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Coral Breeding May Help Cooler Reefs Survive
By Alister Doyle, Reuters
Corals that naturally thrive in the hottest tropical waters can be bred with cousins in cooler seas to help them survive mounting threats from global warming.
Tests of corals in warm waters on Australia's Great Barrier Reef found they were able to survive bigger temperature rises than those of an identical species in cooler seas 300 miles south, according to a University of Texas at Austin study published in the journal Science.
Coral garden at Agincourt Reef as part of the Great Barrier Reef in Australia.
Credit: Peter Nijenhuis/flickr
The study, by scientists in the United States and Australia, raises the possibility of deliberate breeding to pass on heat-tolerant genes to combat climate change, linked by almost all scientists to a build-up of man-made greenhouse gases in the atmosphere.
"Coral larvae with parents from the north, where waters were about 3.6 Fahrenheit warmer, were up to 10 times as likely to survive heat stress, compared with those with parents from the south," the scientists found.
And cross-breeding of the corals, of the Acropora millepora species common in the Pacific and Indian Oceans, brought offspring that were "significantly" better at coping with rising temperatures than the cooler southern corals, they wrote.
Corals, which are tiny stony-bodied animals, form reefs that are vital nurseries for many fish and are big draws for scuba-diving tourists.
"What I think is the most viable strategy is simply to transplant adult corals - we make a reef and let then cross with the natural corals," Mikhail Matz, a co-author at the University of Texas at Austin, told Reuters.
A United Nations report last year said that there were early warning signs that warm water corals and the Arctic, where ice is melting fast, were among the most vulnerable parts of nature and already suffering irreversible changes because of warming.
The experts cautioned that warmer waters were only one of many problems facing corals - others including pollution and an acidification of the oceans.
The fact that corals can inherit heat tolerance "is not a magic bullet that will safeguard corals from the multitude of stressors they are currently facing," Line Bay, a co-author at the Australian Institute of Marine Science, told Reuters.
The study adds to wider debate about deliberately relocating animals and plants because of climate change, despite risks for instance that they unwittingly bring diseases to their new homes.
The study is available here.
Editing by Jeremy Gaunt
Pink Salmon Risks a Double Threat of Acidification
By Alister Doyle, Reuters
Pink salmon in the Pacific Ocean face a double threat of acidification linked to greenhouse gas emissions since it slows their early growth in rivers and disrupts the chemistry of seawater.
Impacts have in the past been more studied in the seas than in fresh water. But the Canadian study found that acidification of rivers could make young pink salmon, the most abundant type in the Pacific, smaller and more vulnerable to predators by dampening their ability to smell danger.
Damage done by acidification "in fresh water in pink salmon could occur in all other salmonids", Colin Brauner, a co-author at the University of British Columbia, told Reuters. The findings were published in the journal Nature Climate Change.
Carbon dioxide, the main greenhouse gas caused by burning fossil fuels, reacts with water to produce a weak acid. That especially threatens creatures ranging from oysters to lobsters which find it harder to build protective shells.
An international study in 2013 said acidification of the oceans was happening at the fastest pace for 55 million years, because of human greenhouse gas emissions.
In the Canadian experiments, pink salmon grew on average to only about 32 mm (1.26 inches) after 10 weeks, when raised in waters with roughly double current carbon dioxide concentrations, shorter than the 34 mm (1.34 inches) in waters with current levels.
The young fish also weighed less and appeared less able to smell danger. Brauner said it was too early to say if the disruptions would last into adulthood and mean smaller commercial catches.
Scientists say is unclear how far salmon, and other marine life, may adapt or evolve in future generations to cope with rising levels of carbon dioxide.
Editing by Andrew Roche
The World’s Greenhouse Gas Emissions in One Graphic
By Alison Kanski
Carbon emissions are often considered in the future tense: the G7 aims to reduce future emissions and countries attending the Paris climate summit in December will pledge to make future carbon cuts. Amid all the future talk, the World Resources Institute (WRI) has released new information about the present — an infographic and huge database of the world’s current greenhouse gas emissions.
Based on data from the WRI’s CAIT Climate Data Explorer, the graphic shows emissions data from 2012 by country. As a whole, the world emitted 42,386 megatonnes of greenhouse gases. Here’s how that number breaks down.
The top 10 list of emitters is no surprise. It includes China, the U.S., European Union 28, India, Russia, Japan, Brazil, Indonesia, Mexico and Iran. Together, they emit twice as much as the other 175 countries in the data, accounting for 72 percent of the globe’s emissions. The top two alone, China and the U.S., account for more than one-third of the world’s emissions.
Six of the top 10 emitters are developing countries. China, India, Indonesia, Brazil, Mexico and Iran account for 38 percent of the world’s emissions. While the lowest 100 countries emit less than 3 percent of the globe’s greenhouse gases.
The energy sector makes up about 76 percent of the world’s emissions. Of the countries with energy data available, three-quarters of them attribute a majority of their emissions to energy. The projected rise of wind and solar energy in the next 25 years is likely to reduce the impact of the energy sector. Agriculture and industry are the other largest sectors that add to global emissions.
The small South Asian country Brunei has the highest per capita emissions in the world with almost 49 tons per person. Though on the world scale, the country only contributed 0.04 percent of emissions. Of the top 10 emitters, the U.S. remains the highest, with nearly 20 tons per capita in 2012.
Hawaii, Vermont Set Ambitious Examples for Renewables
June marked two huge milestones in renewable energy in the U.S., with Hawaii and Vermont both passing laws that put in place the nation’s most ambitious renewable energy goals.
Electricity generation is the nation’s largest emitter of climate-changing greenhouse gases, leading many states to set goals for how much of their power should come from low-carbon renewable energy. Today, 29 states have laws mandating a certain portion of their power to be generated from renewables as a way to combat climate change, but none have gone so far as Hawaii and Vermont.
Vermont set a new renewable energy goal in June, requiring 75 percent of the state's electricity to come from renewables by 2032.
When Hawaii Gov. David Ige signed the state’s renewable energy bill into law on June 8, the Aloha State became the first in the U.S. to mandate all of its electricity come from renewables. The goal must be met by 2045 not only as a way to reduce Hawaii’s contribution to greenhouse gas emissions, but also to reduce the cost of the state’s electricity.
Vermont followed Hawaii on June 11 with what may be an even more ambitious goal — to generate 75 percent of the state’s electricity from renewables by 2032, with 55 percent coming from renewables by 2017, less than two years from now.
Overall, the U.S. is a mosaic of commitments to renewable energy. More than half the states have some goal to boost renewables as a way to shrink their carbon footprints. California, Maine and New York, for instance, each have a mandate for at least 30 percent of their power to come from renewables. But other states take a different tack. Kansas rescinded its renewables mandate earlier this year, turning it into a voluntary goal. States such as Florida, Idaho, Wyoming and Georgia have no renewables mandate at all.
Those states stand to learn from more ambitious states, and sometimes follow their lead when it comes to climate policy. Such was the case with Hawaii, which announced its intent to pass a 100 percent renewables mandate shortly after California Gov. Jerry Brown declared that his state should revise its renewables goal from 33 percent by 2020 to 50 percent by 2030, said Peter Shattuck, clean energy director for the Acadia Center, a Boston-based think tank focusing on energy and climate change.
“Every state doing something more ambitious fundamentally expands the realm of the possible,” he said. “I think at the highest level, what Vermont and Hawaii stand to show is how quickly renewables are becoming competitive sources of energy.”
Renewables are already a major part of how electricity is generated in both Hawaii and Vermont, which, in addition to being small in size and population, are unique in several ways.
Hawaii, isolated in the Pacific Ocean, has the nation’s highest electric power rates because it generates 93 percent of its electricity using imported crude oil brought there by ship. The high rates have spawned a rush of rooftop solar panel installations across the islands, where 12 percent of all homes have solar cells on their roofs — more than any other state.
On the opposite side of the country, Vermont is unique for different reasons. The state found itself in a bind last year after it lost 70 percent of its electric power generation when the Vermont Yankee Nuclear Power Plant shut down in December. The closure forced the state to get most of its electricity from the New England electric grid, which is powered using mostly natural gas.
Each state's renewables goals are called "renewable portfolio standards." Today, 29 states have these standards, with Hawaii and Vermont leading the country in their ambitions for the percentage of their electric power supply they must produce using renewables.
Last year, Vermont generated 27 percent of its power using the only electric power sources it has within its borders — renewables, mainly solar and hydropower. And because there are no fossil fuel-fired power plants there, Vermont is also the only state in the nation that is exempt from the Obama administration’s proposed Clean Power Plan, which is slated to regulate carbon dioxide emissions from existing power plants that use fossil fuels.
As those states strive for more renewable power generation, they have much to teach other, larger states.
“Hawaii’s experience will have great immediate relevance in Alaska and Puerto Rico — both areas with similarly unique challenges,” Tom Plant, senior policy advisor at the Center for the New Energy Economy at Colorado State University. “The role of energy storage in Hawaii will be very informative for the rest of the country as well as their ongoing revisions of the outdated utility business model that governs most utilities in the U.S.”
As Hawaii adopts more renewables, it could become a “postcard from the future” for the rest of the U.S., Plant said, referring to a statement Hawaii’s Public Utilities Commission Chair Hermina Morita made in 2014.
Hawaii will set the example for other states for how rooftop solar can expand and possibly become integrated into the electric power grid, while Vermont can show the rest of the country how transportation, home heating and electric power generation may be more significantly decarbonized, Karl Rabágo, executive director of the Pace University Energy and Climate Center in White Plains, N.Y., said.
“It’s a small state, but they’ve got a good blend of rural and urban, so they’ll have a chance to address those issues in a way that I think (other states) can learn from them,” Rabágo said.
Scorched Earth Is Big Climate Concern in Alaska Wildfires
Alaska and its neighbor to the east, Canada, have kicked off wildfire season in a major way. Blazes have raged across the northern stretches of North America, sending smoke streaming down into the Lower 48 and leaving the landscape charred.
The multitudes of fires is a glimpse of things to come as the climate warms, but blackened trees are only the most visible concern. The ground beneath them is what has some truly worried, with vast carbon reserves that could contribute to even more warming of the planet if they’re sent up in smoke.
A Blackhawk helicopters pours water on the Stetson Creek Fire near Cooper Landing, Alaska on June 17, 2015.
Credit: National Guard/flickr
This summer, a number of factors have lined up to make Alaska a tinderbox. A dry winter left little snow on the ground and record heat in May, with the state’s average temperature running 7.1°F above average, melted what little snow there was. Similarly warm conditions stretched across a large portion of western Canada in late May and set the stage for extreme wildfire conditions. Over the period of June 18-24, the Bureau of Land Management lightning network recorded more than 71,000 lightning strikes in Alaska, igniting a large swath of fires.
As the sun comes up on July, 356 wildfires are burning in western Canada and another 297 are active in Alaska. For the year-to-date, wildfires have burned 3.2 million acres in western Canada and 1.8 million acres in Alaska. Both numbers are well above the long-term average and in the case of Alaska, are in record territory for the amount of acreage burned for this time of year. Similar stories have played out in Siberia in 2013 and Canada’s Northwest Territories in 2014.
“The 2015 season here in Alaska is day by day progressing to be a truly outstanding fire year relative to our rather brief historical record of annual area burned (1950 is as far back as I feel provides rather accurate numbers),” Scott Rupp, a fire ecologist at the University of Alaska, Fairbanks, said in an email.
A recent Climate Central analysis shows that over that period, large wildfires in Alaska have essentially doubled, including a large increase since 1990. Wildfire season is 40 percent longer than it was in the 1950s, now stretching 35 days longer. Much of that can be tied to rapid warming in the northern reaches of the globe, which has warmed more than twice as fast as the rest of the planet. In the past 60 years, Alaska has warmed about 3°F with similar warming rates in northern Canada.
Studies have shown that the current rate of burn in the northern forests of the world is unprecedented in at least the last 5,000 years. That makes this start to wildfire season in the boreal forest a punctuation mark on the longer term trend of ever increasing northern wildfires, one that’s expected to continue.
“The primary driver is temperature. The warmer we get, the more fires we seem to get,” Mike Flannigan, a wildland fire expert at the University of Alberta, said. “We need a 15 percent increase in precipitation to account for the warming. Very few climate models suggest there will be an increase in precipitation to compensate for the increase in temperature. The fuels will be drier in the future and it will be easy to start the spread of fire.”
Smoke from fires in western Canada is steered south into the U.S. by the jet stream in a satellite image acquired June 29, 2015.
Click image to enlarge. Credit: NASA Earth Observatory
For all the drama of trees lighting up like matchsticks, it’s what lurks below the forest that could be a major wildcard for future warming. Large reserves of peat make up a large portion of the soil, swamps and bogs in the northern reaches of the globe. Flannigan refers to it as “legacy carbon,” an accumulation of centuries of plant matter that sequesters vast amounts of carbon from the atmosphere.
Despite covering slightly less area than tropical forests, boreal forest soil stores three times as much carbon as its tropical counterpart. They currently operate as carbon sinks, taking up more carbon than they emit each year. Wildfires could flip the script, though, turning boreal forests into sources of carbon emissions as fires burn through the vast reserves of carbon locked in the trees and soil (something already happening in California). If that happens, it could rapidly warm the climate.
“Up until about 10 years ago, the prevailing dogma was peatlands just didn’t burn,” Merritt Turetsky, an ecologist at the University of Guelph, said. “They were way too wet and fire played little to no role in these ecosystems. Over time, we’ve seen that just isn’t true.”
As warming dries out forests and precipitation patterns change, the water table is dropping in once swampy areas. That makes peat susceptible to burning and when it does catch fire, centuries’ worth of carbon can burn up in the span of a few hours if fires are intense enough.
Peat fires are also notoriously resilient, smoldering for days, weeks or even popping up again after a winter of smoldering beneath the surface. Turetsky said it’s akin to throwing a wet log in a fireplace and that she plans to use satellite data to see if fires that scorched the Northwest Territories last summer managed to smolder through the winter and re-emerge this summer.
All that is to say the early drama of this year’s fire season won’t end when the last tree burns. And what lies ahead for this season depends on the rains.
“The big mystery is what will happen with the weather for the rest of the summer. . . if late summer rains don't come this year, we have the potential to far exceed the 2004 fire season,” Rupp said.
Soaring Temps in Pacific Northwest Shattered Records
Scorching temperatures above 110°F are more often associated with the stark landscapes of places like Death Valley than the cooler reaches of the Pacific Northwest. But a suped-up heat wave has left parts of Washington feeling much more like the desert Southwest and has shattered longstanding high temperature records in many spots.
Swaths of red mark where temperatures soared in the Pacific Northwest during an unusually intense early summer heat wave.
The searing heat even broke the all-time state temperature record for the month of June, with two locations — Chief Joseph Dam and Walla Walla — both hitting 113°F on Sunday, when the event peaked, according to the National Weather Service office in Spokane.
While the skyrocketing temperatures are a marker of a particularly strong area of high pressure, such record-breaking temperatures are more likely to happen in a warming world. Summer temperatures have already increased across the U.S. in recent decades; in the Pacific Northwest they have risen by almost 0.5°F per decade since 1970.
Heat Dialed Up
This heat wave began with the development of an intense ridge of high pressure over the West. Such an event isn’t unusual in the summer and temperatures in the inland Pacific Northwest can reach much higher than the cooler coasts, but typically only go up into the 80s and 90s and usually later in the summer. The sheer strength of the ridge was largely what dialed up the temperature more than normal this time, said Andy Brown, the warning coordination meteorologist for the NWS Spokane office.
Also contributing was where the air moving over the region came from: “A lot of this hot weather had originated in the desert Southwest,” Brown said. It’s also possible that the desiccated soils of drought-stricken eastern Washington helped elevate temperatures — if the soils were instead moist, they would have used up some of the excess heat through evaporation, said Karin Bumbaco, assistant state climatologist for Washington.
“With the dry soils from this year's drought, all of the energy goes into warming the ground instead,” she said in an email.
More records falling around #InlandNorthwest. Captured the moment we hit 100 at the office. #HeatWave pic.twitter.com/oVtfBVdB1m
— NWS Spokane (@NWSSpokane) June 27, 2015
All of that heat meant that plenty of records fell across eastern Washington. Spokane saw its warmest temperatures since 1961, Brown said. “So it is a very significant heat wave.”
The heat was expected to continue through the July 4 holiday weekend, though not at the same levels as last weekend’s peak.
“We’re not going to be talking the crazy hot, record-breaking temperatures,” Brown said.
Though these searing temperatures were the result of a weather event that can naturally happen, summer temperatures in the Pacific Northwest have followed the same upward trend as most of the rest of the U.S. and the world as a whole over recent decades. These rising temperatures are fueled by the buildup of heat-trapping greenhouse gases in the atmosphere that has intensified over this same period.
In the U.S., the biggest increases in summer temperatures have been in the Southwest, where they have risen by more than 3.5°F since 1970. The Pacific Northwest has also seen substantial increases in average summer temperatures, which have gone up as much as 2.6°F over that same time.
Warming temperatures in the region are a major concern for water resources, as eastern Washington depends on its winter snowpack to supply reservoirs and streams come the warmer summer months. Exceptionally warm temperatures this past winter led to dismally low snowfall which has led to a widespread drought and amped up concerns over the wildfire season.
The hot air that has descended on the Pacific Northwest has also been particularly dry, with gusty winds that have helped fan the flames of several wildfires. The largest that firefighters are contending with in Washington is the Sleepy Hollow Fire, which has raged across nearly 3,000 acres and burned more than two dozen homes and several commercial buildings. Concerns remain high going into the July 4 weekend because of worries that people will set off fireworks. Many towns have already banned them for the holiday to try to prevent new blazes being set.
While the heat wave will eventually end, the rest of the summer is likely to remain dry for Oregon and Washington, which is bad news for drought impacts and further fire concerns.
“We’re not expecting much in the way of rainfall,” Brown said. “There’s no relief in sight for the fire season, so that’s certainly a concern.”
Study: Water Use Skyrockets as Fracking Expands
Oil and natural gas fracking, on average, uses more than 28 times the water it did 15 years ago, gulping up to 9.6 million gallons of water per well and putting farming and drinking sources at risk in arid states, especially during drought.
Those are the results of a U.S. Geological Survey study published by the American Geophysical Union, the first national-scale analysis and map of water use from hydraulic fracturing operations.
USGS map of water use from hydraulic fracturing between 2011 and 2014. One cubic meter of water is 264.172 gallons. Credit: USGS
Fracking, which was banned in New York this week because of water pollution and climate concerns, injects large quantities of sand, water and chemicals into the ground at high pressure to release trapped oil and natural gas. The process has been found to leak large amounts of methane, a potent greenhouse gas, and the resulting fossil fuels are the primary cause of climate change.
However, the natural gas produced using fracking is often considered a more climate-friendly fuel for electricity generation than coal because burning gas emits fewer greenhouse gases.
Though fracking is used to produce natural gas in less-arid regions such as Pennsylvania, many of the nation’s fracking operations occur in places where water may become scarcer in a warming world, including Texas, the Rocky Mountains and the Great Plains — regions that have been devastated by drought over the last five years.
Energy companies are using more water to frack oil and gas wells because newer technology, which allows them to find oil in more complicated geology, requires it, USGS research geologist and study co-author Mark Engle said.
The amount of water fracking uses is small compared to the water needs of farming or power plant cooling, but in areas that have little water to begin with, fracking can strain water supplies.
“The reality is there is a pretty strong constraint on the amount of fresh water available,” he said.
Though some of the water used for fracking is recycled, most of it is disposed deep underground, almost entirely removed from the water cycle and never to be used again.
The study, released Tuesday, looked at water consumption used for fracking in all kinds of oil and gas wells, including traditional wells and “unconventional” wells, which usually tap oil and gas found in deep underground shale formations which were thought too expensive and impractical to drill until about a decade ago.
The amount of water used for fracking in each well varies widely by region. In southern Illinois, an operation can use as little as 2,600 gallons of water each time fracking triggers the flow of oil or gas into a well. In West Texas’ Permian Basin surrounding Midland and Odessa, fracking uses between 264,000 and 2.6 million gallons of water each time. In Pennsylvania, Ohio, south and eastern Texas, Arkansas, northern Colorado and Montana, fracking can use more than 9 million gallons of water.
Variations in geology and the specific configuration of an oil and gas well are the biggest factors in how much water fracking consumes, the study’s lead author, USGS research engineer Tanya Gallegos, said. Natural gas wells often use more water than oil wells, especially gas wells that are horizontally drilled. In a horizontal well, the drill hole runs vertically deep underground, then turns to run roughly parallel to the surface of the earth.
The USGS study shows that some of the regions using the most water for fracking are arid regions, and the amount of water each job uses is increasing quickly. Between 2000 and 2014, the average water used to drill a horizontal natural gas well increased from 177,000 gallons to 5.1 million gallons per well — enough water to fill more than seven Olympic-sized swimming pools.
Rob Jackson, a Stanford University professor of earth system science who is unaffiliated with the study, said the USGS research is more comprehensive than other studies about the water needs of fracking and clearly shows the spiking water intensity of oil and gas drilling and fracking.
“The water use for horizontal oil and gas drilling has doubled in the past five years per well,” he said. “In wet regions like the Marcellus (in Pennsylvania), I don’t think water use is that big a deal. In dry areas it can be a big deal. The strongest effects come through increased pumping of groundwater.”
Fracking can increase demand for groundwater by up to 30 percent in some arid regions, he said. “So, I think in arid counties, for groundwater consumption, this can be a major increase.”
The U.S., Brazil and China All Set Major Climate Goals
The world got a major dose of climate clarity on Tuesday. The U.S., Brazil and China — three of the world’s top greenhouse gas emitters — all released major commitments to reduce or at least slow their greenhouse gas emissions, protect forests and ramp up their use of renewable energy.
The flurry of activity comes with five months to go until major climate talks in Paris. Those talks are considered critical for a global climate agreement and Tuesday’s news indicates a growing level of commitment to reduce emissions and the impacts of climate change.
Aerial view of the Amazon Rainforest, near Manaus, the capital of the Brazilian state of Amazonas.
The day started with a bilateral commitment between President Obama and his Brazilian counterpart, President Dilma Rousseff, on clean energy. Capping two days of discussions, the two leaders announced that their countries will aim to get 20 percent of their electricity from non-hydropower renewables by 2030. The exclusion of hydropower is notable because of it can be a major source of methane emissions.
The U.S. currently gets 13 percent of its electricity from renewables but almost half of that comes from hydropower. Brazil also relies heavily on hydropower for electricity generation, but wind is the cheapest form of new power generation capacity in Brazil. Though wind power is currently a smaller portion of Brazil’s overall energy mix, its low cost means it will likely be crucial to meeting the 2030 goal.
Beyond renewables, Brazil also agreed to restore nearly 30 million acres of forests. That’s only a portion of the 148 million acres of deforestation that have happened in Brazil since 1970, but still represents a major climate benefit given tropical forests’ ability to sequester carbon dioxide out of the atmosphere. The Amazon currently sequesters up to a quarter of all human carbon dioxide emissions.
In a case of dueling climate announcements, China also formally submitted its pledge as part of the United Nations climate process. That pledge confirms that China will peak its greenhouse gas emissions by 2030, a goal it laid out late last year in a bilateral agreement with the U.S.
But the new document reveals that China plans to reduce the intensity of its emissions by up to 65 percent, a move that could lead to a smaller emissions’ peak than previously estimated. The document clocks in at 16 pages and provides rich details about how China will meet its climate goals. That includes doubling current wind and nearly quadrupling solar power generating capacity by 2020 and implementing a national carbon market. By 2030, China plans to install as much clean electricity generating capacity as all of current U.S. generating capacity.
“It is very detailed. I think that’s terrific and is a good sign,” Erika Rosenthal, an attorney with Earthjustice’s international program, said. “When China commits to doing something, they have mechanisms to make sure that that planning comes to fruition.”
China is already the global leader in clean energy investments, with $89 billion invested in clean energy projects in 2014. A recent analysis suggests that China will see an additional $3.4 trillion in clean energy investments through 2040. Coal use also fell in 2014, the first time that's happened in 14 years, indicating that China could be on the path peaking earlier than expected.
China’s commitment is part of a larger process where each country submits its plan, dubbed an Intended Nationally Determined Contribution, for climate action to the United Nations. Those commitments are all due later this year, but adding China’s into the mix with commitments already submitted by the U.S. and the European Union means that half of the world’s greenhouse gas emissions are accounted for.
Tuesday’s three pledges cap a busy month, which has seen the Pope weigh in on climate change and some of the world’s largest oil companies ask for a price on carbon emissions. While current commitments are unlikely to keep the world from warming 2°C — the current climate goal — they do represent a step toward lowering greenhouse gas emissions.
Water Use Declining as Natural Gas Grows
Research Report by Climate Central
As the U.S. has undergone a rapid and massive shift to natural gas from coal, one benefit has gone almost entirely overlooked: the amount of water needed to cool the nation’s power plants has dropped substantially.
The widespread adoption of hydraulic fracturing (fracking) technology has led to dramatically higher natural gas production in the U.S. since 2005. The resulting drop in natural gas prices, coinciding with new EPA air quality regulations for coal-fired power plants, has led to a surge in natural gas-fired electricity generation nationwide.
This interactive is available for embed. Get the code >>
Between 2005 and 2012, coal’s share of electricity generation fell to 37 percent from 50 percent. Natural gas rose to 30 percent from 19 percent. Total electricity generation stayed roughly constant.
That shift has translated into big changes in the amount of water being withdrawn from lakes and rivers to cool power plants. And it’s an important shift as nationally, 38 percent of all water withdrawn is for power plants.
During the most recent 7-year period with reliable data, water use fell dramatically to 33 trillion gallons in 2012 from 52 trillion gallons in 2005. On average, the current natural gas power plants use four times less water per megawatt-hour generated than their coal-fired counterparts.
Click images to enlarge.
Water withdrawals for power generation dropped by more than 1.5 trillion gallons per year in Ohio, New York, and Illinois; 10 states had decreases of 1 trillion gallons or more. Electricity generated from natural gas increased 370 percent on average in those 10 states, with the largest absolute increases coming in Alabama and New York.
Some power plants are designed to be cooled by water withdrawn from a river, lake, or ocean and then returned to those waters. To protect fish and other wildlife from dramatic increases in water temperatures from the discharges, regulations limit how much the water can be warmed at the power plant before it is discharged. In hot and/or dry periods some power plants have been forced to reduce output, shut down completely, or seek exemptions from the regulations.
Water consumption in power generation refers to water withdrawn from a river, lake, or ocean but not returned to the water body from which it came. Evaporation from a cooling tower is one example. Nationally, freshwater consumed to cool power plants was about 1 trillion gallons in 2012. In contrast, freshwater withdrawals were 33 trillion gallons. Power plants without cooling towers account for most of the withdrawals. These plants use “once-through” cooling systems in which water withdrawn from a river, lake, or the sea absorbs heat as it cools the plant and is discharged back to its source before its temperature exceeds the regulated limit. Most new natural gas power plants use cooling towers and many recently retired coal plants used once-through cooling, which helps explain the drop in water withdrawals for power generation nationally.
Even with reduced power plant water usage, in 20 states, all in the eastern half of the country, water withdrawn for cooling power plants accounts for more than half of all water withdrawn for all uses in that state, including agriculture. In nine states, more than three-quarters of water goes to power plants. Power generation accounts for less than 2 percent of all water use in each of the 11 states from the Rocky Mountains to the west coast. In California, where irrigated agriculture uses vast amounts of water, power generation accounts for less then 2 tenths of 1 percent of all water used in the state.
While natural gas power plants require less water than coal or nuclear plants, fracking to produce gas typically requires 3 to 5 million gallons of water per fracked well, and significant concerns have been raised about local environmental impacts of fracking fluids that are a mix of water and chemicals. However, in terms of water quantity, fracking consumes a relatively insignificant volume of water compared to that required to cool power plants: for the 10 states that fracked the most shale gas wells in 2012, average water consumption for cooling power plants per cubic foot of natural gas burned was 30 times greater than the water consumed for fracking per cubic foot of shale gas.
The interactive above shows how water use for power generation changed, state-by-state, from 2005 to 2012. You can also explore how natural gas power generation changed in each state over the same period.
Research analysis completed by Dr. Eric Larson and Sarthak Gupta.
Kenward Talks Alaskan Wildfires With Jim Cantore
By Climate Central
Alaska Entering New Era for Wildfires Report
With more than 1 million acres of forests scorched in June, Alaska is in the midst of a blazing wildfire season. Alyson Kenward, Climate Central's research director, spoke with The Weather Channel's Jim Cantore on Monday about the current spate of wildfires and a recent Climate Central report that chronicles the troubling long-term changes to the state's fire regime. A combination of rising temperatures and dwindling spring snowpack have set Alaska up for a dramatic shift in wildfire activity. Fire season is also stretching 35 days longer compared to 60 years ago. There have been nearly twice as many large wildfires in the past two decades compared to the 1950s and 60s, including a rapidly growing number in the state's Arctic region. Unless greenhouse gas emissions are cut, the amount of area burned by wildfires is projected to double by 2050 and triple by 2100.