Tag Archives: weather

Op-Ed: It’s a fact: climate change made Hurricane Harvey more deadly 

Michael Mann, THE GUARDIAN

What can we say about the role of climate change in the unprecedented disaster that is unfolding in Houston with Hurricane Harvey? There are certain climate change-related factors that we can, with great confidence, say worsened the flooding. What we know so far about tropical storm Harvey Read more Sea level rise attributable to climate change – some of which is due to coastal subsidence caused by human disturbance such as oil drilling – is more than half a foot (15cm) over the past few decades (see here for a decent discussion). That means the storm surge was half a foot higher than it would have been just decades ago, meaning far more flooding and destruction.

In addition to that, sea surface temperatures in the region have risen about 0.5C (close to 1F) over the past few decades from roughly 30C (86F) to 30.5C (87F), which contributed to the very warm sea surface temperatures (30.5-31C, or 87-88F).

There is a simple thermodynamic relationship known as the Clausius-Clapeyron equation that tells us there is a roughly 3% increase in average atmospheric moisture content for each 0.5C of warming. Sea surface temperatures in the area where Harvey intensified were 0.5-1C warmer than current-day average temperatures, which translates to 1-1.5C warmer than “average” temperatures a few decades ago. That means 3-5% more moisture in the atmosphere.

That large amount of moisture creates the potential for much greater rainfalls and greater flooding. The combination of coastal flooding and heavy rainfall is responsible for the devastating flooding that Houston is experiencing.

Not only are the surface waters of the Gulf of Mexico unusually warm right now, but there is a deep layer of warm water that Harvey was able to feed upon when it intensified at near record pace as it neared the coast. Human-caused warming is penetrating down into the ocean. It’s creating deeper layers of warm water in the Gulf and elsewhere.

Read more at: It’s a fact: climate change made Hurricane Harvey more deadly | Michael E Mann | Opinion | The Guardian

Filed under Climate Change & Energy

Scientists fear Trump will supress new climate report

Lisa Friedman, THE NEW YORK TIMES

Read the draft of the Climate Change Report.

The average temperature in the United States has risen rapidly and drastically since 1980, and recent decades have been the warmest of the past 1,500 years, according to a sweeping federal climate change report awaiting approval by the Trump administration.

The draft report by scientists from 13 federal agencies, which has not yet been made public, concludes that Americans are feeling the effects of climate change right now. It directly contradicts claims by President Trump and members of his cabinet who say that the human contribution to climate change is uncertain, and that the ability to predict the effects is limited.

“Evidence for a changing climate abounds, from the top of the atmosphere to the depths of the oceans,” a draft of the report states. A copy of it was obtained by The New York Times.

The authors note that thousands of studies, conducted by tens of thousands of scientists, have documented climate changes on land and in the air. “Many lines of evidence demonstrate that human activities, especially emissions of greenhouse (heat-trapping) gases, are primarily responsible for recent observed climate change,” they wrote.

The report was completed this year and is a special science section of the National Climate Assessment, which is congressionally mandated every four years. The National Academy of Sciences has signed off on the draft report, and the authors are awaiting permission from the Trump administration to release it.

Read more at: Scientists Fear Trump Will Dismiss Blunt Climate Report – The New York Times

Filed under Climate Change & Energy

Sonoma County’s Gravenstein apple crop a mixed bag this year

Robert Digitale, THE PRESS DEMOCRAT

Apple farmer Lee Walker also has noticed more falling fruit this year. He and other farmers speculate the numerous hot days this summer may be partly to blame.

“Normally we get maybe one” hot spell per summer that hovers around 100 degrees, he said. However, this year there have been several heat waves.

The Gravenstein apple crop is a mixed bag this season for Sonoma County farmers.

As they gear up for the typically short harvest, some apple farmers said they expect a good crop of the red-and-green streaked fruit, an iconic but fairly delicate local variety and the earliest to be picked in the orchards around Sebastopol.

But others report their gravs suffered from long spring rains during bloom or from prolonged heat this summer.

Joe Dutton, an apple and grape grower outside Graton, said that this season, one block of trees in an orchard shows plenty of fruit, while another nearby block didn’t fare as well.

“The microclimates are for sure showing what they can do,” said Dutton, who farms grapes and apples at Dutton Ranch with his brother, Steve Dutton. Joe Dutton called the farm’s Gravenstein crop “spotty” and advised consumers to get fresh gravs soon because “they will not last long.”

The west county is gearing up for apple season, where for decades the Gravenstein has been a staple in juices and pies.

Apples remain one of the county’s million-dollar crops, though the value lags far behind such areas as livestock, nursery products, eggs, dairy and wine. Last year, the Gravenstein crop amounted to nearly $1.6 million, while the value of late variety apples, such as Jonathans and Golden Delicious, totaled almost $3.9 million.

Read more at: Sonoma County’s Gravenstein apple crop a mixed bag this year | The Press Democrat

Filed under Agriculture/Food System, Climate Change & Energy

It’s like it never left: Another El Niño may be on the way

Henry Fountain, THE NEW YORK TIMES

Less than a year after one of the strongest El Niños on record, forecasters see an increasing possibility that another will begin later this year.

There is no word yet on how strong a new El Niño might be, but even a mild one could affect weather patterns around the world. Among the potential effects are wetter conditions across the southern United States, including Southern California; a drier Midwest; and drought in parts of Africa, Asia and South America.

An El Niño can also influence global temperatures that are already rising because of greenhouse gas emissions. The strong El Niño of 2015-16 contributed to those years’ being the two warmest on record.

An El Niño occurs when warm water in the equatorial Pacific shifts, creating an immense warm zone in the central and eastern Pacific. This adds heat and moisture to the air, releasing energy that affects the high-altitude winds known as jet streams that circle the planet.

Read more at: It’s Like It Never Left: Another El Niño May Be on the Way – The New York Times

Filed under Climate Change & Energy

Wet winter banishes Northern California drought, fills North Bay reservoirs

Nick Rahaim, THE PRESS DEMOCRAT

Rain storms this winter have swelled water in Lake Sonoma to near-record levels, submerging once-dry boat ramps, repeatedly flooding the dockside marina and banishing the bath tub rings that for years were a telltale sign of the state’s prolonged and withering drought.

Only in the El Niño winter of 1995 did the reservoir in northwestern Sonoma County — the North Bay’s largest, created behind Warm Springs Dam in 1982 — rise higher than it did early this week, when it topped 125 percent of its capacity, with enough water to cover 300,000 football fields 1-foot-deep. The bountiful supply is more than twice the volume of water held in the lake in November 2014, amid the five-year drought that forced conservation of drinking water and cut into recreational opportunities for boaters and others.

The outlook now could hardly be more different.

With torrents of runoff coming into Lake Sonoma and Lake Mendocino, the Russian River’s smaller reservoir to the north, dam managers are now cranking up their releases to preserve room for additional storms. Another front is expected to arrive Wednesday night.

“We’re releasing a lot of water like we’re supposed to — we need to keep space open for the next big storm,” said Mike Dillabough, chief of Operations and Readiness division for the United States Army Corps of Engineers’ San Francisco Division. “But we’re told it’s burgeoning on a record year.”

Read more at: Wet winter banishes Northern California drought, fills North Bay reservoirs | The Press Democrat

Filed under Water

California drought is made worse by global warming, scientists say 

Justin Gillis, THE NEW YORK TIMES

Global warming caused by human emissions has most likely intensified the drought in California by 15 to 20 percent, scientists said on Thursday, warning that future dry spells in the state are almost certain to be worse than this one as the world continues to heat up.

Even though the findings suggest that the drought is primarily a consequence of natural climate variability, the scientists added that the likelihood of any drought becoming acute is rising because of climate change. The odds of California suffering droughts at the far end of the scale, like the current one that began in 2012, have roughly doubled over the past century, they said.

“This would be a drought no matter what,” said A. Park Williams, a climate scientist at the Lamont-Doherty Earth Observatory of Columbia University and the lead author of a paper published by the journal Geophysical Research Letters. “It would be a fairly bad drought no matter what. But it’s definitely made worse by global warming.”

The National Oceanic and Atmospheric Administration also reported Thursday that global temperatures in July had been the hottest for any month since record-keeping began in 1880, and that the first seven months of 2015 had also been the hottest such period ever. Heat waves on several continents this summer have killed thousands of people.

Read more at: California Drought Is Made Worse by Global Warming, Scientists Say – The New York Times

Filed under Climate Change & Energy, Water

Don’t count on El Niño, rain could miss Northern California altogether

CBS SF-BAY-AREA

Don’t count on El Niño to end California’s historic drought. That’s the warning from one of California’s top water officials.

Felicia Marcus, chair of the State Water Resources Control Board, said El Niño could soak Los Angeles and miss Northern California altogether.

“Don’t count on El Niño,” said Marcus. “If we get an El Niño, worry about flooding and property damage, loss of life and all that.”

Marcus worries Northern Californians will back off their record-setting conservation because they keep hearing El Niño is coming to the rescue.

“We’ll take the water if it comes,” said Marcus. “I just don’t want folks to think they don’t have to conserve because El Niño will save us, or to not understand that a strong El Niño has a downside.”

Marquez says conservation remains the key. Fortunately, Californians exceeded the state’s water-saving targets in June. Some customers cut their consumption by more than 40 percent. She predicts the July statistics will be even better “because people get it, and their water agencies are helping them.”

Still, Marquez is optimistic Californians will weather this drought whether El Niño delivers or not. People just need to keep conserving.

“This is not your garden variety drought — not your mother’s drought, not your grandmother’s drought,” warns Marcus. “This is not only the drought of the century, this could be the drought of many millennia.”

Source: Don’t Count On El Niño, Rain Could Miss Northern California Altogether

Filed under Sustainable Living, Water

Strong El Niño weather pattern spurs hope of drenching California winter

Bill Lindelof, THE SACRAMENTO BEE

While nobody is saying the four-year drought will soon be over, a federal report indicates that an El Niño weather pattern is gaining in strength – making the chances better that this winter will be a wet one.

“If you are a gambler, this is giving you some information in terms of what the seasonal rainfall might be,” said Tom Di Liberto, meteorologist for the federal Climate Prediction Center. “But with weather there is no guarantee. El Niño is only one of many things that could impact California’s rainy season.”

With all that said, Di Liberto said that the development of a strong El Niño is good news in terms of rainfall.A strong El Niño such as the one developing this year is usually associated with powerful winter storms, much like the very wet winter of 1997-98 when flooding and landslides occurred across broad stretches of Northern California.

In March, forecasters declared a weak El Niño had developed. On Thursday, the National Oceanic and Atmospheric Administration announced El Niño is strengthening.

Specifically, forecasters believe that there is a greater than 90 percent chance that El Niño will continue through next winter in the Northern Hemisphere, and around an 80 percent chance it will last into early spring 2016.

In its report, the U.S. Climate Prediction Center noted that sea surface temperatures are warming, a sign that the El Niño weather pattern is strengthening. While El Niño is no guarantee the four-year drought will be broken, robust El Niños often bring strong winter storms.

“Often, when we have a strong El Niño, you tend to see above-average precipitation across parts of California,” Di Liberto said. “That is good. It’s been very, very dry in California over the last four years. It’s important to monitor to see whether we continue to see a strengthening El Niño.”

El Niño is a large-scale ocean-atmosphere phenomenon linked to the warming of the sea surface in the central and east central equatorial Pacific Ocean. An El Niño is detected by satellites and buoys.

“We will have to see what happens as we go forward but what we see now in the Pacific Ocean and the way the (computer) models are predicting it, we are expecting a strong (El Niño) event as we get into the late fall and winter,” Di Liberto said.

Source: Strong El Nino weather pattern spurs hope of drenching California winter | The Sacramento Bee

Filed under Water

Models and experts lean toward strong El Niño forecast for the fall

Jason Samenow, THE WASHINGTON POST

El Nino is here, strengthening, and the buzz is growing that it could become a “big one” by the fall or winter. The global consequences of a powerhouse El Nino would be enormous. But just how likely is that? Both computer model and human forecasters suggest it’s a very real possibility, at least a 50-50 one. Computer models are particularly aggressive in their forecasts.

Five ways a strong El Nino could affect our weather

Average of dynamic computer models (yellow curve) forecast a strong El Nino event by the fall. (International Research Institute for Climate and Society, adapted by CWG)

Average of dynamic computer models (yellow curve) forecast a strong El Nino event by the fall. (International Research Institute for Climate and Society, adapted by CWG)

The models forecasts compiled by the International Research Institute (IRI) for Climate and Society, based at Columbia University, on average predict a strong event by the fall.

The Australia Bureau of Meteorology (BOM) notes its computer model forecasts, on average, call for a very strong event.

Very strong or “super El Nino” events fall at the most intense end of the El Nino spectrum, which starts at weak and then steps up through moderate and strong levels.  Only two events in modern records have ever achieved “very strong” intensity were the events in 1982-1983 and 1997-1998, which was the strongest on record. The 1997-1998 event is well-known for contributing to torrents of rain in California, leading to $550 million in damages.

(Note that El Nino events earn their strength designations according to how much warmer than normal ocean temperatures are in a section of the east central tropical Pacific, known as Nino region 3.4. A weak event has ocean temperatures 0.5-0.9 C warmer than average, a moderate event 1.0-1.4 C warmer than average, a strong event 1.5-1.9 C warmer than average and very strong more than 2 C above average.)

Some forecasters view the models with skepticism. Last year at this time, many models were predicting a weak to moderate El Nino event for the fall which failed to materialize.

But others feel the models are onto something, pointing out that this year, unlike last year, El Nino is already firmly established and on the cusp of moderate strength.

Read more at: Models and experts lean toward strong El Nino forecast for the fall – The Washington Post

Filed under Water

Sonoma County gets high marks for good air 

Guy Kovner, THE PRESS DEMOCRAT

Sonoma County once again got straight-As on the American Lung Association’s latest air quality report card, which also cited California’s prolonged drought as a factor in fouling the state’s skies.

For the second year in a row, the county went without a single day of ozone or particle pollution exceeding federal standards, according to State of the Air 2015, the lung association’s annual report released Wednesday. Much of the credit can go to the breezy weather that typically blows away bad air.

Only three other coastal counties — Mendocino, Humboldt and Monterey — matched that perfect score, while Lake County came close with a single day of high ozone pollution, just as it did in last year’s report.

Read more via: Sonoma County gets high marks for good air | The Press Democrat

Filed under Air, Transportation