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A Food For The Future | Earth Wise

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Researchers predict that climate change will negatively impact most staple food crops, including rice, corn, and soybeans.  Therefore, climate resilient food crops – those that are salt, drought, and heat resilient – will have an important role to play in global food security.  Examples of climate resilient crops include quinoa, kernza, amaranth, millet, and tepary beans.    

According to a new study by researchers from Northwestern University, breadfruit – a starchy tree fruit native to the Pacific Islands – will be relatively unaffected by climate change.  Because breadfruit is climate resilient and well-suited to grow in regions with high levels of food insecurity, the research team suggests breadfruit could be a part of the solution to global hunger.

While it has ”fruit” in its name, breadfruit is more like a potato.  It’s starchy and seedless, and is closely related to jackfruit.  Breadfruit is nutrient-rich, and high in fiber, vitamins, and minerals.  It can be steamed, roasted, fried, fermented, and even turned into flour.  People in tropical regions around the world have been eating breadfruit for thousands of years. 

In the study, which was recently published in the journal PLOS Climate, researchers determined the climate conditions necessary to cultivate breadfruit and then looked at how these conditions are predicted to change in the future.  They examined two future climate scenarios: one that reflects high greenhouse-gas emissions and another in which emissions stabilize.

In both scenarios, the regions suitable for breadfruit cultivation were mostly unaffected.  Additionally, the researchers identified new suitable land where breadfruit cultivation could expand.   

As the climate continues to change, breadfruit might soon be on a table near you.

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Climate-resilient breadfruit might be the food of the future

Photo, posted August 11, 2007, courtesy of Malcolm Manners via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plant-Based Foods And CO2 Emissions | Earth Wise

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We often hear how eating locally-sourced food is a way to minimize the carbon footprint of our diet.  But from a climate impact perspective, this only has a significant impact if transportation is responsible for a large portion of a food’s final carbon footprint.  In many cases, the greenhouse gas emissions related to transportation make up only a small portion of the total emissions from food, and what we eat is far more important.

In general, beef and lamb have the biggest climate footprint per gram of protein.  Plant-based foods tend to have the smallest impact. Pork and chicken are somewhere in the middle. 

According to new research, U.S. food production could reduce its agricultural carbon footprint between 2.5% and 13.5% by embracing plant-based alternatives to beef.  The study, from researchers at Cornell University, Johns Hopkins University, and international partners, found that most of the reduction would be achieved by decreasing the number of cows needed for beef production by two to twelve million animals.  The research was recently published in the journal Lancet Planetary Health.

However, the researchers also found that acting to reduce climate change in this manner could have unintended consequences.  For example, economic models from the research team show that the growth in popularity of plant-based beef could disrupt the agricultural workforce, threatening more than 1.5 million jobs. 

But in the big picture, doing nothing will cost much more than doing something to slow climate change.  Shifting diets away from meat and other animal products and towards more plant-based foods will help shrink carbon footprints and mitigate climate change.  It’s a win-win for the planet and for human health. 

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Plant-based ‘beef’ reduces CO2 but threatens ag jobs

Photo, posted November 27, 2018, courtesy of Sarah Stierch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Hot July | Earth Wise

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At the beginning of July, the National Oceanic and Atmospheric Administration’s monthly climate outlook predicted temperatures well above average across much of the United States.  The prediction was quite correct.  Beyond that, world-wide, there were multiple heat waves, especially in Europe and Asia, where there were thousands of heat-related deaths.  On July 19th, the United Kingdom had its hottest day ever reported with a temperature over 104 degrees.

In the U.S., a series of atmospheric high-pressure systems resulted in stagnant heat domes, which resulted in more than 150 million people living under heat warnings and advisories.  Nearly every part of the continental U.S. saw above-average temperatures.  There were record-breaking triple-digit highs in several states, sometimes persisting for days.

The south-central part of the country developed a ridge of high pressure that established a heat dome that acted like a lid, trapping hot air over that area.  The extreme heat persisted throughout the month, at times expanding to the Southwest, Upper Midwest, and Southeast.

In the second half of the month, the Great Plains experienced temperatures as high as 115 degrees.  Utah and Oklahoma both broke long-standing records for the most consecutive days on which temperatures exceeded 100 degrees.  Utah saw 16 straight days over 100.

In the Pacific Northwest temperatures reached 110 degrees in Dallasport, Washington, and 114 in Medford, Oregon.  In the Northeast, Newark, New Jersey saw a record-breaking five straight days over 100 degrees.

In Albany, New York, where the average daily high temperature is 82 degrees in July, there were 10 days in the 90s, with highs of 97 on three occasions.

July was a hot month indeed.

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A July of Extremes

Photo, posted July 10, 2022, courtesy of Dominic Alves via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

North American Birds And Climate Change | Earth Wise

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Most plants and animals live in areas with specific climate conditions, such as rainfall patterns and temperature, that enable them to thrive. Any change in the climate of an area can affect the plants and animals living there, which in turn can impact the composition of the entire ecosystem.   

As such, the changing climate poses many challenges to plants and animals.  For example, appropriate climatic conditions for many species are changing.  As a result, some may even disappear altogether.  These problems can be compounded when the climate is changing in tandem with other human-caused stressors, such as land use change.

When there is increasing divergence between suitable climatic conditions for a particular species and its abundance and distribution through time, this is known as climate decoupling.

According to a new study recently published in the journal Nature Ecology & Evolution, some species of North American birds have not fully adjusted their distributions in response to climate change.  The areas where these birds live have become more decoupled from their optimal climate conditions.  Climate decoupling as a result of ongoing climate change could lead to additional stressors on many bird species and exacerbate bird population declines.

In the study, the research team analyzed data on bird population changes through time from the North American Bird Survey.  They found that at least 30 out of 114 species (or 26%) of North American birds have become less well adjusted to their climate over the last 30 years. This means that their distributions and abundances were increasingly decoupled from climate over time.

The researchers also found that the overall trend of climate decoupling shows no signs of slowing down. 

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North American birds not fully adjusting to changing climate

Photo, posted July 16, 2016, courtesy of Kelly Azar via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Space Tourism And The Climate | Earth Wise

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Space tourism is human space travel for recreational purposes.  A few well-known billionaires have taken rocket rides in recent years and at least a dozen companies are at the vanguard of what they are expecting to be a burgeoning industry.  If space tourism truly takes off – pun intended – it could be a serious threat to the climate and the environment.

Black carbon – essentially soot – is emitted when fossil fuels, including rocket fuels, are burned.  Black carbon absorbs light from the sun and releases thermal energy, making it a powerful climate warming agent.  At lower altitudes, black carbon quickly falls from the sky, remaining in the atmosphere for only a matter of days or weeks.

Rockets are another story entirely.  They dump black carbon into the stratosphere as they blast into space, and up there black carbon is 500 times worse for the climate and sticks around for several years.

A detailed study by researchers at University College London looked at the climate impact of present-day space launches compared with the potential massive expansion of launches from a large space tourism industry.

The overall result is that current space launches are not a significant source of emissions, but space launches would become incredibly significant if projections of tourist space flights proved to be true.  Currently, there are roughly 100 space launches a year world-wide.  If that number becomes thousands, the impact on the climate would be substantial.

The same researchers looked at the ozone impact of rocket launches and reached a similar conclusion.  The current impact of spaceflights is not very significant, but a massive increase in launches could have a major impact on atmospheric ozone concentrations.

Space tourism may be exciting, but it also could be very dangerous for the planet.

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Space Tourism Poses a Significant ‘Risk to the Climate’

Impact of Rocket Launch and Space Debris Air Pollutant Emissions on Stratospheric Ozone and Global Climate

Photo, posted May 30, 2020, courtesy of Daniel Oberhaus (2020) via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Better Way To Recycle Plastic | Earth Wise

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The current state of plastic recycling is not very effective.  Plastic recycling is only able to replace 15-20% of the fossil-fuel-derived raw material needed to produce society’s demand for plastic.

Researchers at Chalmers University in Sweden have now demonstrated how the carbon content in mixed waste could be used to replace all of the fossil raw materials in the production of new plastic.  In principle, their technology could completely eliminate the climate impact of plastic materials.

According to the researchers, there are enough carbon atoms in waste to meet the needs of all global plastic production.

The Chalmers process is based on thermochemical technology and involves heating waste to 1100-1500 degrees Fahrenheit.  The waste is thereby vaporized and when hydrogen is added, becomes a carbon-based substance that can replace the fossil-fuel building blocks of plastic.  The method does not require sorting the waste materials.  Different types of waste, such as old plastic products and even paper cups, with or without food residues, can be fed into the recycling reactors.  The researchers are now developing the techniques required to utilize their recycling technology in the same factories in which plastic products are currently being made from fossil oil or gas.

The principle of the process is inspired by the natural carbon cycle in which plants break down into carbon dioxide when they wither and die, and then photosynthesis uses carbon dioxide and solar energy to grow new plants.

Producing new plastics would no longer require petroleum or other fossil fuels as raw materials.  If the energy needed to drive the recycling reactors is taken from renewable sources, plastics could become the basis of a sustainable and circular economy.

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Pioneering recycling turns mixed waste into premium plastics with no climate impact

Photo, posted August 10, 2013, courtesy of Lisa Risager via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Geoengineering Research Plan | Earth Wise

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The 2022 federal appropriations act, signed into law in March, directed the Office of Science and Technology Policy to develop a cross-agency group to coordinate research on climate interventions, in partnership with NASA, the National Oceanic and Atmospheric Administration, and the Department of Energy.

The group is tasked with creating a research framework to “provide guidance on transparency, engagement, and risk management for publicly funded work on solar geoengineering research.”  The group is supposed to develop a five-year plan that will define research goals for the field, assess the potential hazards of climate interventions, and evaluate the level of federal funding required to carry out the work.

This marks the first federally coordinated effort of this kind and is especially significant because it contributes to the perception that geoengineering is an appropriate and important area of research as the climate continues to warm.

It is an understatement to say that such research is controversial.  Geoengineering has often been a taboo topic among scientists. There are significant questions about potential environmental side effects and concerns that the impact of any such efforts would be felt unevenly in different parts of the world.  There are challenging questions about global governance , including who should be able to make decisions about any potential deployment of climate interventions and what the goals of such interventions should be.

These are momentous issues to grapple with, but as the threat of climate change grows and nations continue to fail to make rapid progress on emissions, researchers, universities, and nations are increasingly motivated to seriously explore the potential effects of geoengineering approaches.  We can’t hide from the fact that these issues are going to be explored.

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The US government is developing a solar geoengineering research plan

Photo, posted June 28, 2013, courtesy of Fernando Aramburu via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Resilient Microalgae | Earth Wise

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The plight of the world’s coral reefs has been a growing environmental crisis for many years.  Coral reefs provide sustenance and income to half a billion people, are major tourist attractions, protect coastlines, and are important centers of biodiversity.   And because of the warming climate as well as other effects of human activity, more than half of the world’s coral reefs are under stress.

The primary threat is coral bleaching, which is the disruption of the symbiotic relationship between coral polyps (which are tiny animals) and the heavily pigmented microalgae that live within the coral structures and provide most of the energy for the polyps. When corals are stressed, often because water temperatures are too high, they expel the microalgae within them.  The structures then become transparent, leaving only the white skeletal corals.  Bleached corals aren’t dead, but they are at great risk of starvation and disease until and unless new symbiont algae are acquired.

A new study by scientists at Uppsala University in Sweden investigated how different species of coral symbiont algae react to temperature stress.  They discovered differences among symbiont cells that enable the prediction of how temperature stress tolerant the cells are.  Such predictive ability could provide the means to identify and select more temperature-tolerant coral symbionts that could conceivably be introduced into coral host larvae in order to make corals more robust against climate change.

The research has a ways to go, but the new tools may help coral reef monitoring and increase the speed at which reef restoring efforts can create stocks of climate-resistant symbionts.

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Climate resilient microalgae could help restore coral reefs

Photo, posted September 28, 2009, courtesy of Matt Kieffer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Living in a Carbon Bubble | Earth Wise

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The earth’s atmosphere is a little over 0.04% carbon dioxide, currently about 420 parts per million.  That’s more than it’s been in millions of years and is changing our climate.  But these levels of CO2 are not enough to directly affect people.

However, people are sensitive to the amount of carbon dioxide they are breathing.  It is actually an indoor pollutant.  High concentrations have been shown to reduce our cognitive performance, our health, and our comfort.  For example, a study in 2012 showed that performance in a variety of cognitive function tests was reduced by 12% when CO2 levels reached 1,000 parts per million and by 51% at 2,500 ppm.

How common are high levels of carbon dioxide?  Pretty common.  Offices often have CO2 levels of 600 ppm or higher, but 5% of US offices have average concentration about 1000 ppm and some conference rooms can reach 1900 ppm.  Classrooms often reach average levels above 1000 ppm.  Passenger aircraft have average levels around 1400 ppm during flight, and can peak over 4,000 ppm.  Cars with one occupant with the windows closed and the air recirculating have levels above 4,000 ppm. 

Where does it all come from?  From us.  We exhale CO2 and if we are in enclosed spaces with insufficient air circulation and ventilation, we end up living in a carbon dioxide bubble.  Most of us live with high CO2 levels – all day and every day.  It is a form of indoor pollution that has not gotten enough attention.

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I’m living in a carbon bubble. Literally.

Photo, posted October 24, 2013, courtesy of Cory W. Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Carbon Capture: Solution Or Band-Aid? | Earth Wise

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The idea of capturing the CO2 emissions from industry and locking them up is nothing new.  It’s been going on for decades in some places.  Norway’s state-owned oil company Equinor has been holing away a million tons of CO2 a year for a long time.  But overall, CCS – carbon capture and storage – has had very limited use.  As of last year, there were only about 30 large-scale projects in operation around the world, capturing only 0.1% of global emissions.

There is now growing interest in CCS and many new projects are underway.  A combination of rising carbon prices in Europe, tax breaks for CCS in the US, national net-zero targets, and the increasing need to ramp down global emissions are all driving rising CCS activities. 

While recent reports from the Intergovernmental Panel on Climate change still claim that it is possible to remain below 2 degrees Celsius of warming without using carbon capture, there is growing belief that it may be necessary given the present pace of the transition away from fossil fuels.

Two industries that together produce about 14% of global CO2 emissions are cement and steel.  These are both industries for which it is difficult to eliminate emissions regardless of the energy sources used. CCS may be the best approach to reducing their emissions.

But there is considerable pushback against CCS.  The concern is that CCS is primarily a way to delay decarbonization.  It encourages various industries to continue to use fossil fuels instead of shifting away from them.  Nonetheless, CCS no doubt has its place as part of the solution to climate change.

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Solution or Band-Aid? Carbon Capture Projects Are Moving Ahead

Photo, posted June 5, 2022, courtesy of Mark Dixon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Marine Predation And Climate Change | Earth Wise

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Climate change is taking a toll on forests, farms, freshwater resources, and economies all around the world.  But ocean ecosystems remain the center of global warming.

Despite their vast ability to absorb heat and carbon dioxide, oceans are warming.  In fact, according to scientists, the oceans have absorbed 90% of all the warming that has occurred during the past 50 years. 

The ocean’s surface layer, which is home to most marine life, takes most of this heat.  As a result, the top 2,300 feet of global ocean water has warmed approximately 1.5°F since 1901.

Well it turns out that a hotter ocean is also a hungrier ocean.  According to a new study recently published in the journal Science, researchers discovered that predator impacts in the Atlantic and Pacific oceans peak at higher temperatures.  The effects of more intense marine predation could disrupt ecosystem balances that have existed for millennia. 

An international research team led by the Smithsonian Institution and Temple University analyzed predator and prey data collected from 36 sites, running along the Atlantic and Pacific coasts from Alaska in the north to Tierra de Fuego at the tip of South America.  The research team found that, in warmer waters, predators’ more voracious appetites left outsized marks on the prey community.  Total prey biomass plunged in warmer waters when prey were left unprotected.  However, in the coldest zones, leaving prey exposed or protected made nearly no difference at all.  

As the oceans continue to warm, more intense predation will create winners and losers and could jeopardize the overall health of marine ecosystems.  

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As the ocean heats up hungrier predators take control

Photo, posted July 14, 2017, courtesy of Jonathan Chen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Methane From Thawing Permafrost | Earth Wise

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The Arctic permafrost contains a massive amount of carbon in the form of frozen soil, which contains remnants of plants and animals that died millennia ago.  Estimates are that there is 2 ½ times as much carbon trapped in this Arctic soil than there is in total in the atmosphere today.

As the Arctic warms, the permafrost is starting to thaw.  Once that happens, microbes begin to consume the previously frozen organic matter trapped in the soil.  As part of this process, the microbes produce large amounts of methane, which is an extremely potent greenhouse gas.   Thus, there continues to be great concern that wide-scale thawing of the permafrost would result in massive amounts of methane being released into the atmosphere.

A recent study in northern Sweden revealed a glimmer of hope.  The study gauged methane emissions from a swath of permafrost that thawed in the 1980s and another that thawed 10 or 15 years later. 

In the first area, as ice melted underground, water on the surface sank down into the soil.  As the surface dried out, new plants emerged that helped to keep methane emissions buried underground.

Grasses found in wet areas have straw-like structures that convey oxygen to their roots.  The straws also allow methane in the soil to escape into the atmosphere.  As the areas dry out, other plants lacking the straws can sometimes replace the grasses.  When methane can’t escape, soil bacteria break it down into carbon dioxide.

The result is that the permafrost releases only a tenth of the methane as expected.  The hope is that changes in plant cover driven by climate change may limit methane emissions from thawing permafrost.

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Thawing Permafrost In Sweden Releases Less Methane Than Feared, Study Finds

Photo, posted July 7, 2014, courtesy of NPS Climate Change Response via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Sleep | Earth Wise

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It’s no secret that our planet is heating up.  According to scientists, the warming is primarily the result of increased anthropogenic greenhouse gas emissions.  In fact, human activities are responsible for nearly all of the increase in atmospheric greenhouse gas emissions over the last 150 years. 

Climate change has already left observable effects on the planet.  For example, glaciers have shrunk, oceans have warmed, heatwaves have become more intense, and plant and animal ranges have shifted.

Most research examining the impact of climate change on human life has centered around extreme weather events and how they will affect social and economic health.  But climate change may also have a major influence on fundamental daily human activities, like sleep, that are essential to well-being.   

According to a new study recently published in the journal One Earth, scientists have found that increasing temperatures are negatively impacting human sleep around the globe.  In the study, the research team analyzed anonymized global sleep data from sleep-tracking wristbands.  The data included 7 million nightly sleep records from more than 47,000 adults across 68 countries, spanning all continents except Antarctica.     

Before the year 2100, researchers say that suboptimal temperatures may erode 50 to 58 hours of sleep per person per year.  On warm nights – where temperatures are greater than 86 degrees Fahrenheit – sleep declines an average of more than 14 minutes.  To little surprise, they found that the effect of increasing temperatures on sleep loss is substantially greater for residents in lower income countries as well as in older adults. 

Sleep is an essential restorative process integral to human health and productivity.  And it’s threatened by our changing climate. 

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Climate change likely to reduce the amount of sleep that people get per year

Photo, posted March 16, 2006, courtesy of Joe Green via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Continued Renewables Growth | Earth Wise

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In 2021, the world added a record amount of 295 gigawatts of renewable power.  According to the International Energy Agency, it is on pace to surpass that amount in 2022.

Almost half of the renewable buildout in the world is taking place in China.  In 2021, China accounted for 46% of worldwide renewable energy additions.  The EU and United States are the next two leaders.  The rapid buildup is especially impressive given the challenges developers have faced from the coronavirus pandemic, supply chain issues, and various construction delays.

Predictions are that the global total added this year will be about 320 gigawatts of renewables.  This amount is equivalent to the total power demands of Germany, which is the world’s fourth-largest economy.  Solar photovoltaics are forecast to account for 60% of the increase in global renewable capacity this year. 

The rapid growth in China and the EU are driven by strong pro-renewable policies.  In our country, wrangling over climate legislation and investigations into potential trade violations by Asian suppliers have held back our progress.  But over the next several years, offshore wind will begin to have a real impact on U.S. renewable installations.

According to the report by the International Energy Agency, renewable energy growth is likely to plateau in 2023 unless stronger climate policies are enacted. 

There are now more than 3 terawatts – that’s 3,000 gigawatts – of renewable generation capacity globally.  This compares with a little over 4,000 terawatts of fossil fuel generation.  Global renewable energy generation is currently projected to surpass that of fossil fuels by 2035.

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Following Record Growth in 2021, Renewables on Track for New High in 2022

Photo, posted October 17, 2016, courtesy of B Sarangi via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Primary Ways To Mitigate Climate Change | Earth Wise

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The most recent report issued by the Intergovernmental Panel on Climate Change states that the world must halt the increase in greenhouse gases within three years, reduce emissions by 43% in the next seven years, and eliminate them entirely by 2050.  Otherwise, there will likely be catastrophic and irreversible impacts on the climate.

With respect to achieving these reductions, the report emphasizes decarbonizing the energy sector through electrification by replacing fossil fuels anywhere and everywhere possible.  Where that isn’t yet practical – such as in shipping and aviation – the use of biofuels and hydrogen can provide a stopgap until battery technology becomes a viable alternative.

The economics of this approach continue to improve.  Since 2010, the cost of wind, solar, and batteries has declined by as much as 85%.  In many cases, costs have fallen below those of fossil fuels.  Nonetheless, the report stresses that continuing to provide national, state, and local incentives for using renewable energy is a key factor in achieving the necessary reductions.

However, reducing emissions will no longer be enough.  This is the first major IPCC report that states that man-made carbon dioxide removal strategies will be necessary to meet the goals of the Paris Climate Agreement.  So-called natural carbon storage options, like planting trees and using farming methods that sequester carbon in soil, are also important parts of the strategy.

It is up to governments, policymakers, and investors to implement the necessary changes to mitigate climate change.  There is lots of talk about it, but it will take concerted action to avoid increasingly dire consequences.

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Report highlights affordable, available ways to mitigate climate change now

Photo, posted September 8, 2007, courtesy of Kevin Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Forest Loss | Earth Wise

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India is one of the most biodiverse countries in the world.  An estimated 47,000 plant species and 89,000 animal species can be found in India, with more than 10% of each thought to be on the list of threatened species. 

India is also among the top ten countries in the world in terms of total forest coverage.  According to Indian government data, the total forest and tree cover in India is 312,000 square miles, which is 24.62% of the geographical area of the country.

However, forest loss in India has been a problem for many decades driven largely (researchers thought) by land use change.  But it turns out that climate change may also have been contributing to forest loss, and its impact is projected to become an even bigger problem in the coming years. 

In the first ever national-scale study of the relationship between forest loss and rainfall and temperature trends in India, researchers from the University of Reading in the U.K. found that climate change may have contributed to large declines in forest since the turn of the century.

The study, which was recently published in the journal Global Change Biology, found far greater forest losses were observed where and when the climate was changing most rapidly.  Decreases in rainfall had the strongest impact on forest loss. 

These findings exacerbate concerns about the already-worrying levels of deforestation in the country, and contradict official reports that have shown relatively small decreases in forest coverage in recent years. 

The research team warns that rapid changes to the climate in some regions will require targeted preservation action to reduce the risk to biodiversity in India. 

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Indian forest loss ‘worse than feared’ due to climate change

Photo, posted January 20, 2013, courtesy of Dicky Broadhurst / Frontier Official via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Atmosphere Is Thirstier | Earth Wise      

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The American West is in the throes of a two-decade-long drought.  The climate there is getting warmer and drier, which has led to increasing demand for water resources from both humans and ecosystems.  According to a new study by the Desert Research Institute and collaborators, the atmosphere across much of the U.S. is also demanding a greater share of water than it used to.

Evaporative demand, which is also called atmospheric thirst, is a measure of the potential loss of water from the earth’s surface up to the atmosphere.  It is a function of temperature, humidity, wind speed, and solar radiation.  The study, published in the Journal of Hydrometeorology, assessed trends in evaporative demand during a 40-year period from 1980-2020.

The study’s findings showed substantial increases in atmospheric thirst across much of the Western U.S. over that period, with the largest increases centered around the Rio Grande and Lower Colorado rivers.  This is important because atmospheric thirst is a persistent force in pushing Western landscapes and water supplies toward drought.

The study found that, on average, increases in temperature were responsible for 57% of the changes observed in atmospheric thirst, humidity 26%, and the other factors playing lesser roles.

For farmers and other water users, increases in atmospheric thirst mean that, in the future, more water will be required to meet existing water needs.  Crops already require more water than they did in the past and can be expected to require more water in the future.  Over time, for every drop of precipitation that falls, less and less water is likely to drain into streams, wetlands, aquifers, or other water bodies.

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New study shows robust increases in atmospheric thirst across much of U.S. during past 40 years

Photo, posted August 9, 2007, courtesy of William Clifford via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Fires Are Larger And More Frequent | Earth Wise

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According to a new study by the University of Colorado Boulder, wildfires have gotten much larger and much more frequent across the United States since the year 2000.  The rise in wildfires in recent years has been attributed to the changing climate and the new research shows that large fires have become more common and have been spreading into new areas that previously did not burn.

The researchers analyzed data from over 28,000 fires that occurred between 1984 and 2018 using satellite imagery along with detailed state and federal fire history records.

The results are that there were more fires across all regions of the contiguous U.S. from 2005 to 2018 compared to the previous 20 years.  In the West and East, fire frequency doubled, and in the Great Plains, fire frequency quadrupled.  The amount of land burned each year at least tripled in those regions.

The team discovered that the size of fire-prone areas increased in all regions of the contiguous U.S. in the 2000s, meaning that the distance between individual fires has been getting smaller than it was in previous decades and the fires have been spreading into areas that did not burn in the past.

This comprehensive study confirms what has been assumed by the media, public, and firefighting officials.  The results also align with increasing risk trends such as the growing development of natural hazard zones. Projected changes in climate, fuel, and ignitions suggest that there will be more and larger fires in the future.  More large fires plus intensifying development mean that the worst fire disasters are still to come.

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U.S. Fires Four Times Larger, Three Times More Frequent Since 2000

Photo, posted May 3, 2013, courtesy of Daria Devyatkina via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

River Of Dust | Earth Wise               

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Every year, more than 100 million tons of dust blow out of North Africa.  Strong seasonal winds lift the dust from the Sahara Desert northward.  A few times a year, the winds from the south are strong and persistent enough to drive the dust all the way to Europe.

On March 15, a large plume of Saharan dust blew out of North Africa and crossed the Mediterranean into Western Europe.  European cities were blanketed with the dust, degrading their air quality, and turning skies orange.  Alpine ski slopes were stained with the dust.

These dust events are associated with so-called atmospheric rivers that arise from storms.  Such rivers usually bring extreme moisture but can also carry dust.  Over the past 40 years, nearly 80% of atmospheric rivers over northwestern Africa have led to extreme dust events over Europe.  The March 15 event was associated with Storm Celia, a powerful system that brought strong winds, rain, sleet, hail, and snow to the Canary Islands.

Atmospheric dust plays a major role in climate and biological systems.  The dust absorbs and reflects solar energy and also fertilizes ocean ecosystems with iron and other minerals.

The climate effects of dust are complicated.  Dust can decrease the amount of sunlight reaching the surface, affect cloud formation, and decrease temperatures.  But dust also darkens the snowpack, leading to more rapid snowmelt.  A 2021 dust event resulted in a rapid melt of Alpine snow, reducing its depth by half in less than a month.

The effects of this year’s dust event are not yet known, but this atmospheric river associated with Storm Celia appeared to carry less water and more dust compared with the 2021 event.

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An Atmospheric River of Dust

Photo, posted December 2, 2019, courtesy of Catherine Poh Huay Tan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Historic Western Drought | Earth Wise

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The American Southwest has suffered from drought conditions since the year 2000.  The drought has reduced water supplies, devastated farmers and ranchers, and it has helped to fuel numerous wildfires across the region.  It has generally been considered to be worst in 500 years.

According to a recent analysis, the drought has become so severe that it has actually led to the driest two decades in at least 1,200 years and the changing climate is largely responsible.  The summer of 2021 was especially dry; about 2/3 of the West was in severe drought conditions.

Scientists at UCLA used tree ring data to gauge drought.  Based on that analysis, 2000-2021 is the driest 22-year period since 800 A.D. which is as far back as the data goes.

The study confirmed the role of temperature, more than precipitation, in driving exceptional droughts.  Precipitation levels can go up and down over time and can vary in different regions.  But the ongoing emissions of greenhouse gases into the atmosphere are causing temperatures to generally rise over time.  Warmer temperatures make the air more capable of pulling water out of the soil, out of vegetation, out of crops, and out of forests.  All of that makes drought conditions more severe.

A megadrought is generally considered to be one that is both severe and long.  But even during one, there can be wet years.  2005 was a notable one.  But there must be enough consecutive wet years to actually end a drought.

Several previous megadroughts over the past 1,200 years lasted as long as 30 years.  So, the current drought is in full swing and may go on for a long time to come.

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Web Links

How Bad Is the Western Drought? Worst in 12 Centuries, Study Finds.

Photo, posted September 25, 2021, courtesy of David Sierralupe via Flickr.

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