Climate inaction catastrophic - US - By BBC

The costs of inaction on climate change will be "catastrophic", according to US Secretary of State John Kerry.

Mr Kerry was responding to a major report by the UN which described the impacts of global warming as "severe, pervasive and irreversible".

He said dramatic and swift action was required to tackle the threats posed by a rapidly changing climate.

Our health, homes, food and safety are all likely to be threatened by rising temperatures, the report says.

Scientists and officials meeting in Japan say the document is the most comprehensive assessment to date of the impacts of climate change on the world.

In a statement, Mr Kerry said: "Unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy. Denial of the science is malpractice.

"There are those who say we can't afford to act. But waiting is truly unaffordable. The costs of inaction are catastrophic."

Rajendra Pachauri, chair of the Intergovernmental Panel on Climate Change (IPCC), which produced the report, told BBC News: "Even in rich countries, the impacts of climate change could lead to greater incidents of pockets of poverty, even in rich countries could lead to impoverishment of some particular communities.

"However there is an equity issue, because some of the poorest communities in the poorest countries in the world are going to be the worst hit."

Some impacts of climate change include a higher risk of flooding and changes to crop yields and water availability. Humans may be able to adapt to some of these changes, but only within limits.

An example of an adaptation strategy would be the construction of sea walls and levees to protect against flooding. Another might be introducing more efficient irrigation for farmers in areas where water is scarce.

Natural systems are currently bearing the brunt of climatic changes, but a growing impact on humans is feared.

Members of the IPCC say it provides overwhelming evidence of the scale of these effects.

The report was agreed after almost a week of intense discussions here in Yokohama, which included concerns among some authors aboutthe tone of the evolving document.

This is the second of a series from the UN's climate panel due out this year that outlines the causes, effects and solutions to global warming.

This latest Summary for Policymakers document highlights the fact that the amount of scientific evidence on the impacts of warming has almost doubled since the last report in 2007.

Be it the melting of glaciers or warming of permafrost, the summary highlights the fact that on all continents and across the oceans, changes in the climate have caused impacts on natural and human systems in recent decades.

In the words of the report, "increasing magnitudes of warming increase the likelihood of severe, pervasive and irreversible impacts".

"Nobody on this planet is going to be untouched by the impacts of climate change,'' said Mr Pachauri.

Dr Saleemul Huq, a convening lead author on one of the chapters, commented: "Before this we thought we knew this was happening, but now we have overwhelming evidence that it is happening and it is real."

Michel Jarraud, secretary-general of the World Meteorological Organization, said the report was based on more than 12,000 peer-reviewed scientific studies. He said this document was "the most solid evidence you can get in any scientific discipline".

Ed Davey, the UK Energy and Climate Secretary said: "The science has clearly spoken. Left unchecked, climate change will impact on many aspects of our society, with far reaching consequences to human health, global food security and economic development.

"The recent flooding in the UK is a testament to the devastation that climate change could bring to our daily lives."

The report details significant short-term impacts on natural systems in the next 20 to 30 years. It details five reasons for concern that would likely increase as a result of the warming the world is already committed to.

These include threats to unique systems such as Arctic sea ice and coral reefs, where risks are said to increase to "very high" with a 2C rise in temperatures.

The summary document outlines impacts on the seas and on freshwater systems as well. The oceans will become more acidic, threatening coral and the many species that they harbour.

On land, animals, plants and other species will begin to move towards higher ground or towards the poles as the mercury rises.

Humans, though, are also increasingly affected as the century goes on.

Food security is highlighted as an area of significant concern. Crop yields for maize, rice and wheat are all hit in the period up to 2050, with around a tenth of projections showing losses over 25%.

After 2050, the risk of more severe yield impacts increases, as boom-and-bust cycles affect many regions. All the while, the demand for food from a population estimated to be around nine billion will rise.

Many fish species, a critical food source for many, will also move because of warmer waters.

In some parts of the tropics and in Antarctica, potential catches could decline by more than 50%.

"This is a sobering assessment," said Prof Neil Adger from the University of Exeter, another IPCC author.

"Going into the future, the risks only increase, and these are about people, the impacts on crops, on the availability of water and particularly, the extreme events on people's lives and livelihoods."

People will be affected by flooding and heat related mortality. The report warns of new risks including the threat to those who work outside, such as farmers and construction workers. There are concerns raised over migration linked to climate change, as well as conflict and national security.

Report co-author Maggie Opondo of the University of Nairobi said that in places such as Africa, climate change and extreme events mean "people are going to become more vulnerable to sinking deeper into poverty".

While the poorer countries are likely to suffer more in the short term, the rich won't escape.

"The rich are going to have to think about climate change. We're seeing that in the UK, with the floods we had a few months ago, and the storms we had in the US and the drought in California," said Dr Huq.

IPCC Chairman Rajendra Pachauri said the findings in the report were "profound"

"These are multibillion dollar events that the rich are going to have to pay for, and there's a limit to what they can pay."

But it is not all bad news, as the co-chair of the working group that drew up the report points out.

"I think the really big breakthrough in this report is the new idea of thinking about managing climate change as a problem in managing risks," said Dr Chris Field.

"Climate change is really important but we have a lot of the tools for dealing effectively with it - we just need to be smart about it."

There is far greater emphasis to adapting to the impacts of climate in this new summary. The problem, as ever, is who foots the bill?

"It is not up to IPCC to define that," said Dr Jose Marengo, a Brazilian government official who attended the talks.

"It provides the scientific basis to say this is the bill, somebody has to pay, and with the scientific grounds it is relatively easier now to go to the climate negotiations in the UNFCCC (United Nations Framework Convention on Climate Change) and start making deals about who will pay for adaptation."

Panel’s Warning on Climate Risk: Worst Is Yet to Come

By JUSTIN GILLISMARCH 31, 2014 NYtimes

YOKOHAMA, Japan — Climate change is already having sweeping effects on every continent and throughout the world’s oceans, scientists reported on Monday, and they warned that the problem was likely to grow substantially worse unless greenhouse emissions are brought under control.

The report by the Intergovernmental Panel on Climate Change, a United Nations group that periodically summarizes climate science, concluded that ice caps are melting, sea ice in the Arctic is collapsing, water supplies are coming under stress, heat waves and heavy rains are intensifying, coral reefs are dying, and fish and many other creatures are migrating toward the poles or in some cases going extinct.

The oceans are rising at a pace that threatens coastal communities and are becoming more acidic as they absorb some of the carbon dioxide given off by cars and power plants, which is killing some creatures or stunting their growth, the report found.

Organic matter frozen in Arctic soils since before civilization began is now melting, allowing it to decay into greenhouse gases that will cause further warming, the scientists said. And the worst is yet to come, the scientists said in the second of three reports that are expected to carry considerable weight next year as nations try to agree on a new global climate treaty.

In particular, the report emphasized that the world’s food supply is at considerable risk — a threat that could have serious consequences for the poorest nations.

“Nobody on this planet is going to be untouched by the impacts of climate change,” Rajendra K. Pachauri, chairman of the intergovernmental panel, said at a news conference here on Monday presenting the report.

The report was among the most sobering yet issued by the scientific panel. The group, along with Al Gore, was awarded the Nobel Peace Prize in 2007 for its efforts to clarify the risks of climate change. The report is the final work of several hundred authors; details from the drafts of this and of the last report in the series, which will be released in Berlin in April, leaked in the last few months.

The report attempts to project how the effects will alter human society in coming decades. While the impact of global warming may actually be moderated by factors like economic or technological change, the report found, the disruptions are nonetheless likely to be profound. That will be especially so if emissions are allowed to continue at a runaway pace, the report said.

It cited the risk of death or injury on a wide scale, probable damage to public health, displacement of people and potential mass migrations.

“Throughout the 21st century, climate-change impacts are projected to slow down economic growth, make poverty reduction more difficult, further erode food security, and prolong existing and create new poverty traps, the latter particularly in urban areas and emerging hot spots of hunger,” the report declared.

The report also cited the possibility of violent conflict over land, water or other resources, to which climate change might contribute indirectly “by exacerbating well-established drivers of these conflicts such as poverty and economic shocks.”

The scientists emphasized that climate change is not just a problem of the distant future, but is happening now.

Studies have found that parts of the Mediterranean region are drying out because of climate change, and some experts believe that droughts there have contributed to political destabilization in the Middle East and North Africa.

In much of the American West, mountain snowpack is declining, threatening water supplies for the region, the scientists said in the report. And the snow that does fall is melting earlier in the year, which means there is less melt water to ease the parched summers. In Alaska, the collapse of sea ice is allowing huge waves to strike the coast, causing erosion so rapid that it is already forcing entire communities to relocate.

“Now we are at the point where there is so much information, so much evidence, that we can no longer plead ignorance,” Michel Jarraud, secretary general of the World Meteorological Organization, said at the news conference.

The report was quickly welcomed in Washington, where President Obama is trying to use his executive power under the Clean Air Act and other laws to impose significant new limits on the country’s greenhouse emissions. He faces determined opposition in Congress.

“There are those who say we can’t afford to act,” Secretary of State John Kerry said in a statement. “But waiting is truly unaffordable. The costs of inaction are catastrophic.”

Amid all the risks the experts cited, they did find a bright spot. Since the intergovernmental panel issued its last big report in 2007, it has found growing evidence that governments and businesses around the world are making extensive plans to adapt to climate disruptions, even as some conservatives in the United States and a small number of scientists continue to deny that a problem exists.

“I think that dealing effectively with climate change is just going to be something that great nations do,” said Christopher B. Field, co-chairman of the working group that wrote the report and an earth scientist at the Carnegie Institution for Science in Stanford, Calif. Talk of adaptation to global warming was once avoided in some quarters, on the ground that it would distract from the need to cut emissions. But the past few years have seen a shift in thinking, including research from scientists and economists who argue that both strategies must be pursued at once.

A striking example of the change occurred recently in the state of New York, where the Public Service Commission ordered Consolidated Edison, the electric utility serving New York City and some suburbs, to spend about $1 billion upgrading its system to prevent future damage from flooding and other weather disruptions.

The plan is a reaction to the blackouts caused by Hurricane Sandy. Con Ed will raise flood walls, bury some vital equipment and conduct a study of whether emerging climate risks require even more changes. Other utilities in the state face similar requirements, and utility regulators across the United States are discussing whether to follow New York’s lead.

But with a global failure to limit greenhouse gases, the risk is rising that climatic changes in coming decades could overwhelm such efforts to adapt, the panel found. It cited a particular risk that in a hotter climate, farmers will not be able to keep up with the fast-rising demand for food.

“When supply falls below demand, somebody doesn’t have enough food,” said Michael Oppenheimer, a Princeton University climate scientist who helped write the new report. “When some people don’t have food, you get starvation. Yes, I’m worried.”

The poorest people in the world, who have had virtually nothing to do with causing global warming, will be high on the list of victims as climatic disruptions intensify, the report said. It cited a World Bank estimate that poor countries need as much as $100 billion a year to try to offset the effects of climate change; they are now getting, at best, a few billion dollars a year in such aid from rich countries.

The $100 billion figure, though included in the 2,500-page main report, was removed from a 48-page executive summary to be read by the world’s top political leaders. It was among the most significant changes made as the summary underwent final review during an editing session of several days in Yokohama.

The edit came after several rich countries, including the United States, raised questions about the language, according to several people who were in the room at the time but did not wish to be identified because the negotiations were private. The language is contentious because poor countries are expected to renew their demand for aid this September in New York at a summit meeting of world leaders, who will attempt to make headway on a new treaty to limit greenhouse gases.

Many rich countries argue that $100 billion a year is an unrealistic demand; it would essentially require them to double their budgets for foreign aid, at a time of economic distress at home. That argument has fed a rising sense of outrage among the leaders of poor countries, who feel their people are paying the price for decades of profligate Western consumption.

Two decades of international efforts to limit emissions have yielded little result, and it is not clear whether the negotiations in New York this fall will be any different. While greenhouse gas emissions have begun to decline slightly in many wealthy countries, including the United States, those gains are being swamped by emissions from rising economic powers like China and India.

For the world’s poorer countries, food is not the only issue, but it may be the most acute. Several times in recent years, climatic disruptions in major growing regions have helped to throw supply and demand out of balance, contributing to price increases that have reversed decades of gains against global hunger, at least temporarily.

The warning about the food supply in the new report is much sharper in tone than any previously issued by the panel. That reflects a growing body of research about how sensitive many crops are to heat waves and water stress. The report said that climate change was already dragging down the output of wheat and corn at a global scale, compared with what it would otherwise be.

David B. Lobell, a Stanford University scientist who has published much of the recent research and helped write the new report, said in an interview that as yet, too little work was being done to understand the risk, much less counter it with improved crop varieties and farming techniques. “It is a surprisingly small amount of effort for the stakes,” he said.

Timothy Gore, an analyst for Oxfam, the antipoverty group that sent observers to the proceedings in Yokohama, praised the new report as painting a clear picture of the consequences of a warming planet. But he warned that without greater efforts to limit global warming and to adapt to the changes that have become inevitable, “the goal we have in Oxfam of ensuring that every person has enough food to eat could be lost forever.”

Water dispute between São Paulo State and Rio de Janeiro State ( Brazil ) GreenHouse Effect

http://www1.folha.uol.com.br/cotidiano/2014/03/1429820-alckmin-rebate-cabral-e-diz-que-rio-e-dos-paulistas.shtml

House hunting in a hurricane zone

27 February 2014
By Karina Martinez-Carter

It’s been a tough couple of years for homeowners. Extreme weather events over the last 18 months have wreaked havoc on residential property around the world. Bushfires have raged across Australia, huge storms have slammed the United States and UK homes have been flooded.

New Jersey resident Elaine Burns saw her Little Silver home flooded with eight feet of water when October’s superstorm Sandy hit the US east coast. Still, she believes she was lucky. The storm “clobbered” many of their immediate neighbours’ homes, she said. Hers, at least, was still intact.

 “With all of this discussion about the sea level rising long-term, you have to wonder whether this a once-in-a-lifetime event, or something that happens once every so many years,” she said. “That’s the challenge here.”

Burns and her husband, like many others, have had to pour cash into protecting their house in case floodwaters surge again, such as hanging or elevating kitchen appliances. Her neighbours are lifting their home about eight feet off the ground with a new foundation — a lengthy, intense and extensive process that’s necessary both for future safety and more. Such precautions are becoming almost required if an owner in a storm-struck area ever wants to sell.

Yet there is a silver lining to catastrophe. People on all sides of the property fence, including the insurance industry and property agents, say they have become more nimble, experienced and efficient at responding to weather-related disasters. Homeowners, too, can benefit from the many lessons learned by those who have been struck by calamity.

Here’s a look at how real estate professionals, governments, buyers and sellers and insurers have adjusted, and what homeowners should do to protect their properties.

Real estate agents

Real estate agents now say they better understand how to protect vulnerable zones, and they are passing their knowledge on to buyers and homeowners.

For instance, following bushfires in Australia, Sue Swingler, a property agent in the arid state of Victoria, now advises clients to access local authority risk maps of their properties. No matter where homeowners live, reputable insurance companies should provide estimates for the area, as well as regional comparisons.

In many disaster-prone areas, agents are now required by law to say whether the area or property faces risky weather. Stay up-to-date on rules and regulations, which often change following a disaster, Swingler suggested. Consult property or insurance agents, or search online government resources.

Beware bargain hunters who seek to scoop up property after a calamity, agents say. “We worked hard to keep the land prices generally in keeping to the prices pre-fires,” said Swingler. Real estate agents discourage sellers from taking less than their property is worth.

Agents have also begun to take on more of an advisory role. That can be very good news for homeowners, who should seek to find these proactive advisors. “We will talk about the need for a fire plan and refer [prospective buyers] to the respective [local] authority for more information,” Swingler said.

Hands-on agents may urge buyers to consider whether there might be a more resilient property available in their price range and target area. Flood maps might show a home on one street as sitting in a higher danger zone than one for sale a street away.

Agents in fire-prone areas will tell sellers to look at the vegetation and water supply around a property, added Mark Sutherland, another property agent in Victoria. Agents have even begun helping residents in the wake of a crisis, including clearing away brushes and trees, aiding in obtaining new building permits or even relocating displaced owners.

Insurers

Insurance and reinsurance industries have also learned from natural disasters, said Dr Sebastian von Dahlen, economic counsellor for the International Association of Insurance Supervisors (IAIS) in Basel, Switzerland.

For one, insurance companies are taking preventative measures at the sign of an impending storm or disaster. US-based auto insurance company Allstate, for instance, boosted its presence in threatened areas and deployed a number of mobile claim centres and response vehicles even before superstorm Sandy made landfall.

For property owners, insurance and reinsurance for disaster-apt property is still not prohibitively expensive, said Von Dahlen. Still, they should be aware of possible price fluctuations.

Purchasing appropriate insurance — while it sounds obvious — is more crucial than ever because disasters that aren’t covered by basic home insurance are becoming more frequent. The good news is that with the right insurance, you may be paid out for a claim quicker than in the past. The UK’S biggest insurance body, The Association of British Insurers claims the industry has distributed about £14 million($23.5m) in emergency payments since 23 December when severe flooding began in the south of the country.

Governments

Governments around the world are learning from others’ calamities and are better (in some cases) about stepping in with aid earlier.

After Sandy, the New Jersey government offered buyout plans to property owners across a number of affected areas, largely financed by federal disaster funds. It purchased large sections of land to create a natural buffer to protect against future disasters. The Canadian government enacted a similar plan in Alberta.

In many places, law now requires property agents to be transparent about disaster risks. For example, in the UK, property agents have “a legal obligation to inform buyers of anything that would affect their transactional decision,” said Mark Hayward, the UK’s National Association of Estate Agents managing director. In Australia, vendors must declare in the vendor statement if the property up for sale is located in a bushfire zone.

Buyers and Sellers—The Silver Lining

 As owners, buyers and sellers have seen nearby properties slammed by natural disasters, they have become savvier about how to protect their own.

For homes that might face flooding, even slight changes can help, such as raising electrical sockets, landscaping to create barriers to block water and replacing flooring with a water-resistant material. Such adjustments safeguard the property in the present and often lead to more affordable insurance premiums. Once a property is for sale, the measures also make it more appealing to buyers — and can set one house on the block apart from another.

Similarly, buyers are becoming more aware about what to look for in a property, from where appliances are situated, to what type of insurance is required and how close the property lies to a flood plain.

While Burns and her family have stayed in their home on a peninsula that juts into the Shrewsbury River, some of her neighbours have opted to sell. And the truth is, come hell or high water, many buyers will continue to covet those waterfront properties

Nível de reservas da Cantareira é o menor desde o início de suas operações - Brazil

FERNANDA GUIMARÃES - Agência Estado

O índice que mede o volume de água armazenado no Sistema Cantareira apresentou nova queda neste sábado, caindo para 17,5% da capacidade total dos reservatórios ante o nível de 17,7% registrado na sexta. Este é o índice mais baixo apresentado desde o início de operação do sistema, em 1974. 

De acordo com dados da Sabesp, a pluviometria ds região acumulada em fevereiro permanece em 48,7 milímetros (mm), o que representa somente 24% da média histórica de chuvas para o mês. A pluviometria de hoje, ainda de acordo com a Sabesp, foi de 0,1 mm, apesar de ter chovido forte em algumas regiões de São Paulo na tarde de hoje.

Conforme os meteorologistas do Centro de Gerenciamento de Emergências (CGE), as próximas horas ainda devem seguir com registro de chuvas na Capital, entretanto de maneira fraca e com eventuais pontos moderados. Para amanhã são aguardadas pancadas de chuvas a partir do meio da tarde. Na segunda-feira a partir da tarde estão previstas pancadas de chuva com intensidade de moderada a forte.

Freezing January for Easterners Was Not Felt Round the World

An abandoned farmhouse near Bakersfield, Calif., in February. California is struggling with a severe drought. David McNew/Getty Images

By JUSTIN GILLISFEB. 20, 2014

For people throughout the Eastern United States who spent January slipping, sliding 

and shivering, here is a counterintuitive fact: For the earth as a whole, it was the

fourth-warmest January on record.

It was, in fact, the 347th consecutive month with temperatures above the 20th-century average, the government reported Thursday.

That may feel plausible to Californians, whose state experienced temperatures 10 or 15 degrees above normal in some places last month, and especially to Alaskans, where the average temperature was almost 15 degrees above normal.

But on a map of January temperatures released Thursday by government weather analysts, the Eastern United States stood out as one of the coldest areas on the planet, compared with seasonal norms.

That is no surprise to anybody living east of the Mississippi River, of course — certainly not to the Atlantans who were caught up in two memorable ice storms that shut down the city, or the New Yorkers who are still picking their way through mounds of dirty snow.

But this might be another surprise: Despite all the weather drama, it was not a January for the record books.

By the time analysts averaged the heat in the West and the cold in the East, the national temperature for the month fell only one-tenth of a degree below the 20th-century average for January. January 2011 was colder.

No state set a monthly record for January cold. Alabama, also walloped by the ice storms, came closest, with the fourth-coldest January on its record books.

The United States covers only 2 percent of the surface of the globe, so what happens in this country does not have much influence on overall global temperatures.

Brazil, much of southern Africa, most of Europe, large parts of China and most of Australia were unseasonably warm in January, the National Oceanic and Atmospheric Administration reported Thursday. That continues a pattern of unusual global warming that is believed to be a consequence of human-caused emissions of greenhouse gases.

Even in the United States, more than a third of the country is in drought of varying intensity. Mountain snowpack in many parts of the West is only half of normal, portending a parched summer and a likelihood of severe wildfires.

“Today’s snowpack is tomorrow’s water in the West,” said Deke Arndt, chief of climate monitoring for the National Climatic Data Center in Asheville, N.C., in a briefing on Thursday. “If it does not recover, this will have consequences for months down the road.”

The Arctic blasts of this winter do stand out in the weather records of this young century, even if they are pretty humdrum when compared with the 1970s and 1980s. Winters have been so mild over the past couple of decades — probably as a result of global warming, scientists say — that some young adults have never experienced cold waves quite so intense.

And the pain may not be over. Forecasters say the northern tier of the United States

may face still more cold blasts, storms and heavy winds right up to the doorstep of 

spring, albeit interspersed with bursts of warmth in some areas.

Over just the next few days, the Southeast may be hit by severe thunderstorms, high winds and even hail. The Midwest may have wind gusts up to 60 miles an hour. And the Northeast could see rain, snow or a mix of the two.

Temperatures across the eastern Great Plains, the Great Lakes and the Mississippi Valley are expected to be below normal for the next month and into the spring.

But the cold weather in the East is being balanced, in a sense, by the bizarrely warm temperatures in the West. And that trend, too, is likely to continue.

The outlook over the next month is for continued above-normal temperatures in the West, the Southwest and parts of Alaska, as well as a continuation of the California drought, despite recent rains that have eased the situation slightly.

The extremes in January were directly related, experts said, with the two regions falling on opposite sides of a big loop in the jet stream, a belt of high winds in the upper atmosphere that helps to regulate the climate.

A dip of the jet stream into the Eastern United States allowed cold air to descend from the Arctic, while a corresponding ridge in the West allowed warm air to hover over California and to penetrate normally frigid regions to the north.

For those ready for the warmth to dip in their direction, mark a calendar: March 20, at 12:57 p.m. Eastern Daylight Time.

That is when the tilt of the Earth causes the sun to pass over the Equator and re-enter the Northern Hemisphere, bringing spring with it.

Science Linking Drought to Global Warming Remains Matter of Dispute - longstanding prediction that wet areas of the world will get wetter in a warming climate, even as the dry ones get drier.

By JUSTIN GILLISFEB. 16, 2014   NYtimes.com

In delivering aid to drought-stricken California last week, President Obama and his aides cited the state as an example of what could be in store for much of the rest of the country as human-caused climate change intensifies.

But in doing so, they were pushing at the boundaries of scientific knowledge about the relationship between climate change and drought. While a trend of increasing drought that may be linked to global warming has been documented in some regions, including parts of the Mediterranean and in the Southwestern United States, there is no scientific consensus yet that it is a worldwide phenomenon. Nor is there definitive evidence that it is causing California’s problems.

In fact, the most recent computer projections suggest that as the world warms, California should get wetter, not drier, in the winter, when the state gets the bulk of its precipitation. That has prompted some of the leading experts to suggest that climate change most likely had little role in causing the drought.

“I’m pretty sure the severity of this thing is due to natural variability,” said Richard Seager, a climate scientist who studies water issues at the Lamont-Doherty Earth Observatory of Columbia University.

To be sure, 2013 was the driest year in 119 years of record keeping in California. But extreme droughts have happened in the state before, and the experts say this one bears a notable resemblance to some of those, including a crippling drought in 1976 and 1977.

Over all, drought seems to be decreasing in the central United States and certain other parts of the world, though that is entirely consistent with the longstanding prediction that wet areas of the world will get wetter in a warming climate, even as the dry ones get drier.

What may be different about this drought is that, whatever the cause, the effects appear to have been made worse by climatic warming. And in making that case last week, scientists said, the administration was on solid ground.

California has been warming along with most regions of the United States, and temperatures in recent months have been markedly higher than during the 1976-77 drought. In fact, for some of the state’s most important agricultural regions, summer lasted practically into January, with high temperatures of 10 or 15 degrees above normal on some days.

The consequence, scientists say, has been that any moisture the state does get evaporates more rapidly, intensifying the effects of the drought on agriculture in particular. “We are going through a pattern we’ve seen before, but we’re doing it in a warmer environment,” said Michael Anderson, the California state climatologist.

The White House science adviser, John P. Holdren, said in a briefing last week: “Scientifically, no single episode of extreme weather, no storm, no flood, no drought can be said to have been caused by global climate change. But the global climate has now been so extensively impacted by the human-caused buildup of greenhouse gases that weather practically everywhere is being influenced by climate change.”

The drought eased a bit with heavy rains in Northern California this month, but many major reservoirs have only half the water expected for this time of year. “I think the situation is still pretty severe,” said Prof. Alex Hall, who studies climate at the University of California, Los Angeles.

California gets much of its water from snow in the winter along the western slopes of the Sierra Nevada. That means 38 million people and a $45 billion agricultural economy are critically dependent on about five heavy storms a year.

Dry Western States

Rain and snow in California have been so minimal over the last three years that 95 percent of the state is in drought. Neighboring states like Nevada have also been hard-hit.

If a ridge of high atmospheric pressure develops off the California coast, it can easily push moisture-bearing winds to the north, so that the water falls closer to Seattle than Sacramento. Just such a ridge has been parked off California for much of the last three years.

A decade ago, scientists at the University of California, Santa Cruz, published a tantalizing set of papers that predicted a greater likelihood of such a ridge. The lead researcher, Jacob O. Sewall, harnessed substantial computing power to run forecasts of what would happen in a future climate after a substantial melting of sea ice in the Arctic. The ice is already melting because of fast-rising temperatures in the region that many scientists attribute to human emissions.

Dr. Sewall expected some sort of disturbance in the circulation of the atmosphere, but he and his adviser, Lisa Cirbus Sloan, were not prepared for the answer they received. “The surprise jumped out that, wow, all of a sudden it got a whole lot drier in the western part of North America,” Dr. Sewall recalled.

His first study on the question was published in 2004, and was based on conditions that were expected by midcentury. Arctic sea ice then fell much faster than expected, hitting a record low in 2007 and then another record low in 2012.

He and several other scientists said the loss of ice has allowed extra heat to escape from the Arctic Ocean into the atmosphere in the fall and early winter, disturbing weather patterns over vast distances. That, they said, has made extreme weather events of all kinds more likely in the Northern Hemisphere, possibly including winter extremes like the cold blasts hitting the East Coast these days.

At the same time, the California drought, now in its third year, bears a striking resemblance to the atmospheric pattern predicted in Dr. Sewall’s computer analysis.

The resemblance is so uncanny that Dr. Sewall, who now works at Kutztown University in Pennsylvania, suspects an element of coincidence, but he also calls the correlation “frightening.” If this kind of drought has indeed become more likely for California, that means the state — where some towns are now worried about running out of drinking water — is getting a glimpse of its future.

Since his studies were published, other research has come to somewhat different conclusions. Many of those studies have found a likelihood that climate change will indeed cause the American West to dry out, but by an entirely different mechanism — the arrival of more dry air from the tropics. And the most recent batch of studies predicts that effect will not really apply to the western slope of the Sierra. Climate projections show that the area should get somewhat more moisture in the winter, not less.

It may take years to resolve the scientific uncertainty. But with California’s growing population, the state faces increasing pressure to resolve tensions involved in apportioning its water among city dwellers, farmers, industry and an environment under increasing strain from global warming.

Dr. Seager of Columbia University pointed out that much of the Southwestern United States had been in a drought of fluctuating severity for 15 years. In some areas, moreover, the warmer climate is causing winter precipitation to fall as rain rather than snow, meaning less melting snowpack to help parched states through the hotter summers.

“It all adds up across the Southwest to an increasingly stressed water system,” he said. “That’s what they might as well get ready for.”