Saturday, December 10, 2011

NZ biodiversity to change as heat rises

From: Voxy News Engine

Scientists have been reviewing evidence of changes to New Zealand's climate. They've also been projecting future changes to New Zealand's climate, and the impact on biodiversity and marine habitats.

NIWA scientist Carolyn Lundquist will be speaking on this topic at the International Congress for Conservation Biology. The congress is being held on 8 December, at SkyCity in Auckland, with over 1500 delegates registered for the meeting. It is the first time this meeting has been held in New Zealand.

New Zealand's extensive seascape is a global hotspot for marine diversity, supporting 17,135 known species (with over 50 per cent of them unique to New Zealand), and at least 17,000 undescribed species.

Models suggest that sea-level rise and temperature increase will have impacts on biodiversity, and that the anticipated changes will impact on marine ecosystems, as well as on terrestrial and freshwater ecosystems. The average air temperature in New Zealand is projected to warm by about 2.0�C by 2090 for a mid-range greenhouse gas emission scenario. Increasing temperature is predicted to result in migration southward for marine species, and migration upwards for terrestrial species, with increased mortality during extreme weather events.

Field observations and reports from fishermen in New Zealand coastal areas show "tropical species popping up where they normally wouldn't in warmer than usual years," says Lundquist.

New Zealand's marine territory is over 3.5 million square kilometres, which is about 15 times its land area. It has complex circulation patterns, resulting from the interaction of sub-tropical and sub-Antarctic fronts and New Zealand's proximity to the strong Antarctic Circumpolar Current. Changes in sea surface temperature, location and intensity of winds, and sea-level rise, will all interact with the potential to change circulation patterns.

"No-one knows exactly what will happen to these currents following substantial changes in temperature," says Lundquist.

Oceans are expected to become more acidic globally and New Zealand waters are no exception.

Increasing atmospheric CO2 increases CO2 concentrations in the oceans. As more CO2 is absorbed by seawater, it makes the seawater more acidic. Marine animals and plants that have carbon-based skeletons will find it increasingly difficult to form hard structures as the waters become more acidic.

Ocean acidification is expected to cause declines in carbonate communities such as coral reefs, with cold-water communities predicted to decline first. "In New Zealand, key species that are likely to be affected as the ocean gets more acidic include our coastal shellfish and diverse deep-sea coral reefs, so this is not just an issue for tropical coral reefs," says Lundquist.

The IPCC sea-level rise projections range between 0.18 - 0.59 metres by the 2090s but rises of more than a metre can't be ruled out. Sea-level rise is likely to impact on coastal and estuary plant and animal life, reducing coastal habitats, changing inundation patterns, and increasing vulnerability to storm surges and tides.

"In some areas of New Zealand, our coastlines are so built up and developed that, as the sea-level goes up, there is nowhere inland for mangroves and other shallow habitats to move," says Lundquist. Climate change models have predicted significant changes in the extent of mangrove habitats in Auckland east coast estuaries for the 2050s -2090s.

Model projections suggest that there will be more extreme rainfalls, with increased average precipitation in the west of New Zealand, and reduced precipitation in the east, especially in winter and spring.

Climate change is expected to change storm conditions, altering the frequency and magnitude of storm tides and wave and swell conditions.

"This will impact the marine environment. Large storm events often result in flooding and erosion of sediments from hillsides, and these sediments are transported into estuaries and coasts, where it can smother marine communities," says Lundquist.

New Zealand's 2010 coastal policy statement emphasises the need to adapt to potential climate change effects, with emphasis on protecting coastal habitats from potentially damaging impacts.

Further research is needed to develop general principles for prediction of changes to New Zealand's terrestrial and aquatic biodiversity, which can guide decision-making.

This review of climate change impacts was driven by an initiative of the Society for Conservation Biology to review potential impacts of climate change in the Oceania region.

Thursday, December 08, 2011

NASA's Jason-1 Achieves a One-Decade Landmark

From: NASA

 

Jason-1 satellite celebrates 10 years in orbit The NASA/French Space Agency Jason-1 satellite celebrates 10 years in orbit this week, adding to a 20-year continuous satellite record of global sea level rise and monitoring the waxings and wanings of El Nino (top left) and La Nina (bottom right). Image credit: NASA/JPL Ocean Surface Topography Team

On Dec. 7, 2001, NASA and the French Space Agency Centre Nationale d'Etudes Spatiales (CNES) launched the Jason-1 satellite from Vandenberg Air Force Base, Calif., embarking on a planned three-to-five-year mission to study Earth's ocean from space. Today, Jason-1 celebrates 10 years of precisely measuring ocean surface topography. The mission continues to reveal new insights into the ocean's complicated circulation patterns, while providing a critical measure of climate change by contributing to a nearly 20-year record of global sea level monitoring from space.

Jason-1 is the successful follow-on mission to the NASA/French Space Agency's pioneering Topex/Poseidon mission, which revolutionized our understanding of the dynamics of ocean circulation and global climate from 1992 to 2006. In 2008, the meteorological agencies of the United States and Europe collaborated with NASA and CNES to launch the Ocean Surface Topography Mission/Jason-2 satellite to build upon this unprecedented long-term record of consistent, continuous global observations of Earth's ocean.

Early calibration phases of the missions allowed Topex/Poseidon and Jason-1, and now Jason-1 and Jason-2, to fly over identical ground tracks. The resulting data streams from these "tandem missions" have provided seamless coverage between the three missions, allowing scientists to observe and study both short-lived events such as hurricanes, and interannual climate phenomena such as El Nino, La Nina and the Pacific Decadal Oscillation.

Other significant science results from the mission include studies of ocean circulation; the ties between the ocean and the atmosphere; and improved global climate forecasts and predictions.

"Jason-1 extended Topex/Poseidon's record of global sea level rise, one of our most important indicators of climate change, into a second decade," said Lee-Lueng Fu, Jason-1 project scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., which manages the U.S. portion of the Jason-1 mission for NASA's Science Mission Directorate in Washington. "The altimeter-observed geographic pattern of long-term sea level change is a landmark discovery of oceanography."

The Jason missions don't collect their observations in isolation, however. A National Oceanic and Atmospheric Administration-supported ocean-profiling float project, called Argo, was created to collect observations measured directly from the ocean surface and to complement the Jason data. More recently, data from the NASA/German Aerospace Center's Gravity Recovery and Climate Experiment (Grace) mission have been combined with the altimetry data from Jason and Argo to give scientists a more complete picture of Earth's changing ocean, providing an important global observing system for sea level and ocean circulation studies.

NASA is currently working with its partners NOAA, CNES and EUMETSAT on the next mission in the series, Jason-3, projected for launch in 2014. Concepts for future missions, including Jason Continuity of Service (Jason-CS) and the Surface Water and Ocean Topography (SWOT), are currently in development.

"Jason-1 measures the ongoing rise in global sea level, which is a result of human-caused global warming," said Josh Willis, JPL oceanographer and Jason-3 project scientist. "Driven by melting ice and expanding seawater, global sea level rise has become a powerful reminder of how fast humans are changing the climate. Along with its predecessor, Topex/Poseidon, and its successor, Jason-2, Jason-1 has kept a finger on the pulse of global climate change."

For more information on Jason-1 and NASA's satellite altimetry missions, visit: http://sealevel.jpl.nasa.gov/ .

JPL is a division of the California Institute of Technology in Pasadena.

Alan Buis 818-354-0474
Jet Propulsion Laboratory, Pasadena, Calif.
Alan.buis@jpl.nasa.gov

Wednesday, December 07, 2011

Builders revise plans as higher sea levels predicted

By: Frances Bula From:  The Globe and Mail

City engineers and developers are beginning to revise building plans to allow for new projections for higher sea-level rises on the B.C. coast.

Park benches which in July would usually provide a serene place to sit and watch the placid Fraser River flow by Paddle Wheel Park, adjacent to Farrell Street, are now surrounded by the rising waters of the Fraser River which tears by in full flood. - Park benches which in July would usually provide a serene place to sit and watch the placid Fraser River flow by Paddle Wheel Park, adjacent to Farrell Street, are now surrounded by the rising waters of the Fraser River which tears by in full flood. | Dave Milne/ The Globe and Mail

Park benches which in July would usually provide a serene place to sit and watch the placid Fraser River flow by Paddle Wheel Park, adjacent to Farrell Street, are now surrounded by the rising waters of the Fraser River which tears by in full flood. Dave Milne/ The Globe and Mail

In Vancouver, the company building a significant development along the Fraser River in the southeast part of the city is planning to raise its land about two-thirds of a metre. Dikes along the river in Richmond are also being planned to go higher.

And city engineers are considering options like flood-control gates, “sacrificial” first floors, and more as they plan for a 200-year future where it's being conservatively estimated the ocean may rise at least two metres.

“We have to think about raising the land up in several areas,” said Vancouver's chief city engineer, Peter Judd, who has commissioned an extensive study to calculate exactly what new requirements the city should put in place. “You need to be able to build a floor level here so you can be confident it's not going to flooded at some point.”

Mr. Judd said he is hoping to set new guidelines by mid-2012 that will help developers and the city plan buildings, roads, sewer lines and more to be workable as the ocean rises.

Buildings are typically estimated to have a 50- to 100-year life, so buildings already up around the Vancouver shoreline will meet new guidelines as they are torn down and redeveloped.

Other coastal communities around B.C. are going through the same exercise as Vancouver, as they slowly come to grips with a report from the provincial government six months ago that projected a significantly higher sea-level rise than it had set out in earlier years.

Those cities are also working through their own assessments to figure out what the province's very general and bare-bones projection – a one-metre rise by 2100, a two-metre rise by 2200 – means for them with their different terrain near the ocean.

Those that have low, flat land near the shore or along rivers near the ocean, which can be affected by incoming tides, have the most planning to do.

For Vancouver, affected areas mean all of the land around False Creek and the False Creek Flats, a formerly marshy area filled in 100 years ago. New plans will specifically affect development on either side of the just-completed Olympic Village, and a new Concord Pacific project planned on the opposite shore.

As well, it affects all the land along the Fraser River, with immediate impacts for a massive new 10,000-resident development in the southeast corner of the city that has been years in the planning by ParkLane Homes.

ParkLane has already commissioned its own study to get exact details about the impacts, said the company's development vice-president, Norm Shearing.

“This has pushed everyone forward,” he said. “The modelling is hugely complex ... but we know we need to raise our site's habitable floor level up by 0.6 metres.”

Mr. Judd said the city lands near the Olympic Village will likely be raised well over a metre. Concord Pacific is waiting to hear the outcome of the city's study before making any decisions.

Mr. Judd said that the city's more detailed projections could go two ways. The water-level rise will likely be lower than the province's projections at shorelines that extend inland.

But he noted that the provincial projection is conservative one, significantly lower than the highest predictions.

He wouldn't be surprised if that has to be revised upward again within a few years, given the historical pattern.

“It was a pretty constant increase starting in the 1970s. But it's accelerated since the mid-1990s.”

In Richmond, the province's new guidelines came as less of a jolt because that municipality, which is essentially a delta of the Fraser River, does constant updating of its projections on sea-level rise.

“This is one more step for us in a continuum of flood-protecting planning,” said city engineer John Irving. “We already require builders to build higher in the West Cambie area, getting completely lifted up by a metre and a half.”

Around the new River Green complex being built on the river near the Olympic Oval, the city is asking the dikes to be built up to as high as 4.7 metres.

Like Vancouver, Richmond has a $200,000 study in the works to flesh out the province's study.

“Their guidelines are premature. To establish meaningful guidelines, we need to do much more detailed work.”

Mr. Irving said the toughest aspect of the new guidelines is for the smaller communities and diking associations that don't have a lot of money to do their own studies.

They need additional help from the province, as well as financial support to contribute to building up dikes.

© 2011 The Globe and Mail Inc. All Rights Reserved.

Monday, December 05, 2011

Balboa Island trying to outsmart a rising sea

By Mike Reicher, Los Angeles Times

 

City engineers say it could cost about $60 million to replace the island's aging seawalls, a project that could save streets and homes from a projected 1-foot water-level rise by 2050.

image

Newport Beach officials are focusing on the Balboa Island seawalls because they are the oldest and are publicly owned. (Don Kelsen, Los Angeles Times / December 5, 2011)

As people stroll Balboa Island's picturesque waterfront, some wonder how much one of those cozy cottages costs.
City officials think about another price tag: how much it will take to defend those homes against rising sea levels.
City engineers revealed last month that it could cost about $60 million to replace Balboa Island's aging seawalls; otherwise, residents could risk more high tides washing into their streets and homes.
The island, 4 to 8 feet above sea level, represents only a small portion of coastal communities' looming problems from climate change. Replacing all of Newport Beach's seawalls could require nearly $500 million, engineers say, although some structures could be retrofitted, so the actual price would be less.
"The costs are a worst-case situation," said City Councilman Ed Selich, who represents Balboa Island, where a projected 4-foot rise in sea level by 2100 would inundate homes. "We don't know whether those projections are going to hold over the long haul, so we have to come up with a phased approach."
Already, the city's islands flood during extreme high tides. Crews pumped water from streets last winter after an 8-foot tide, coupled with storm surges, breached the seawalls.
Officials want to extend the walls, to 10 feet from 9 feet above the average sea level, to brace for an expected 1-foot water-level rise by 2050. On Balboa Island, that could mean replacing the 1930s-era concrete barriers with steel ones or extending the current structures.
Most of the city's seawalls have begun to show "widespread cracking," a public works report says.
Replacing aging infrastructure is reason enough to act now, officials say.
Newport Beach has 17 to 18 miles of seawalls, about 4.5 miles of which are in public control and 13 miles of which are privately owned.
In the conservative city, politicians often avoid talk of climate change — especially its causes — and instead point to a demonstrated sea-level rise and its threat to real estate.
Selich said he doesn't know if climate change is "man-made or simply a long-term cycle."
"I just know that the evidence is there that [the sea] is rising," he said, "and we have the responsibility to deal with it."
Selich hopes that over the next five years the city can build up the walls on Balboa Island that are already prone to flooding.
Each new seawall would be engineered to accept a 4-foot extension, in anticipation of the 2100 scenario. City officials are relying on mid-range estimates derived from projections by the Army Corps of Engineers and other tidal studies.
"We don't want to overbuild now," said City Engineer Dave Webb, who recommends reassessing around 2050.
Officials are focusing now on Balboa Island because its walls are the oldest and publicly owned. A citywide project could require property owners to replace private seawalls — a daunting proposal that hasn't been vetted for funding or feasibility. Another idea is to require ground floors to be built at the 10-foot tide level.
"Right now we're just looking at Balboa Island," Webb said. "The money is huge."
The Balboa Island Ferry, which takes riders from the Balboa Peninsula to the island, alone could require $3.5 million to $5 million to retrofit its landings and adjacent fuel dock.
But the consequences of inaction could also be huge. Though Newport Beach hasn't projected property loss from extreme floods, a study commissioned by the California Department of Boating and Waterways found that rising sea levels could cost beach cities hundreds of millions of dollars in lost tourism and tax revenue.
To fund the fortifications, officials have identified a few federal and state grants. But they say money also would have to come from other sources, such as city funds and homeowner assessments.
"At some point, the property owners are going to have to kick in," Selich said.
That might be a challenge, especially for homeowners like Donna DiBari, whose home hasn't flooded recently. In 1985, her first year on Balboa Island, DiBari saw extensive flooding, but her seawall hasn't been breached much since then.
"If we felt it — if the water kept going into my garage — then I'd be afraid," she said.
Fear isn't motivating Webb. He says the seawalls have to be replaced anyway, so the city is using the latest science to choose a height.
"We're trying to do some advance work here," Webb said. "We don't want to wait until we have a problem."
mike.reicher@latimes.com

Copyright © 2011, Los Angeles Times