Scientists say global warming makes storms, like Harvey, wetter

Water from Addicks Reservoir flows into neighborhoods as floodwaters from Tropical Storm Harvey rise Tuesday, Aug. 29, 2017, in Houston, in the southern US state of Texas. (AP Photo/David J. Phillip)
Updated 30 August 2017

Scientists say global warming makes storms, like Harvey, wetter

WASHINGTON: By the time the rain stops, Harvey will have dumped about 1 million gallons of water for every man, woman and child in southeastern Texas — a soggy, record-breaking glimpse of the wet and wild future global warming could bring, scientists say.
While scientists are quick to say climate change didn’t cause Harvey and that they haven’t determined yet whether the storm was made worse by global warming, they do note that warmer air and water mean wetter and possibly more intense hurricanes in the future.
“This is the kind of thing we are going to get more of,” said Princeton University climate scientist Michael Oppenheimer. “This storm should serve as warning.”
There’s a scientifically accepted method for determining if some wild weather event has the fingerprints of man-made climate change, and it involves intricate calculations. Those could take weeks or months to complete, and then even longer to be checked by other scientists.
In general, though, climate scientists agree that future storms will dump much more rain than the same size storms did in the past.
That’s because warmer air holds more water. With every degree Fahrenheit, the atmosphere can hold and then dump an additional 4 percent of water (7 percent for every degree Celsius), several scientists say.
Global warming also means warmer seas, and warm water is what fuels hurricanes.
When Harvey moved toward Texas, water in the Gulf of Mexico was nearly 2 degrees (1 degree Celsius) warmer than normal, said Weather Underground meteorology director Jeff Masters. Hurricanes need at least 79 degrees F (26 C) as fuel, and water at least that warm ran more than 300 feet (100 meters) deep in the Gulf, according to University of Miami hurricane researcher Brian McNoldy.
Several studies show that the top 1 percent of the strongest downpours are already happening much more frequently. Also, calculations done Monday by MIT meteorology professor Kerry Emanuel show that the drenching received by Rockport, Texas, used to be maybe a once-in-1,800-years event for that city, but with warmer air holding more water and changes in storm steering currents since 2010, it is now a once-every-300-years event.
There’s a lot of debate among climate scientists over what role, if any, global warming may have played in causing Harvey to stall over Texas, which was a huge factor in the catastrophic flooding. If the hurricane had moved on like a normal storm, it wouldn’t have dumped as much rain in any one spot.
Harvey stalled because it is sandwiched between two high-pressure fronts that push it in opposite directions, and those fronts are stuck.
Oppenheimer and some others theorize that there’s a connection between melting sea ice in the Arctic and changes in the jet stream and the weather patterns that make these “blocking fronts” more common. Others, like Masters, contend it’s too early to say.
University of Washington atmospheric scientist Cliff Mass said climate change is simply not powerful enough to create off-the-chart events like Harvey’s rainfall.
“You really can’t pin global warming on something this extreme. It has to be natural variability,” Mass said. “It may juice it up slightly but not create this phenomenal anomaly.”
“We’re breaking one record after another with this thing,” Mass said.
Sometime Tuesday or early Wednesday, parts of the Houston region will have broken the nearly 40-year-old US record for the heaviest rainfall from a tropical system — 48 inches (120 centimeters), set by Tropical Storm Amelia in 1978 in Texas, several meteorologists say.
Already 15 trillion gallons (57 trillion liters) of rain have fallen on a large area, and an additional 5 trillion or 6 trillion gallons are forecast by the end of Wednesday, meteorologist Ryan Maue of WeatherBell Analytics calculates. That’s enough water to fill all the NFL and Division 1 college football stadiums more than 100 times over.


In the deserts of Dubai, salmon farming thrives

Updated 21 November 2019

In the deserts of Dubai, salmon farming thrives

  • The farming of salmon in the desert is “something that no one could have imagined,” said Bader bin Mubarak
  • Fish Farm produces 10,000 to 15,000 kilos of salmon every month

DUBAI: From a control room in the middle of Dubai’s desert, Norway’s sunrises and sunsets and the cool currents of the Atlantic are recreated for the benefit of thousands of salmon raised in tanks despite searing conditions outside.
Dubai is no stranger to ambitious projects, with a no-limits approach that has seen a palm-shaped island built off its coast, and a full-scale ski slope created inside a shopping mall.
But the farming of salmon in the desert is “something that no one could have imagined,” said Bader bin Mubarak, chief executive of Fish Farm. “This is exactly what we’re doing in Dubai.”
Inside the facility, waters flow and temperatures fluctuate to create the most desirable conditions for the salmon living in four vast tanks.
“We provide for them a sunrise, sunset, tide, a strong current or a simple river current — and we have deep waters and shallow waters,” Mubarak told AFP.
Even for a country known for its extravagant ventures, building Fish Farm, located along the southern border of the emirate, was a challenging endeavour.
Salmon usually live in cold waters such as those in and off Iceland, Norway, Scotland and Alaska — which is why the farming of Atlantic salmon in a country where temperatures can reach up to 45C (113 degrees F) is a stretch to say the least.
“Creating the (right) environment for the salmon was the hardest thing we faced,” Mubarak told AFP.
“But we came up with the idea of dark water that resembles deep water, a strong current like the ocean with the same salinity and temperature of the Atlantic.”
Fish Farm bought some 40,000 fingerlings — or juvenile fish — from a hatchery in Scotland and thousands more eggs from Iceland to raise in open tanks in Dubai’s southern district of Jebel Ali.
Salmon are born in freshwater but live in salt water for much of their lives before returning to freshwater to spawn.
At their home in the United Arab Emirates, the tanks are filled with sea water that is cleaned and filtered.
Fish Farm produces 10,000 to 15,000 kilos of salmon every month.
It was established in 2013 with the support of Dubai’s Crown Prince Sheikh Hamdan bin Mohammed bin Rashid Al-Maktoum, to farm salmon and other fish including Japanese amberjack, which is used to prepare sushi.
Mubarak said that because of the technical challenge, salmon-raising remains the “greatest production” of the farm, which supplies to Dubai and the rest of the United Arab Emirates, where the population includes millions of expatriates.
“The UAE imports around 92 percent of its fish from abroad, and the goal today is to be able to fulfil (that demand) for imports internally, so that we have food security,” Mubarak said.
“In case there is an interruption, cyclone or floods, the UAE will be able to supply itself. This is the main objective.”
Another goal is to be environmentally friendly and, in a move also motivated by the high cost of electricity, Fish Farm has plans to go solar-powered.
The ecological pros and cons of farming fish on land, compared to raising them in rivers and seas, are hotly debated, as is the alternative of harvesting wild fish.
“There are animal welfare concerns about keeping fish whose natural behavior is to swim freely in seas and rivers in closed tanks,” said Jessica Sinclair Taylor, from Feedback Global, a London-based environmental group.
“There are also concerns about the energy requirements and therefore carbon emissions.”
But she said that on the plus side, land-based farming prevents water pollution in lakes or seas where salmon farms are sometimes sited, and where waste and run-off can damage marine ecosystems.
According to the Dubai Chamber of Commerce and Industry, the UAE imported 2.3 billion dirhams ($630 million, 570 million euros) of fish products, crustaceans and molluscs in 2017 and exported 280 million dirhams’ worth.
Fish Farm, the UAE’s only fish farm, hopes to meet at least 50 percent of the country’s needs within two years, said Mubarak.
In April, Fish Farm began selling its products in supermarkets. Despite its decidedly unnatural origins, the salmon is marked “100 percent organic” because of the fish feed and the absence of antibiotics in a closed environment.
“It is (more expensive), but I also think about the quality — I’ve tried different salmon before and this is less greasy and my family prefers this one,” said Katja, a German residing in Dubai.
She said that UAE is “making really great efforts to produce not only fish but vegetables and other foods locally, and I think I should really support that.”