Summer is almost here, and you know what that means. Sun, sand and ... a watery wasteland devoid of all life? Yep, this is the time each year when a team of federal and university scientists predicts the size of the so-called dead zone that will develop in the Gulf of Mexico later in the summer. We're waiting for that official prediction, but based on federal nitrate flux data and Midwest weather patterns this spring, it seems likely that it will be bigger than usual.
The California government may have declared the drought over, but scientists say the land still has a lot of catching up to do. A new study has found that California's hardest hit areas will likely need several decades for their long-term average precipitation to recover back to normal levels.
Wildflowers north of Los Padres National Forest in early December 2016 (before the winter rains) and in late March during the wildflower super bloom. Photo credit: Planet Labs
March marked the first time in a drought-parched decade that Anza-Borrego Desert State Park—located in the Colorado Desert about two hours outside San Diego—saw 10 inches of rain. This is according to Norb Ruhmke, acting district superintendent for the Colorado Desert District. In a normal full year, he said, the Anza-Borrego desert gets six inches.
The National Oceanic and Atmospheric Administration (NOAA) reported that carbon dioxide levels in 2016 broke records for the second year in a row with an increase of 3 parts per million (ppm).
The measurements are coming from the Mauna Loa Baseline Atmospheric Observatory in Hawaii and were confirmed by NOAA's Earth System Research Laboratory in Boulder, Colorado. The numbers show that the rate of CO2 in the atmosphere is now at 405.1 ppm, the highest it has been in more than 10,000 years. Pieter Tans, lead scientist of NOAA's Global Greenhouse Gas Reference Network, said the findings are accurate and disturbing.
The Colorado River is dwindling, and climate change is officially to blame. In the first 14 years of this century, the flow declined to only four-fifths of the 20th century average, according to new research. The water lost would have been enough to supply two million people for a whole year.
Altogether, the river supplies water to seven U.S. states and two in Mexico, and 40 million people rely on it for their water. But the entire Colorado River basin has been experiencing sustained drought since 2000. And somewhere between one sixth and one half of this liquid loss can be put down to global warming, scientists said.
They publish their findings in the journal Water Resources Research. "This paper is the first to show the large role that warming temperatures are playing in reducing the flows of the Colorado River," said Jonathan Overpeck, professor of geosciences and of hydrology and atmospheric sciences at the University of Arizona.
"We're the first to make the case that warming alone could cause Colorado River flow declines of 30 percent by mid-century and over 50 percent by the end of the century if greenhouse gas emissions continue unabated."
His co-author Bradley Udall, a climate scientist at Colorado State University, said, "The future of the Colorado River is far less rosy than other recent assessments have portrayed. A clear message to water managers is that they need to plan for significantly lower river flows."
The two scientists began by looking at the drought years of 2000-2014. The river starts with precipitation in the upper regions of its drainage basin, in Wyoming, Utah, Colorado and New Mexico.
They found that in the first decade and a half of this century, average temperatures in the region were 0.9°C higher than the average for the past 105 years. This is, very roughly, the temperature by which the globe has warmed on average over the last century, under a global warming regime driven by greenhouse gases emitted from fossil fuel combustion.
But there is another factor to consider. The U.S. Southwest has a climate history characterized by intermittent megadroughts—periods of much lower rainfall over spans of 20 to 60 years.
Researchers have proposed that the risk of megadroughts is likely to increase in any climate change scenario. What actually will happen is uncertain, but the scientists are betting that as greenhouse gas emissions rise, so will the difficulties of water supply.
"Even if the precipitation does increase, our work indicates that there are likely to be drought periods as long as several decades when precipitation will still fall below normal," said Overpeck.
According to Udall, "Current planning understates the challenge that climate change poses to the water supplies in the American Southwest. My goal is to help water managers incorporate this information into their long-term planning efforts."
As nearly 200,000 Northern California residents flee to higher ground over the threat of the Oroville
Dam emergency spillway's failure Sunday night, a report has emerged that state and federal officials were warned 12 years ago that the earthen structure was already at risk of erosion.
The environmental groups said that the dam, which California built and completed in 1968, did not meet modern safety standards and urged FERC to secure the dam's emergency spillway with concrete rather than have it remain as an earthen hillside.
Should extreme rain and flooding occur, the groups warned that the excess water could overwhelm the main concrete spillway and flow into the auxiliary spillway. Too much water could cause heavy erosion and potentially unleash flooding and threaten nearby communities.
"A loss of crest control could not only cause additional damage to project lands and facilities but also cause damages and threaten lives in the protected floodplain downstream," the groups wrote.
However, FERC rejected the groups' request. Furthermore, California's Department of Water Resources and other water agencies that would have paid for the upgrades said the fix was unnecessary.
"It is important to recognize that during a rare event with the emergency spillway flowing at its design capacity, spillway operations would not affect reservoir control or endanger the dam," wrote John Onderdonk, a FERC senior civil engineer in a July 27, 2006 memo to his managers.
"The emergency spillway meets FERC's engineering guidelines for an emergency spillway," he added. "The guidelines specify that during a rare flood event, it is acceptable for the emergency spillway to sustain significant damage."
KQED describes the emergency spillway as "essentially an ungated 1,700-foot-wide notch in the rim of the reservoir ... Below an initial concrete lip, water courses over bare earth all the way to the Feather River below, scouring the incline of earth, rocks and trees."
The secondary spillway has not been needed for use in its 48-year history—until this weekend.
The water level at Lake Oroville, California's second-largest reservoir, rose to record levels of more than a foot above what's considered "full" after Northern California's particularly wet winter. The lake also receives water from the northern Sierra Nevada mountain range, which also saw heavy rainfall, CNN noted.
Although the recent rainfall has brought much-needed relief to California's six years of epic drought, the nation's tallest dam is now nearly full. Water levels at the 770-foot-tall structure were less than seven feet from the top on Friday.
While the Oroville Dam is not currently compromised, both its primary spillway and the emergency spillway have problems due to severe erosion, authorities warned.
The primary spillway has a growing hole that is 250 feet long, 170 feet wide and about 40 to 50 feet deep, according to Bill Croyle, acting director of the Department of Water Resources. Because of the main spillway's damage, water has been pouring into the emergency spillway.
Fortunately, water has stopped pouring over the dam's emergency spillway since Sunday night.
"Oroville lake levels have receded to the point that auxiliary spillway flows have stopped. DWR hopes to push over a million acre feet of water over the main spillway in the next week, clearing the way for much needed flood storage in the lake," California's Department of Water Resources said.
Still, officials are planning for the worst as the situation could yet become dangerous.
"This is not a drill. Repeat this is not a drill," the National Weather Service said Sunday, urging people living near Oroville Dam to evacuate.
A collapse of the secondary spillway could cause a "30-foot wall of water" coming out of Lake Oroville, Cal-Fire incident commander Kevin Lawson said at a Sunday night press conference.
Evacuation orders are unchanged as of Monday morning.
"Once you have damage to a structure like that it's catastrophic," Croyle said. However, he stressed that "the integrity of the dam is not impacted" by the damaged spillway.
California Gov. Jerry Brown has issued an emergency order in response to the situation.
The first all-time national heat record of 2017 was set in spectacular fashion on Thursday in Chile, where at least 12 different stations recorded a temperature in excess of the nation's previous all-time heat record—a 41.6 C (106.9 F) reading at Los Angeles on Feb. 9, 1944.
These heat waves are being driven by warmer ocean temperatures, in turn heating-up central Australia and spilling across the eastern half of the continent.
"The heat waves were likely driven by warmer sea temperatures combining with the unusual spread of a 'reservoir of hot air' that had been building in central Australia over the past several weeks," said Phil King of the Bureau of Meteorology.
The Tuesday overnight temperature for Sydney, New South Wales (NSW), a city of 4.3 million people, registered 77F. By 6 a.m. the mercury read 88F and later in the afternoon, in the western suburbs, it reached a scorching 109F.
It was the hottest sticky night in five years. Thousands of people appeared at Sydney's Bondi Beach just after sunrise to cool off.
"We're not used to seeing that many people, normally it's crickets [this early in the morning] ... but there's a lot of people in the water, it makes it difficult to see them with the sun glaring in our face," said Bondi lifeguard Andrew Reid.
Along with stifling heat, the levels of smog in Sydney are very high. This prompted the NSW Health agency to issue a warning for people with respiratory conditions like asthma. High temperatures exacerbate toxic ozone created by automobiles.
"When it's really hot and quite still, we can get a built up of some pollutants, and in this case it's ozone," said David Berry, Bureau of Meteorology forecaster. "It's from the burning of fuels and having lots of air-cons on and that sort of thing."
The latest heat wave created an extreme fire emergency elsewhere in NSW and into the Australian Capital Territory near the nation's capital city, Canberra. A fast moving wildfirecharred 5,500 acres of eucalypt forests.
While temperatures are beginning to relax in Sydney, the deadly heat wave is moving north into the state of Queensland and its capital city of Brisbane with 2.1 million people.
Last week, a vicious heat wave claimed the life of Matthew Hall, a fit and healthy 30-year-old man, while dirt bike riding along the Sunshine Coast.
"People need to be really aware that heat can affect especially the elderly and young children, but [also] people with previous medical conditions can really suffer a great deal," paramedic Lara King said. "Also young healthy fit people who don't think they have got any concerns need to be really cautious."
Last week, 200 other Queenslanders were treated for heat stroke and dehydration.
Heat waves are a silent killer. Major heatwaves have caused more deaths since 1890 than wildfires, cyclones (hurricanes), earthquakes, floods and severe storms combined.
Extreme heat increases the risk of heat illness and can also exacerbate pre-existing illnesses such as heart and kidney conditions. Children, the elderly, the disabled and outdoor workers are among those most at risk.
"There is no chance that rainfall in Australia will remain the same as the climate warms," said Professor Steve Sherwood, an author of the research from University of New South Wales.
Another report, The Heat Matches On, warned that "as Australians continue to suffer from more frequent and worsening extreme heat events, the path to tackling climate change is becoming more urgent: no new coal mines can be built, existing coal mines and coal-fired power stations must be phased out and renewable energy must be scaled up rapidly."
