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La Niña has arrived

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After seven months of waiting following the end of the recent El Niño condition, La Niña finally showed up in the eastern Pacific Ocean in early December.

El Niño and La Niña are climate patterns in the Pacific Ocean that can affect weather worldwide.  Normally, trade winds in the Pacific blow west along the equator, taking warm water from South America towards Asia.  To replace the warm water, cold water rises from the depths.  During El Niño, trade winds weaken and warm water is pushed back east, toward the west coast of the Americas.  As a result, areas in the northern U.S. and Canada are dryer and warmer than usual.

During La Niña, trade winds are stronger than usual, pushing more warm water toward Asia.  This results in more upwelling of cooler water from the depths.  This tends to lead to drought in the southern U.S. and heavy rains and flooding in the Pacific Northwest and Canada.  During a La Niña year, winter temperatures are warmer than normal in the South and cooler than normal in the North.

According to the report published in January by NOAA, the La Niña that has arrived is not a particularly strong one.  Sea surface temperatures are only about 1.3 degrees Fahrenheit below average in the tropical Pacific.  The report also suggests that the La Niña condition may not stick around very long.

The El Niño-Southern Oscillation phenomenon adds a natural source of year-to-year variability in global temperatures.  The presence of La Niña for at least part of this year may temporarily keep the lid on rapidly climbing global temperatures.

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La Niña Is Here

Photo, posted November 23, 2011, courtesy of NASA Goddard Space Flight Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

How much energy storage is needed?

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Energy storage is a critical aspect of modern energy systems as they move towards heavy dependence on renewable sources such as solar and wind that don’t produce energy at the same rate all the time.  Excess energy generated by solar power needs to be stored for when the sun isn’t shining; excess wind energy needs to be stored for when the wind isn’t blowing.  But how much storage capacity does the energy system need to have?

Researchers at North Carolina State University have developed a model that can be used to project what a system’s storage needs would be if it were to shift entirely to renewable sources.

The model accounts for how energy production from renewable sources would change during different times of day and different times of the year.  For example, there is much more solar energy generation in the summer when the days are longer, and it is sunny more often.

There is also the issue of short-term vs. long-term energy storage.  Short-term energy storage does not refer to how long a storage device can store the energy.  It refers to how long it can provide power at its rated level.

The study focused on Italy’s energy system, which has suffered in recent years because it had difficulties in obtaining natural gas from Russia due to the invasion of Ukraine.

As the world moves increasingly towards renewable power sources, energy systems need to be able to account for the variability of those sources.  The new model offers policymakers critical information for use in energy system planning.

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Model Projects Energy Storage Needs for Fossil Fuel-Free Energy System

Photo, posted October 28, 2016, courtesy of Daxis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Species range and climate change

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The geographic range of a particular plant or animal species is the area in which it can be found during its lifetime.  The range of most species is limited by climatic factors, including temperature, precipitation, soil moisture, humidity, and wind.  Any changes in the magnitude or variability of these factors will impact the species living there. 

For example, a species sensitive to temperature may respond to a warmer climate by moving to cooler locations at higher latitudes or elevations. 

But not all species are able to move at the same speed.  According to an international research team led by scientists from the University of Massachusetts Amherst, non-native species are expanding their ranges many times faster than native species.

The researchers found that land-based plant and animal species need to be shifting their ranges by about two miles per year just to keep up with the rapid pace of the changing climate.  Marine species need to be moving about 1.7 miles per year.  However, native species are only managing to move about one mile per year on average.  

Non-native species, on the other hand, are spreading nearly 22 miles each year on their own.  Additionally, when the role humans play in assisting the spread of non-native species is factored in, the rate jumps to a whopping 1,170 miles per year.  This is more than 1,000 times faster than the rate at which native species are spreading.   

The researchers conclude that there is no chance for native species to keep up with climate change without human help.  Assisted migration needs to be on the table if native plants and animals are to survive.   

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Non-Native Plants and Animals Expanding Ranges 100 Times Faster than Native Species

Photo, posted April 10, 2011, courtesy of Bri Weldon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Storing Energy In Abandoned Mines | Earth Wise

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An international study led by researchers from Austria has developed a novel way to store energy by transporting sand into abandoned underground mines.  The technique is called Underground Gravity Energy Storage or UGES.

As the world deploys growing amounts of wind and solar energy, it is increasingly important to find ways to accessibly and efficiently store that energy to eliminate the inherent variability of the generation.  There are many ways to store energy on a short-term basis – most commonly in batteries – but cost-effective long-term storage is still in its early stages.

The UGES technique generates electricity by lowering sand into an underground mine thereby converting the potential energy of the sand into electricity by the same regenerative braking effect used in hybrid and electric cars.  The lowering sand operates a generator.   Storing energy is accomplished by lifting the sand from the mine with electric motors to an upper reservoir where it is ready for the next cycle.  By its nature, this storage technique has an indefinite duration, unlike batteries, for example, which lose energy to self-discharge.

The main components of UGES are the mineshaft, motor/generator, sand storage sites, and mining equipment.  The deeper and broader the mineshaft, the more power can be extracted from the plant, and the larger the mine, the more energy can be stored. Mines generally already have the basic infrastructure needed and are connected to the power grid.  The researchers estimate that there is global potential of 7 to 70 TWh of storage. Total global generating capacity is currently at the lower end of that range.

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Turning abandoned mines into batteries

Photo, posted October 21, 2020, courtesy of Christine Warner-Morin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Upper Atmosphere Is Cooling | Earth Wise

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The part of the atmosphere closest to the Earth’s surface has been warming since the Industrial Revolution.  This warming is associated with increasing amounts of carbon dioxide as well as other human-made chemicals that have been changing the makeup of the atmosphere. Climate change is generally thought about in terms of the lowest regions of the atmosphere – known as the troposphere – where our weather happens.

But climate models also predict that another result of the changes to the makeup of the atmosphere is that most of the atmosphere up higher will get dramatically colder.  The same gases that are warming the bottom few miles of air are cooling the much greater expanses above that extend to the edge of space.

Recent satellite data has confirmed the accuracy of these models and provide further confirmation of the human fingerprint of climate change. The natural variability of weather that complicates climate models does not play a role in the upper atmosphere.

In the higher levels of the atmosphere, the effects of increasing levels of carbon dioxide are quite different.  In the thinner air up there, the heat trapped and re-emitted by CO2 does not bump into other molecules creating warming.  Instead, it escapes to space.  Combined with the trapping of heat at lower levels, the result is a rapid cooling of the upper atmosphere.

There are potential problems associated with the cooling upper atmosphere including that it is contracting.  The result is that the crowd of manmade objects in low orbit remains there longer, and there is a potential increased degradation of the ozone layer. 

The changes we are making to the atmosphere are having significant effects from the surface of the earth to the edge of space.

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The Upper Atmosphere Is Cooling, Prompting New Climate Concerns

Photo, posted August 18, 2021, courtesy of Arek Socha via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Global Stilling | Earth Wise

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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

The Potential For Offshore Wind

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According to a new report from the International Energy Agency, offshore wind technology has vast potential for meeting our energy needs.  In total, offshore wind has the potential to generate more than 420,000 terawatt-hours of electricity each year, which is more than 18 times the global electricity demand that exists today.

Based on current policy targets and plummeting technology costs, offshore wind could increase 15-fold by 2040, becoming a $1 trillion industry and eliminating 5 to 7 billion tons of carbon dioxide emissions annually.

Offshore wind today generates just 0.3% of the world’s electricity, but its’ use is growing rapidly.  The industry has grown nearly 30% a year since 2010, and 150 new offshore projects are currently in development around the world.  The leading countries are in Europe – especially in the UK, Germany, and Denmark – but China is greatly expanding its offshore capacity and the US, India, Korea, Japan, and Canada are also expected to make large investments in offshore wind going forward.

Offshore wind is in a category of its own because it is considered a variable baseload power generation technology.  This is because the hourly variability of offshore wind is much lower than solar power or onshore wind.  Offshore wind typically fluctuates far less from hour-to-hour than the other variable energy sources.

Technology improvements and industry growth are driving steep cost reductions for offshore wind.  The cost of offshore wind is expected to be cut in half in the next five years, dropping to $60 per megawatt-hour, which is on par with solar and onshore wind and cheaper than new natural gas-fired capacity in Europe.

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Offshore Wind Has the Potential to Fulfill Global Electricity Demand 18 Times Over

Photo, posted August 9, 2016, courtesy of Lars Plougmann via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Europe Is Warming Faster Than Predicted

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A new study has found that Europe is warming faster than even climate models projected.  The number of summer days with extreme heat in Europe has tripled since the 1950s, while the number of days with extreme cold has decreased by factors of two or three depending on the region.

According to climate scientists at the Swiss Federal Institute of Technology in Zurich, the climate trends are much larger than what would come from natural variability and are a clear signal of climate change.  Extremely hot days in Europe have become hotter by an average of more than 4 degrees Fahrenheit while extremely cold days have warmed by more than 5 degrees.  The research examined data from weather stations across Europe from 1950 to 2018.  Over 90% of the stations recorded increasing temperatures over time, a percentage much too high to be purely from natural climate variability.  The results also showed that the region was warming even faster than climate models projected.

The research results come after an extremely hot summer in Europe.  Southern France hit 114.8 degrees, a new record, in June.  Germany, the Netherlands, and Belgium all recorded all-time national temperature highs.  The National Oceanic and Atmospheric Administration recently announced that July was the hottest month ever recorded.

European summers and winters will only grow hotter in the coming years as climate change accelerates.  The rapidly increasing temperatures will impact cities and people that are unprepared for them and pose real risks for residents in the coming decades.  Extreme heat is dangerous because it stresses the human body, potentially leading to heat exhaustion or heat stroke.

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Europe warming faster than expected due to climate change

Photo, posted July 30, 2011, courtesy of Marcel de Jong via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Scottish Wind Power

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Scotland is a windy country.  Most wind turbines in the European Union produce electricity at an average of 25% of their maximum rated power as a result of the variability of wind resources.  The west and northern coasts of Scotland have an average capacity of 31% or more.  Some wind farms in Scotland have achieved more than 50% capacity over the course of a year.

As of the end of last year, Scotland had more than 8 GW of installed wind power capacity.  This included 7.8 GW of onshore wind and 623 MW of offshore wind generators.  Estimates are that more than 11 GW of onshore wind could be installed in Scotland.  The total offshore potential is far greater than that but would be much more expensive.  There are multiple large-scale wind farms proposed or under construction in Scotland.

All of this growth in wind power has led to some remarkable results.  During the first half of 2019, wind turbines in Scotland produced enough electricity to power every home in the country twice over.  Scottish wind farms generated nearly 10 million megawatt-hours between January and June, which is equal to the consumption of 4.5 million homes during that period.   That is enough to take care of all of Scotland’s homes plus a large portion of northern England’s. 

Scotland has set a target of generating half of its electricity from renewable sources by 2030 and decarbonizing its energy system almost entirely by 2050.  The recent performance of its wind power installations shows that the country might be able to reach its goal much sooner than anticipated.

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Scotland’s Wind Farms Generate Enough Electricity to Power Nearly 4.5 Million Homes

Photo, posted March 27, 2017, courtesy of Ian Dick via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Economics Of Solar And Wind Power

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It is well-known that the cost of both solar and wind energy has been dropping dramatically in recent years.  That trend is largely responsible for the rapid growth of both power sources.   A recent study has revealed just how remarkable the economic progress has been.

[Read more…] about Economics Of Solar And Wind Power

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