Climate change accelerating death of Western forests

(Photo: Trevor Hughes, USA TODAY)

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DENVER — The iconic pine and aspen forests of the Rocky Mountains are dying off at an alarming rate thanks to conditions exacerbated by climate change — drought, insect infestations and wildfires — a new report says.

Colorado alone could lose 45% of its aspen stands over the next 45 years, says the report released Thursday by the Union of Concerned Scientists and the Rocky Mountain Climate Organization. Pine bark beetles alone have killed 46 million acres of trees across the west, an area nearly the size of Colorado.

“The wildfires, infestations and heat and drought stress are the symptoms; climate change is the underlying disease,” Jason Funk, the report’s co-author and a senior climate scientist at Union of Concerned Scientists, said in a statement.

Projections by the U.S. Forest Service that were included in the report, predict that if emissions of heat-trapping gases continue increasing at recent rates, by 2060 the area climatically suitable in the Rocky Mountains for lodgepole pine could decline by about 90%, for ponderosa pine by about 80%, for Engelmann spruce by about 66% and for Douglas fir by about 58%.

National forests and parks play a key role in the economies of Colorado, Wyoming and Montana. National parks in those states, including Yellowstone and Glacier, host about 11 million visitors annually, generating $1 billion in tourist spending, the report, Rocky Mountain Forests at Risk, said. If the landscapes significantly change, tourists may no longer visit those areas, it said.

The trees grow in different areas, depending on how cold the winters get and how warm the summers are. If climate change alters those levels, the trees won’t grow there anymore.

“So far, we have had relatively modest climate changes, but they have already jolted our forests,” said Stephen Saunders, report co-author and president of Rocky Mountain Climate Organization. “If we continue changing the climate, we may bring about much more fundamental disruption of these treasured national landscapes.”

Global Warming Negatively Affect Fisheries

Global warming has had more impact on fisheries relying on short life species such as shrimp or sardine, because it affects chlorophyll production which is vital for phytoplankton, the main food for both species. This is the conclusion of a research on the impact of global warming on the fishing resources in Mexican Pacific published on March 7, led by Ernesto A. Chávez Ortiz from the National Polytechnic Institute (IPN).

The research compared historical data regarding fisheries, available since 1950, from The Food and Agriculture Organization of the United Nations (FAO) to the data of weather variability and concluded a lot of the variabitlity in the fishing in the Mexican Pacific Ocean is caused by climate change. The sardine production increases in the 1970s, but decreased below average levels in the 1980s. While shrimp fishing increased above average but decreased in the 1990s. All these were affected by the climate change, possibly due to El Niño. In the case of shrimp, the production is linked to an input of water from the continent. A good raining season means an increase in the crustacean production, which is reduced by a dry season.

Even the benefits from global warming on fisheries previously thought to be true was proven wrong. New surface areas of the Arctic Ocean got opened up due to the earlier warming and later freezing. Besides providing easier access to oil and gas deposits, people thought it would increase the fish catch from the Arctic waters, which is currently 20 percent of the world’s catch, as warmth and light would bring nutrients to the newly open water. There are three types of algae. Ice algae are algae attaching to ice sheets and accounts for half of the living masses in Arctic waters. Phytoplankton (unattached algae) and zooplankton (tiny animals) are the bases of the food chain in the waters. All these three kinds are flourishing due to longer summer and more light in the water. These have created food sources north of the historic ground and are the base of the high hope for more catch.

There are three reasons such hope is bound for disappointment. The first reason requires an understanding of “pelagic” and “benthic”—the former means fish lives near the surface of the water and the latter means fish lives near the bottom. Benthic fish that can live in the bottom of Beaufort cannot survive in the central Arctic (depth difference is 200 meters vs. 4,000 meters). The second reason is the ocean acidification. Cold water absorbs carbon dioxide faster and the new opened ocean provides bigger absorbing area. The ocean turns carbon dioxide into carbonic acid, discouraging the formation of calcium carbonate which gives shells strength. This means less shelled organisms and less food for fish. The last and most important reason is the warming ocean may intensify the ocean stratification, defined as the tendency of seawater to separate into layers because fresh water is lighter than salt and cold water heavier than warm.

The Ocean Stratification poses danger to disrupt nutrients cycles critical to the output of the ocean. Most ocean creatures are pelagic and when they die, they sink to the bottom and are eaten by benthic creatures. The nutrients are fed back to the surface mainly through upwelling of water from the bottom, caused caused by the collision of cold and temperature water. The Arctic is home to two of the most important nutrient moving locations. Tropics water is nutrient-poor due to lack of such events. Stratification threatens this recycling system by suppressing the vertical movement of the water and is worsened by global warming. Some parts of the Arctic already showed bad stratification, limiting nutrient replenishment, especially at high latitudes which are going to get worse with global warning, therefore the fisheries will not get the benefits people expected.

By Tina Zhang

“Marine Heat Waves Have Caused ‘Almost Unprecedented’ Damage To Australian Coral”

By Katie Valentine   February 13, 2014 a

The Earth’s oceans are warming rapidly, absorbing about 90 percent of the heat created by anthropogenic climate change. Now, new research shows that this heat has caused “almost unprecedented” damage to ancient corals of the coast of Western Australia.

The research, which has yet to be published but is part of a five-year study out of the University of Western Australia, found that, in the summer of 2012-2013, a marine heat wave killed off 400-year-old porites corals, which had previously been thought to be some of the more resistant to the effects of climate change. The coral’s survival depends on algae, but that algae was destroyed by the marine heatwave, causing the coral to become bleached and more susceptible to death.

The study’s researchers told the Guardian that the damage these ancient corals suffered was a major shock.

“To see them badly damaged, or completely dead, as a result of bleachings that happened over previous years, and likely the one in 2013, was surprising,” lead scientist Russ Babcock said.

This isn’t the first time extreme heat has damaged ocean coral. The scientists said bleaching has been occurring for about 20 years, and that records show it has become more common in recent years. In 2010, corals across the world’s oceans became bleached — shedding the algae that provide them much of their food and color — due to heat stress, just the second known global bleaching of coral in history.

“It is a lot easier for oceans to heat up above the corals’ thresholds for bleaching when climate change is warming the baseline temperatures,” C. Mark Eakin of the the National Oceanic and Atmospheric Administration told the New York Times in 2010. “If you get an event like El Niño or you just get a hot summer, it’s going to be on top of the warmest temperatures we’ve ever seen.”

Coral are also threatened by ocean acidification, because more acid in the oceans means less carbonate ions, which are required for reef building. Recent research has found that rate of ocean acidification today is unprecedented, with oceans acidifying faster today than any time in the last 300 million years. That acidification affects more than just coral — increasingly acidic ocean waters can hamper shellfish larvae’s ability to grow shells, which is already hurting the shellfish industry in the U.S.

Ocean acidification has also been found to make fish hyperactive or confused, causing them to be less fearful of predators. And new research has found that ocean acidification could hamper fishes’ eyesight, leaving them vulnerable to predators.

Ocean acidification, heat and decreasing oxygen are all threats that researchers have referred to as a “deadly trio” of stressors affecting the ocean. One report from the International Programme on the State of the Oceans recommended that governments take fast action on climate change and overfishing in order to alleviate these ocean stressors.

 

Climate Change Spells Trouble for Anglers

 

New science reveals threats to prize fishing streams in warming world.

An fisherman in Montana enjoying the river.                                          Photograph by Jeff Hornbaker, Corbis

Ben Jervey for National Geographic                                                        September 18, 2013

This month, anglers who flock to Montana in search of their own authentic A River Runs Through It experience are out of luck. On September 4, the Blackfoot River, centerpiece of Norman Maclean’s beloved story (and its film adaptation that gave the entire fly-fishing industry a boost in the early 1990s), was closed to fishing by officials from Montana Fish, Wildlife, and Parks. They cited “an effort to protect fish from the stress of low stream flows.” (The river has since been reopened to fishing, but drought conditions remain.)

Such river closures have become more common in recent years, in Montana and beyond. They’ve become necessary as coldwater fish populations struggle to deal with low flows and warmer waters, symptoms that scientists link to the rising global temperatures brought about by climate change.

Last year, for instance, stretches of the Madison, Gibbons, and Firehole Rivers—all prized fishing destinations in the Yellowstone region—were closed in August. Scientists and anglers are in agreement: Climate change is already impacting the sport of fishing, and it’s likely to get a whole lot worse.

“We’ve seen huge shifts here in Montana,” said Todd Tanner, a lifelong fisherman who spends 200 to 250 days a year on the water, and who has been living in Montana for over three decades.

 “Over the last 20 or so years, we’re seeing this litany of shifts in weather patterns, and with them, a steady degradation in many of our rivers,” said Tanner. “It’s directly related to the snow going early, then to warmer springs and summers.”

 A few years ago, Tanner started the nonprofit, nonpartisan advocacy organization Conservation Hawks, and he argues that fishermen are the best equipped to see firsthand the impacts of climate change. “You can’t be out fishing for trout or bass around here and not notice the change,” he said.

A new report, published September 4 by the National Wildlife Federation (NWF)—one of the country’s largest environmental groups—backs up the anecdotal evidence and explains the variety of threats that climate change poses. Besides the closures themselves—which are typically the result of droughts and earlier than normal melt of alpine snowpack—many rivers are simply getting warmer. According to the NWF report, half of the major American rivers surveyed in a 2010 study experienced “significant warming trends over the past 50 to 100 years.”

 Fish are sensitive to temperature, explained Jack Williams, a senior scientist with the conservation group Trout Unlimited and a co-author of the NWF report, who describes a massive geographical shift in fish species already underway. “Already, native trout have been pushed around,” Williams wrote in an email.

 “Non-native species are pushing up from downstream and have sent the native trout into the higher elevation streams,” Williams explained. “Unfortunately, these streams are going to be hard hit as wildfire, drought, and increased storm intensities hit these isolated high-elevation areas hard.”

 “In the Southwest,” said Williams, “the evidence is in your face each time you survey a stream.” Small streams in New Mexico, home to Rio Grande cutthroat, Gila, and Apache trout, are particularly susceptible to temperature increases.

 Making things even worse are the wildfires, which Williams says the Southwest is seeing “at scales that we have not seen before.” Wildfires rip through trout habitat, and the increased runoff that results when the riparian areas burn eventually leads to siltation effects. “It’s a killer one-two punch in these small streams,” said Williams.