By David Fogarty

(Reuters) – From record floods to crippling droughts and wildfires, a natural swing in Pacific Ocean temperatures can trigger climate chaos around the globe.

The El Nino ocean-weather pattern is linked to droughts in Australia and floods in parts of South America, while its sibling La Nina causes the opposite, with the two phenomena occurring at irregular intervals.

A powerful La Nina triggered record floods in eastern Australia in 2011 and has been blamed for the withering drought in Texas and severe dry spells in South America, hitting corn and soy crops.

Forecasters say an El Nino might develop later in the year.

Following are some questions and answers on El Nino and La Nina and their billion-dollar impacts on economies.

WHAT IS EL NINO?

SINGAPORE, April 27 (Reuters) – Major Asian buyers led by China are set to approve genetically modified corn within the next three to five years to give yields a boost as growing demand for meat drives greater consumption of the staple, the world’s top agrochemicals company said.

Changing diets and greater wealth are pushing up demand for corn, a key source of animal feed, in Asia. But local yields are not enough to meet demand, triggering imports and inflation.

This is accelerating the push to improve yields and food security, said Davor Pisk, chief operating officer for Basel-based Syngenta (SYNN.VX: Quote, Profile, Research), one the world’s top seed firms.

China’s corn yields are half those of the United States, and the world’s second biggest consumer and grower of corn is becoming increasingly reliant on imports. Domestic firms are likely to introduce GM corn by 2017 or earlier.

“I would personally expect that within the next 4 to 5 years we will see GM corn commercialised in China,” Pisk told Reuters in an interview in Singapore.

He said the government wanted to be certain there was public confidence in GM first as well as ensuring local firms had the technology to pioneer GM crops.

Other countries held strong sales potential for GM seeds and chemical products that kill weeds and pests, Hardeep Grewal, Syngenta’s head of corn marketing for the Asia-Pacific, said in a separate interview in Singapore.

SINGAPORE, April 27 (Reuters) – After years of wrenching debate, a carbon tax on Australian industry starts in July, but instead of bringing much-needed investment certainty, the scheme is delivering the opposite.

Much of Australian’s power sector is struggling to access cheap, long-term financing on worries over the future of the carbon tax scheme, which is meant to provide a long-term price signal to encourage industries to cut their emissions.

Instead, political uncertainty is undermining more than $200 billion of investment the government says is needed to clean-up the nation’s ageing coal-fired power sector.

The opposition, which is well ahead in the polls, has vowed to scrap the carbon tax if it wins power.

“Because it’s a tax on power and a tax on transport, it will drive up every single price in our economy,” Opposition leader Tony Abbott said in a speech last week.

Most voters are also opposed to the scheme, which could cost Prime Minister Julia Gillard an election slated for 2013.

Opposition-run states, such as Victoria, Queensland and New South Wales, are also pushing back on climate programmes, further clouding the regulatory picture and hampering refinancing of existing power plants and funding of new ones.

SINGAPORE (Reuters) – Scientists have detected a clear change in salinity of the world’s oceans and have found that the cycle that drives rainfall and evaporation has intensified more than thought because of global warming.

The finding published on Friday helps refine estimates of how different parts of the globe will be affected by increased rainfall or more intense droughts as the planet heats up, affecting crops, water supplies and flood defenses.

Scientists led by Paul Durack of the Lawrence Livermore National Laboratory reported clear changes in salinity patterns across the world’s oceans between 1950 and 2000.

Oceans cover 71 percent of the planet’s surface and store 97 percent of the world’s water and are therefore the main source of moisture in the atmosphere through evaporation.

The global cycle of rainfall and evaporation of water from the land and surface of the ocean comprise the global water cycle, with some areas such as the tropics naturally wetter and others, such as large parts of Australia, the United States or northern Africa, drier.

Some ocean regions are saltier, meaning less rainfall and others are fresher, meaning high rainfall, making salinity measurements a good way to measure changes in rainfall patterns.

Durack and team, in a study published in the journal Science, found that the water cycle intensified 4 percent from 1950-2000, twice as much as projected by climate models.

SINGAPORE, April 17 (Reuters) – An Australian firm has frozen development of a controversial A$1.2 billion ($1.23 billion) brown coal-gas hybrid power plant after a ruling by a tribunal effectively delayed construction, putting the future of the project in doubt.

Energy technology firm HRL, one of a number of companies trying to develop clean-coal power plants, said it had frozen design and pre-construction work on a proposed 600-megawatt plant in the southern state of Victoria.

It made the decision after a state tribunal ruling last month linked a go-ahead for the project to Australian government efforts to shut down some of the power industry’s biggest greenhouse gas emitters under a programme known as “contract for closure”.

“As a consequence of the imposition of the condition, there is considerable uncertainty as to the date on which construction of the project could commence, if at all if there is no contracts for closure,” HRL said in a statement.

HRL aims to cut greenhouse gas emissions from using brown coal for power generation, but its plant has been criticised by green groups who say emissions would still be higher than more efficient gas-fired power plants. They also favour greater use of renewable energy such as wind and solar.

The firm has won pledged funding of $100 million from the Australian government and $50 million from the state government in Victoria, which has the world’s second-largest reserves of brown coal. However, the latest delay means it could miss out on the $100 million federal grant.

A HRL spokeswoman confirmed the project, in development for more than 5 years, had been frozen. The plant had been slated for construction in Morwell, in the Latrobe Valley east of Melbourne, the state capital.

SINGAPORE (Reuters) – The powerful undersea earthquake off the Indonesian island of Sumatra this week was a once in 2,000 years event, and although it resulted in only a few deaths, it increases the risks of a killer quake in the region, a leading seismologist said.

Wednesday’s 8.6 magnitude quake and a powerful aftershock were “strike-slip” quakes and the largest of that type recorded, Kerry Sieh, director of the Earth Observatory of Singapore, told Reuters.

“It’s a really an exceptionally large and rare event,” he said.

“Besides it being the biggest strike-slip earthquake ever recorded, the aftershock is the second biggest as far as we can tell,” said Sieh, who has studied the seismically active, and deadly, fault zones around Sumatra for years.

Strike-slip quakes involve the horizontal movement of colliding earth plates, and are typically less powerful than those where there is vertical movement. They are also less likely to trigger big tsunamis, or tidal waves.

A magnitude 9.1 quake in roughly the same region on Boxing Day in 2004 decimated Aceh province on Sumatra and killed over 230,000 people in 13 countries around the Indian Ocean.

Sumatra, the westernmost island in the sprawling Indonesian archipelago, has a history of powerful quakes and tsunamis, most triggered by an offshore zone along its entire length, where the Indian-Australian tectonic plate is forced under the Eurasian plate.

By David Fogarty and Deborah Zabarenko

(Reuters) – A future on Earth of more extreme weather and rising seas will require better planning for natural disasters to save lives and limit deepening economic losses, the United Nations said on Wednesday in a major report on the effects of climate change.

The U.N. climate panel said all nations will be vulnerable to the expected increase in heat waves, more intense rains and floods and a probable rise in the intensity of droughts.

Aimed largely at policymakers, the report by the Intergovernmental Panel on Climate Change makes clear nations need to act now, because increasingly extreme weather is already a trend.

The need for action has become more acute as a growing human population puts more people and more assets in the path of disaster, raising economic risk, the report said. The report’s title made the point: “Managing the risks of extreme events and disasters to advance climate change adaptation.”

Asia was most vulnerable to potential disasters, with East Asia and the Pacific facing the highest adaptation costs.

The 594-page report, with authors from 62 countries, is the world body’s most up-to-date assessment of climate change risks. Its general message is that enough is known about these risks for policymakers to start making decisions about how to deal with them.

SINGAPORE, March 14 (Reuters) – Australia, one of the world’s top mining and agricultural nations, faces a quickening pace of climate change, according to a snapshot of the nation’s weather, forcing farmers to alter cropping strategies and miners to cope with more intense floods.

The government report released on Wednesday confirms the changing trends in rainfall and warmer temperatures across Australia, to which farmers are adapting by growing new crop varieties and adjusting planting times.

Coal and iron ore miners are building bigger holding dams for flood waters, and strenthening road and rail infrastructure, while coastal communities are being told to prepare for rising sea levels.

The report, compiled by the Bureau of Meteorology and the Commonwealth Scientific and Industrial Research Organisation (CSIRO), looks at long-term climate trends in Australia. Its release comes after 18 months of record rains in the country’s east, triggering floods that ended a devastating drought.

Australia is getting hotter, the pace of sea level rise quickening, the oceans warming and rainfall patterns shifting towards more rain in the summer, the report said.

Each decade has been warmer than the previous decade since the 1950s, it said, with rising greenhouse gas emissions from burning fossil fuels, deforestation and agriculture blamed for the changes.

“We’re certainly seeing where the rain is falling is changing,” Megan Clark, CSIRO’s chief executive, told Reuters. “We’re seeing more in spring and summer … a monsoonal signature across Australia’s north, and more rainfall in central Australia,” she said.

SINGAPORE (Reuters) – The head of the World Bank said on Saturday it is right for the United States to take a leading role in some global institutions and that the right U.S. candidate for post of the bank’s next president would be good for the United States and the bank.

In an interview in Singapore, Robert Zoellick also said he did not believe Spain, Italy or Portugal needed bailouts to ease massive debt burdens but that reforms needed critical support of Germany and other European leading nations.

The World Bank last week launched the nomination process to select a new president to succeed Zoellick when he steps down in June, inviting names from any of its 187 member countries. The Obama administration has said it would open the process to competition.

Some nations say it is time for a non-American candidate to take the helm of the bank, pointing to growing economic clout of the developing world.

Zoellick said he had no role in choosing his successor but made the point that Americans did not hold top posts at the United Nations, World Trade Organization, regional banks or International Monetary Fund.

“I want the United States to feel a sense of responsibility to the international system. So in that sense if you get the right American candidate I think that can be good for the United States and the bank.”

So far, two people most often mentioned as possible successors are both American: U.S. Secretary of State Hillary Clinton and former White House economic adviser and former Treasury Secretary Lawrence Summers. The State Department has insisted that Clinton would not be taking the job.

SINGAPORE, Feb 24 (Reuters) – The World Bank announced on Friday a global alliance to better manage and protect the world’s oceans, which are under threat from over-fishing, pollution and climate change.

Oceans are the lifeblood of the planet and the global economy, World Bank President Robert Zoellick told a conference on ocean conservation in Singapore. Yet the seas have become overexploited, coastlines badly degraded and reefs under threat from pollution and rising temperatures.

“We need a new SOS: Save Our Seas,” Zoellick said in announcing the alliance.

The partnership would bring together countries, scientific centres, non-governmental groups, international organisations, foundations and the private sector, he said.

The World Bank could help guide the effort by bringing together existing global ocean conservation programmes and support efforts to mobilise finance and develop market-mechanisms to place a value on the benefits that oceans provide.

Millions of people rely on oceans for jobs and food and that dependence will grow as the world’s population heads for 9 billion people, underscoring the need to better manage the seas.

Zoellick said the alliance was initially committed to mobilising at least $300 million in finance.