Average temperatures during the season have increased by more than 2 degrees Fahrenheit, and rainfall has fallen by approximately 30%. The most pronounced warming has occurred in the late summer and early fall. That finding means that tinder-dry conditions coincide with the strong “Diablo” and “Santa Ana” winds that are typical in California at this time of year.

In recent years, these conditions have fed large and fast-moving wildfires across California. The state’s two largest wildfires, two most destructive wildfires, and the most deadly wildfire all occurred during 2017 and 2018, resulting in more than 150 deaths and $50 billion in damage.

Because summertime has typically been peak fire season, the recent spate of autumn fires is putting a strain on firefighting resources and funding. The ongoing COVID-19 pandemic could further strain emergency resources. Since fire-prone regions have historically shared wildfire-fighting resources throughout the year, the consequences of California’s extended wildfire season could have a global impact. (For example, California’s recent autumn wildfires have coincided with the beginning of wildfires in Australia).

The researchers highlight some opportunities to manage the intensifying wildfire risk in California, including limiting the trajectory of global warming in keeping with the targets identified in the United Nations’ Paris agreement.

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Researchers forecast longer, more extreme wildfire seasons

Photo, posted September 12, 2019, courtesy of the California National Guard via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hundred-Year Floods Becoming One-Year Floods

September 26, 2019 By EarthWise Leave a Comment

By definition, 100-year floods are intense flooding events that historically tend to happen once every 100 years. Put another way, a 100-year flood has a 1 percent chance of happening in any given year.

According to new research published in the journal Nature Communications, rising global temperatures may turn 100-year floods into annual occurrences in parts of the United States. The increase in severe coastal flooding events by the end of this century will be a result of rising sea levels and stronger, more frequent tropical storms and hurricanes.

The study, led by researchers at Princeton University and MIT, examined flood risk for 171 counties along the US East Coast and the Gulf of Mexico. Their analysis concluded that 100-year floods will become annual events in New England. In the US Southeast and Gulf of Mexico, counties could experience such floods as often as every year up to as seldom as every 30 years.

Previously, most analysis of coastal flooding has looked only at the impact of sea level rise on flood risk. This new research combined the risk of rising seas with projected changes in coastal storms over the course of this century. Data from the Gulf of Mexico revealed that the effect of stronger storms is comparable with or even more significant than the effect of sea level change for 40% of the counties studied. So, neglecting the effects of storm climatology change is likely to significantly underestimate the impact of climate change in many places.

The hope is that more comprehensive flood risk data can be used to create more effective climate resiliency strategies all the way down to the county level.

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100-Year Floods Could Soon Happen Annually in Parts of U.S., Study Finds

Photo, posted August 31, 2017, courtesy of the U.S. Department of Agriculture 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.

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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.

Intense Rainfall And Crops

July 2, 2019 By EarthWise Leave a Comment

The warming of the planet does not necessarily imply local weather will be warmer or drier than average. While heatwaves and droughts are increasingly common events in many places, so are intense rain events.

A new study led by scientists at the University of Illinois has found that intense rainfall is as damaging to the U.S. agricultural sector as heatwaves and excessive droughts.

The study examined more than three decades of crop insurance, climate, soil, and corn yield data. Researchers found that since 1981, corn yields in the U.S. Midwest were reduced by as much as 34% during years with excessive rainfall. Years with drought and heatwaves experienced yield losses of up to 37%.

Intense rain events can physically damage crops, delay planting and harvesting, restrict root growth, and cause oxygen deficiency and nutrient loss. The study estimated that between 1989 and 2016, excessive rainfall caused $10 billion in agricultural losses. However, excessive rainfall can have either negative or positive impact on crop yield and the effects can vary regionally.

Parts of the Midwest have already experienced a 42% increase in the heaviest precipitation events since 1958. Climate change models predict that much of this region will experience even more frequent and intense precipitation events in the coming decade.

According to the study, excessive rainfall is the major cause of crop damage currently in the U.S. for corn, and also has broad impacts for other staple crops such as soybeans and wheat. The authors suggest that as rainfall becomes more extreme, reforms will be needed in the U.S. crop insurance industry in order to better meet planting challenges faced by farmers.

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Intense Rainfall Is As Damaging to Crops As Heatwaves and Drought, and Climate Change Is Making It Worse

Photo, posted October 2, 2013, courtesy of the United Soybean Board via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Rainy May

June 27, 2019 By EarthWise Leave a Comment

If it seemed like May was unusually rainy, that’s because it was. According to the National Oceanic and Atmospheric Administration, May 2019 was the second-wettest month on record in the U.S. and contributed to a record-setting wet 12-month period.

The average precipitation for May was 4.41 inches, which is 1.5 inches above normal. The wettest month in 125 years of record keeping was May 2015, which averaged just 0.03 inches more than this past May.

The period from June 2018 through May 2019 saw the wettest 12-month period on record in the U.S. with 37.68 inches, nearly 8 inches above average. Increases in heavy rain events are among the most anticipated and well-documented impacts from climate change.

During May, the stormy pattern led to widespread flooding in the nation’s heartland. In North Carolina, early-season extreme heat and a rapidly-developing drought was replaced by intense rainfall and flooding.

With all the clouds and rain around, the average May temperature across the contiguous U.S. was 59.5 degrees, which ranked in the bottom third of the 125-year record.

Extreme and unusual weather is becoming commonplace as the climate changes. Duluth, Minnesota had 10.6 inches of snow on May 9, breaking an all-time record for May. Denver had its snowiest May in 77 years. But while the U.S. experienced somewhat cooler weather than usual, the planet as a whole continues to warm. April 2019 was the second hottest April on record, dating back to 1880. The Arctic region saw a record low for sea ice.

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Rain-soaked U.S. had its 2nd-wettest month on record in May

Photo, posted May 20, 2013, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

2018 Was A Wet Year

March 20, 2019 By EarthWise Leave a Comment

Recent news reports noted that 2018 was the fourth hottest year on record. But the changing climate is not just about temperature. 2018 was also the third-wettest year since 1895, when steady record-keeping began.

Overall, the U.S. recorded 4.68 inches more precipitation in 2018 than the 20th century average. But all that rain and snow was nothing like evenly distributed. The eastern half of the country – especially in places like North Carolina and Virginia – saw record amounts of precipitation, while most of the West remained stuck in drought.

The warming climate leads to precipitation extremes at both ends, meaning that wet places are likely to get wetter and dry places drier. There has been a marked upward trend in short-duration extreme events. For example, Cyclone Mekunu dumped almost 13 inches of rain on Salalah, Oman in 36 hours, more than double its annual average rainfall.

In the southeast and eastern U.S., the trend toward stronger storm events is mostly driven by strong warming of the oceans that fringe their shores. Warm oceans evaporate more water into the air and warm air holds more water than cooler air. Warmer, moisture-laden air acts like a blanket over the land, keeping heat trapped near the ground. Many of the states that had their wettest-ever years also set records for high minimum temperatures – their coldest temperatures were less cold than in the past.

Air temperatures are projected to warm up even further in the coming years and, as a result, many scientists are anticipating that extreme precipitation events will only get more extreme. The pattern of drought in the west and wetness in the east is likely to stay.

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2018 was the U.S.’s third-wettest year on record—here’s why

Photo, posted August 18, 2018, courtesy of Jim Lukach via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Endangered Language Species

January 14, 2019 By EarthWise Leave a Comment

There are approximately 7,000 languages spoken in the world today but only about half of them are expected to survive this century. There are many factors contributing to the decline in languages. Perhaps the most significant is globalization, which pushes countries and individuals to shift to national or international languages for economic reasons. Other factors include the lack of support for regional languages in educational systems and mass media, persecution of minority linguistic groups by governments, and disruption of communities during war and emigration.

Predicting which languages will survive and which won’t is difficult. A potential tipping point for languages is the same one affecting the survival of species: climate change. Many small linguistic communities are located on islands and coastlines that are vulnerable to hurricanes and rising sea levels. Other communities live in places where increases in temperatures and erratic rainfall threaten traditional farming and fishing economies.

These climate-related changes will force communities to relocate,creating climate change refugees. Dispersing these people will lead to the splintering of linguistic communities and the need for the use of other languages. Such changes will place additional pressures on languages that are already struggling to survive.

There are endangered languages in many places around the world. Some are exotic such as the island of Sulawesi in Indonesia, which is home to dozens of distinct languages spoken by no more than a few thousand people. Others are much closer to home, such as in indigenous communities in Canada.

The rich tapestry of human language is just another of many things threatened by the changing climate.

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The Conversation: The impact of climate change on language loss

Photo, posted May 19, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cloudbursts And New York City

November 13, 2018 By EarthWise Leave a Comment

Cloudbursts are intense rainstorms that drop enormous amounts of water over a short period of time. Climate change is expected to make cloudbursts occur more frequently. Cities around the world are looking for better ways to cope with weather phenomena like cloudbursts.

Drought In Europe

August 22, 2018 By EarthWise Leave a Comment

Even as Californians fought giant wildfires and Japan struggled with record high temperatures, the unusual summer heat in central and northern Europe has led to the worst drought conditions in over 40 years.

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Hurricanes Are Slowing Down

July 17, 2018 By EarthWise Leave a Comment

According to a new study recently published in the scientific journal Nature, some hurricanes are moving slower and spending more time over land, which is leading to catastrophic rainfall and flooding. The speed at which hurricanes track along their paths – known as translational speed – can play a major role in a storm’s damage and devastation. 17

Green Solutions To Storm Water Runoff

July 5, 2018 By EarthWise Leave a Comment

Philadelphia, America’s fifth largest city, has struggled with storm water runoff problems since the days of Benjamin Franklin. The city’s numerous streams that run into the Schuylkill and Delaware Rivers were eventually covered with brick arches or cemented into underground sewers. The network of underground-to-riverfront outfalls through increasingly-larger pipes is pretty much how all U.S. cities have been coping with storm water for over 200 years.

Saving Wheat

July 3, 2018 By EarthWise Leave a Comment

Rising temperatures, drought, pests and diseases are moving north into the U.S. heartland and are increasingly posing a threat to the wheat crop. An insect called the Hessian fly is reducing crop yields by 10% a year in the Midwest. Average temperatures in the Midwest have risen by 2 degrees since 2000, and periods of time between rainfalls is lengthening. Conditions in some areas of the Midwest are getting to be more like those in the Middle East.

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The Sahara Desert Is Expanding

May 15, 2018 By EarthWise Leave a Comment

Deserts are barren areas of land where little precipitation occurs, resulting in living conditions that are hostile for plant and animal life. These regions are typically defined by low average annual rainfall—usually 100 millimeters (less than 4 inches) of rain per year or less.

Extreme Weather Increasing

May 11, 2018 By EarthWise Leave a Comment

It sure seems like extreme weather is increasingly common: floods, droughts, extreme rainfall, powerful snowstorms, hurricanes and so on. But we tend to focus on recent events and often give them undue emphasis. So, it is reasonable to ask whether extreme weather really is more common these days.

Air Pollution Reducing Global Warming

April 12, 2018 By EarthWise Leave a Comment

Pollution particles emitted by diesel cars and trucks, coal-fired power plants, factories, primitive cook stoves, and the burning of forests are major contributors to the pervasive air pollution that plagues many cities and regions of the world. In India and China, such pollution leads to hundreds of thousands of deaths each year. And countries around the world are working hard to reduce pollution.

Global Warming And The Nitrogen Problem

September 13, 2017 By EarthWise

Excess nitrogen in the environment is a big problem. The most visible aspect of the problem is the spread of toxic algae blooms in oceans, lakes and other bodies of water. But there are other effects as well such as unwanted alterations to ecosystems.

Sahara Greening And Tropical Cyclones

July 25, 2017 By EarthWise

Global weather patterns are influenced by environmental conditions in places around the world. One of the world’s major weather creators is the Sahara Desert. The Sahara is the largest hot desert in the world. The only larger deserts of any sort are in the polar extremes of the planet and are thus not hot deserts at all.

Saving Saharan Oases

February 6, 2017 By EarthWise

An oasis is an isolated area of vegetation in a desert, typically surrounding a spring or similar water source such as a pond or a small lake. Oases can provide habitat for animals as well as people. Oases have long been essential for trade and transportation routes in desert areas; caravans typically travel via oases so that supplies of water and food can be replenished.

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