Fakta@MKST: Global Warming [2011 tahun ke-9 terpanas sejak 1880]

dauswq

Please paste  the latest info regarding global warming here

any valuable information and critical postings will get rewarded

ScienceNews




While most folks are breaking out their shorts and swimsuits for a summer of play, some researchers are packing warm-weather gear for a much colder trip — to Arctic ice.

June is the time when polar scientists start to scrutinize in earnest how much ice will be left atop the Arctic Ocean after this year’s summer melt season. The National Snow and Ice Data Center in Boulder, Colo., reported this week that ice extent — a measure of total ice-covered area, including some gaps in the ice
— was, at the end of May, close to the lowest ever recorded for that time of year.

Ice extent reaches its nadir each September, at the end of the melt season, and something of a cottage industry has sprung up in recent years to predict the final number. But melting ice is a complicated thing, as discussed in a recent Science News feature story, and many such predictions often end up spectacularly off-base. Last year, for instance, every single team of scientists that hazarded an official guess was quite a bit off.

That’s because weather patterns in the Arctic play a major role in determining how much sea ice vanishes in any given year. A couple of strong winds here, an anomalous cold patch there, and suddenly a season that looked like a disastrous meltdown turns out to be almost average. So the dramatic-looking lows at the end of May are no guarantee that overall ice levels will be a record-breaker this year.

Still, there’s no denying the remarkable overall decline of Arctic ice cover since satellite observations began in 1979. Accordingly, among the many expeditions heading north this summer will be a NASA-sponsored cruise called ICESCAPE, for Impacts of Climate Change on the Ecosystems and Chemistry of the Arctic Pacific Environment. The research will focus primarily on biogeochemistry and ecology in the Beaufort and Chukchi seas north of Alaska.

Scientists will depart on the U.S. Coast Guard icebreakerHealy from the Aleutian islands June 15 for a five-week voyage. Don Perovich, a sea-ice expert on the cruise, told reporters this week that the Healy would send back sea-ice conditions every two hours as it transits north. “Our observations will be directly tied in to people trying to estimate what conditions will be like in September, whether we have a record minimum or not,” he says.

At this point, the best anyone can say about what to expect from the Arctic in 2010 is: Check back in the fall.

Credit: ScienceNews

dauswq

Study examines scientists' 'climate credibility'
By Pallab Ghosh
            

  
Most experts agreed human activity was affecting the climate system


                     

Some 98% of climate scientists that publish research on the subject support the view that human activities are warming the planet, a study suggests.

        
It added there was little disagreement among the most experienced scientists.

        
But climate sceptics questioned the findings, saying that publication in scientific journals was not a fair test of expertise.        
The findings have been published in the journal Proceedings of the National Academy of Sciences.

        
The study's authors said they found "immense" differences in both the expertise and scientific prominence of those who supported the "primary tenets" of latest assessments made by the Intergovernmental Panel on Climate Change (IPCC) and those who were sceptical of the IPCC's findings.

        

In general, they added, the researchers who were convinced of the human impact on climate change had published twice as many papers as their sceptical counterparts, and were cited in other people's research two to three times more often.

It's typical of this broad-brush study to make such wide ranging claims similar to the infamous 'the debate is over'

        Professor Hans von Storch        University of Hamburg Lead author William Anderegg, from Stanford University in California, US, said the findings suggested that not all experts were equal in what they claimed.


        
"The researchers who are convinced (by the IPCC's assessment reports) have a lot more experience in climate research and have published a lot more papers in the scientific literature and are generally well respected in their field," he said.         
"And it also demonstrates the converse that those who are sceptical of the IPCC's claims, in general, know a lot less about the climate system."

        
Mr Anderegg and his colleagues drew from a list of 908 researchers who had contributed to research used by the IPCC and have signed statements broadly in support of the UN body's assessments.

        
On the sceptical side, they chose 475 scientists from a list of 11 major sceptical declarations and open letters.        
The researchers said they felt the need to carry out the survey because of the growing public perception that scientific opinion was divided on the issue following recent scandals, such as "climategate" at the UK's University of East Anglia and  the use of non-peer reviewed literature in the IPCC findings.

        
"We really felt that the state of the scientific debate was so far removed from the state of the public discourse and we felt that a good quantitative, rigorous comparison of this would put to rest the notion that the scientists 'disagree' about global warming," Mr Anderegg told BBC News.


  'Broad-brush study'      
Sceptical groups, however, argued that publication in scientific journals was not a fair test of expertise.         
They said that those who choose which papers to publish favoured research that supported the IPCC's view, and suggested that the new study was tautologous.

        
Professor Hans von Storch, from the Meteorological Institute of the University of Hamburg, said: "You have to ask yourself - which are the the tenets of (the human induced climate change) outlined by the IPCC the '"convinced" groups of scientists agree with.         
"There is a core of assertions, dealing with the effect of greenhouse gases on temperature and sea level, which enjoy general agreement," Professor von Storch told BBC News.

        
"While others, for instance, related to the Himalaya glaciers, the changing tropical storms and their damages or the fate of Greenland, are heavy contested.

        
"It's typical of this broad-brush study to make such wide ranging claims similar to the infamous 'the debate is over'."        
Dr Sonja Boehmer-Christiansen, from the University of Hull, UK, added: "Who judges expertise and prominence? It looks to me that the authors belong to an IPCC  supporting group that must count as believers and belong to the beneficiaries of the man-made warming scare."

Sumber: http://news.bbc.co.uk/2/hi/science_and_environment/10370955.stm

kucingblue

you know, i think some people are confused about the debate in global warming. I think some people can't tell the difference whether "global warming is real" or "if it's caused by human activities".

It's not such a big deal for me if people don't believe that human activities caused it. yeah, it's true, consensus among leading scientists is that it is caused by humans. Logically speaking, it would only make it a STRONG argument to claim that it is caused by human activities because experts in the field generally think so.

But I have a problem when people don't even believe that global warming is happening. If you wanna know that something is warming up, what do you do? You measure the temperature. And global surface temperature trend is going up. What does it mean? It ABSOLUTELY means that the earth is warming up, be it due to human activity, or natural phenomena. It is warming up. I can't think of a reason why anybody would deny that, other than, well, stupidity.

dauswq

Methane releases in arctic seas could wreak devastation




Massive releases of methane from arctic seafloors could create oxygen-poor dead zones, acidify the seas and disrupt ecosystems in broad parts of the northern oceans, new preliminary analyses suggest.

Such a cascade of geochemical and ecological ills could result if global warming triggers a widespread release of methane from deep below the Arctic seas, scientists propose in the June 28 Geophysical Research Letters.


Worldwide, particularly in deeply buried permafrost and in high-latitude ocean sediments where pressures are high and temperatures are below freezing, icy deposits called hydrates hold immense amounts of methane (SN: 6/25/05, p. 410). Studies indicate that seafloor sediments beneath the Kara, Barents and East Siberian seas in the Arctic Ocean, as well as the Sea of Okhotsk and the Barents Sea in the North Pacific, have large reservoirs of the planet-warming greenhouse gas, says study coauthor Scott M. Elliott, a marine biogeochemist at Los Alamos National Laboratory in New Mexico.


Many oceanographic surveys have already discovered plumes of methane rising from the ocean floor, particularly in the Arctic, Elliott notes. The climate warming expected in coming decades will likely extend even into the deep sea, melting or destabilizing hydrates and releasing their trapped methane, he explains. Some scientists estimate that increased temperatures across some swaths of ocean floor between 300 and 600 meters deep — where methane hydrates are now stable but may not be in the future — could eventually release as much as 16,000 metric tons of methane each year.

That methane would be an unexpected bounty for methane-munching marine microbes that consume dissolved oxygen and produce carbon dioxide. As a result, the researchers’ model suggests, the waters down-current of a large methane plume, especially in an ocean basin with poor circulation, could lose as much as 95 percent of their oxygen.

The ocean acidification that resulted from the increased carbon dioxide would rival that seen in surface waters under today’s atmosphere, which is already stifling the growth of phytoplankton, rendering the shells of marine snails thinner (SN: 10/20/07, p. 245) and affecting marine ecosystems worldwide (SN: 7/17/04, p. 35).

“This will be a truly big environmental pollution problem in the next few decades,” Elliott contends. “This problem is not going to go away.”


Besides generating large volumes of acidified water and low-oxygen dead zones, the microbial activity will rob the waters of key nutrients — including nitrate, copper and iron — that otherwise would be used by microorganisms that don’t feed on methane. Many of these nutrients are already sparse, and the resulting shift in populations among the fiercely competitive microorganisms at the base of the ocean’s food chain in many regions could be devastating, the researchers suggest.

“This is an interesting possibility,” says David Valentine, a microbial geochemist at University of California, Santa Barbara. The team has taken what we know about methane-consuming organisms and placed it in the context of a warming Arctic,” he notes.

Nevertheless, he continues, the largest rates of methane release considered by the researchers “are considerably larger than scientists have seen in the Arctic recently.


“They picked a very large [methane] flux, in my estimation”, he says. “But there’s very little doubt that if methane emissions are as large as this, there will be severe biological and geochemical impacts.”

Future work will refine the new study’s preliminary results, says Elliott. In areas where river deltas inject organic material and dissolved trace elements into the sea, for instance, it’s not clear how all of the intricately related processes will affect water chemistry.

On the whole, though, the cascade of ecological effects envisioned by Elliott and his colleagues are a reasonable scenario, Valentine says. “The same sort of processes are seen in the dead zones in many lakes and oceans today,” he notes.



*Credit to ScienceNews

dauswq

66 mati kepanasan di Jepun


2010/07/28      TOKYO: Sekurang-kurangnya 66 orang maut manakala 15,000 lagi dirawat di hospital kerana tidak tahan dengan cuaca panas sejak dua bulan lalu di Jepun.

Suhu luar biasa tinggi bermula sejak berakhirnya musim hujan awal bulan ini dengan suhu mencapai 35 darjah Celcius atau lebih tinggi di 90 peratus daripada
    920 kawasan yang dipantau pihak berkuasa.Laporan itu disiarkan oleh Agensi Kaji Cuaca Jepun mengenai kesan kepanasan melampau sehingga Ahad lalu.

Sehingga hujung minggu lalu, 9,436 orang di seluruh negara itu dibawa ke hospital dan 57 daripada mereka disahkan maut kerana tidak tahan cuaca tinggi, kata Agensi Pengurusan Bencana dan Kebakaran.

Sebahagian lagi yang terkorban disebabkan kemalangan berkaitan dengan penggunaan air hingga ada yang lemas.

Agensi Kaji Cuaca meramalkan suhu tahun ini akan mencapai tahap tertinggi dalam tempoh 100 tahun. Kepanasan yang paling teruk juga menyebabkan jualan air minuman dan alat penghawa dingin melonjak.
Kadar bekalan elektrik juga meningkat kerana penggunaan peralatan penghawa dingin di seluruh negara, menurut laporan.

Syarikat Tokyo Electric Power Co yang membekalkan tenaga kepada lebih 28 juta pelanggan di ibu kota serta wilayah sekitar merekodkan kadar penggunaan tertinggi di Tokyo sebanyak 59,990 megawatt pada 23 Julai lalu,
tertinggi tahun ini, kata firma berkenaan.

Kawasan mencatat suhu tertinggi ialah daerah Tajimi di wilayah Gifu dengan 38.1 darjah Celcius diikuti Sakuma di wilayah Shizuoka (37.9 darjah Celcius).

Secara rasminya, suhu tertinggi pada bulan Julai direkodkan di Okazaki, wilayah Aichi dengan 37.7 darjah Celcius dan Kyotanabe di wilayah Kyoto, 37.3 Celcius.

Angka korban tertinggi cuaca panas sebelum ini dicatat pada 2008 ketika kali pertama data mengenainya disimpan apabila 47 terbunuh pada bulan Julai dan Ogos.
Tahun lalu, 16 orang terbunuh kerana kepanasan melampau juga dalam tempoh dua bulan berkenaan.  Agensi

dauswq

What Is Extreme Heat?

        
Conditions of extreme heat are defined  as summertime temperatures that are substantially hotter and/or more humid than  average for location at that time of year. Humid or muggy conditions, which add  to the discomfort of high temperatures, occur when a "dome" of high  atmospheric pressure traps hazy, damp air near the ground. Extremely dry and  hot conditions can provoke dust storms and low visibility. Droughts occur when  a long period passes without substantial rainfall. A heat wave combined with a  drought is a very dangerous situation.      

During Hot Weather       

To protect your health when temperatures are extremely high, remember to keep cool and use common sense. The following tips are important:        

1. Drink Plenty of Fluids
   
During hot weather you will need to increase your fluid intake, regardless of your activity level. Don't wait until you're thirsty to drink. During heavy exercise in a hot environment, drink two to four glasses (16-32 ounces) of cool fluids each hour.        

Warning: If your doctor generally limits the amount of fluid you drink or has you on water pills, ask how much you should drink while the weather is hot.

        
Don't drink liquids that contain  alcohol, or large amounts of sugar—these actually cause you to lose more body fluid. Also avoid very cold drinks, because they can cause stomach cramps.        

2. Replace Salt and Minerals        
Heavy sweating removes salt and minerals from the body. These are necessary for your body and must be replaced. If you must exercise, drink two to four glasses of cool, non-alcoholic fluids each hour. A sports beverage can replace the salt and minerals you lose in sweat. However, if you are on a low-salt diet, talk with your doctor before drinking a sports beverage or taking salt tablets.   

3. Wear Appropriate Clothing and Sunscreen       
Wear as little clothing as possible when you are at home. Choose lightweight, light-colored, loose-fitting clothing. Sunburn affects your body's ability to cool itself and causes a loss of body fluids. It also causes pain and damages the skin. If you must go outdoors, protect yourself from the sun by wearing a wide-brimmed hat (also keeps you cooler) along with sunglasses, and by putting on sunscreen of SPF 15 or higher (the most effective products say "broad spectrum" or "UVA/UVB protection" on their labels) 30 minutes prior to going out. Continue to reapply it according to the package directions.        

4. Schedule Outdoor Activities Carefully        

If you must be outdoors, try to limit your outdoor activity to morning and evening hours. Try to rest often in shady areas so that your body's thermostat will have a chance to recover.        

5. Pace Yourself        
If you are not accustomed to working or exercising in a hot environment, start slowly and pick up the pace gradually. If exertion in the heat makes your heart pound and leaves you gasping for breath, STOP all activity. Get into a cool area or at least into the shade, and rest, especially if you become lightheaded, confused, weak, or faint.        

6. Stay Cool Indoors        
Stay indoors and, if at all possible, stay in an air-conditioned place. If your home does not have air conditioning, go to the shopping mall or public library—even a few hours spent in air conditioning can help your body stay cooler when you go back into the heat. Call your local health department to see if there are any heat-relief shelters in your area. Electric fans may provide comfort, but when the temperature is in the high 90s, fans will not prevent heat-related illness. Taking a cool shower or bath or moving to an air-conditioned place is a much better way to cool off. Use your stove and oven less to maintain a cooler temperature in your home.      

7. Use a Buddy System        
When working in the heat, monitor the condition of your co-workers and have someone do the same for you. Heat-induced illness can cause a person to become confused or lose consciousness. If you are 65 years of age or older, have a friend or relative call to check on you twice a day during a heat wave. If you know someone in this age group, check on them at least twice a day.      

8.Monitor Those at High Risk        
Although anyone at any time can suffer  from heat-related illness, some people are at greater risk than others.   

   

• Infants and young children are sensitive to the effects of high  temperatures and rely on others to regulate their environments and provide  adequate liquids.
• People 65 years of age or older may not compensate for heat stress efficiently and are less likely to sense and respond to change in temperature.
• People who are overweight may be prone to heat sickness because of their tendency to retain more body heat.
• People who overexert during work or exercise may become dehydrated and susceptible to heat sickness.
• People who are physically ill, especially with heart disease or high blood pressure, or who take certain medications, such as for depression, insomnia, or poor circulation, may be affected by extreme heat.

        
Visit adults at risk at least twice a day and closely watch them for signs of heat exhaustion or heat stroke. Infants and young children, of course, need much more frequent watching.        

9. Adjust to the Environment        
Be aware that any sudden change in temperature, such as an early summer heat wave, will be stressful to your body. You will have a greater tolerance for heat if you limit your physical activity until you become accustomed to the heat. If you travel to a hotter climate, allow several days to become acclimated before attempting any vigorous exercise, and work up to it gradually.        

10. Do Not Leave Children in Cars        
Even in cool temperatures, cars can heat up to dangerous temperatures very quickly. Even with the windows cracked open, interior temperatures can rise almost 20 degrees Fahrenheit within the first 10 minutes. Anyone left inside is at risk for serious heat-related illnesses or even death. Children who are left unattended in parked cars are at greatest risk for heat stroke, and possibly death. When traveling with children, remember to do the following:        

• Never leave infants, children or pets in a parked car, even if the windows are cracked open.
• To remind yourself that a child is in the car, keep a stuffed animal in the car seat. When the child is buckled in, place the stuffed animal in the front with the driver.
• When leaving your car, check to be sure everyone is out of the car. Do not overlook any children who have fallen asleep in the car.

        

11. Use Common Sense       
Remember to keep cool and use common sense:        

• Avoid hot foods and heavy meals—they add heat to your body.
• Drink plenty of fluids and replace salts and minerals in your body. Do not take salt tablets unless under medical supervision.
• Dress infants and children in cool, loose clothing and shade their heads and faces with hats or an umbrella.
• Limit sun exposure during mid-day hours and in places of potential severe exposure such as beaches.
• Do not leave infants, children, or pets in a parked car.
• Provide plenty of fresh water for your pets, and leave the water in a shady area.

dauswq

Marine Phytoplankton Declining: Striking Global Changes at the Base of the Marine Food Web Linked to Rising Ocean Temperatures

ScienceDaily (July 28, 2010)
— A new article published in the 29 July issue of the journal Nature reveals for the first time that microscopic marine algae known as "phytoplankton" have been declining globally over the 20th century. Phytoplankton forms the basis of the marine food chain and sustains diverse assemblages of species ranging from tiny zooplankton to large marine mammals, seabirds, and fish. Says lead author Daniel Boyce, "Phytoplankton is the fuel on which marine ecosystems run. A decline of phytoplankton affects everything up the food chain, including humans."

                                                               

Southern Right whale off the coast of Hermanus; South Africa. Phytoplankton forms the basis of the marine food chain and sustains diverse assemblages of species ranging from tiny zooplankton to large marine mammals, seabirds, fish and certain whales. (Credit: iStockphoto)
                                                               
                               
Using an unprecedented collection of historical and recent oceanographic data, a team from Canada's Dalhousie University documented phytoplankton declines of about 1% of the global average per year. This trend is particularly well documented in the Northern Hemisphere and after 1950, and would translate into a decline of approximately 40% since 1950. The scientists found that long-term phytoplankton declines were negatively correlated with rising sea surface temperatures and changing oceanographic conditions.

The goal of the three-year analysis was to resolve one of the most pressing issues in oceanography, namely to answer the seemingly simple question of whether the ocean is becoming more (or less) „green' with algae. Previous analyses had been limited to more recent satellite data (consistently available since 1997) and have yielded variable results. To extend the record into the past, the authors analysed a unique compilation of historical measurements of ocean transparency going back to the very beginning of quantitative oceanography in the late 1800s, and combined these with additional samples of phytoplankton pigment (chlorophyll) from ocean-going research vessels. The end result was a database of just under half a million observations which enabled the scientists to estimate phytoplankton trends over the entire globe going back to the year 1899.

The scientists report that most phytoplankton declines occurred in polar and tropical regions and in the open oceans where most phytoplankton production occurs. Rising sea surface temperatures were negatively correlated with phytoplankton growth over most of the globe, especially close to the equator. Phytoplankton need both sunlight and nutrients to grow; warm oceans are strongly stratified, which limits the amount of nutrients that are delivered from deeper waters to the surface ocean. Rising temperatures may contribute to making the tropical oceans even more stratified, leading to increasing nutrient limitation and phytoplankton declines. The scientists also found that large-scale climate fluctuations, such as the El-Niño Southern Oscillation (ENSO), affect phytoplankton on a year-to-year basis, by changing short-term oceanographic conditions.

The findings contribute to a growing body of scientific evidence indicating that global warming is altering the fundamentals of marine ecosystems. Says co-author Marlon Lewis, "Climate-driven phytoplankton declines are another important dimension of global change in the oceans, which are already stressed by the effects of fishing and pollution. Better observational tools and scientific understanding are needed to enable accurate forecasts of the future health of the ocean." Explains co-author Boris Worm, "Phytoplankton are a critical part of our planetary life support system. They produce half of the oxygen we breathe, draw down surface CO2, and ultimately support all of our fisheries. An ocean with less phytoplankton will function differently, and this has to be accounted for in our management efforts."

Sumber: David A. Siegel & Bryan A. Franz. Oceanography: Century of phytoplankton change. Nature, July 28, 2010;  p569

dauswq

Global Tropical Forests Threatened by 2100

Tropical forests hold more then half of all the plants and animal species on Earth. But the combined effect of climate change, forest clear cutting, and logging may force them to adapt, move, or die. (Credit: iStockphoto/Sze Rei Wong)



                                                                                

ScienceDaily (Aug. 6, 2010) — By 2100 only 18% to 45% of the plants and animals making up ecosystems in global, humid tropical forests may remain as we know them today, according to a new study led by Greg Asner at the Carnegie Institution's Department of Global Ecology. The research combined new deforestation and selective logging data with climate-change projections. It is the first study to consider these combined effects for all humid tropical forest ecosystems and can help conservationists pinpoint where their efforts will be most effective. The study is published in the August 5, 2010, issue of Conservation Letters.

                                                                                                
"This is the first global compilation of projected ecosystem impacts for humid tropical forests affected by these combined forces," remarked Asner. "For those areas of the globe projected to suffer most from climate change, land managers could focus their efforts on reducing the pressure from deforestation, thereby helping species adjust to climate change, or enhancing their ability to move in time to keep pace with it. On the flip side, regions of the world where deforestation is projected to have fewer effects from climate change could be targeted for restoration."

Tropical forests hold more then half of all the plants and animal species on Earth. But the combined effect of climate change, forest clear cutting, and logging may force them to adapt, move, or die.

The scientists looked at land use and climate change by integrating global deforestation and logging maps from satellite imagery and high-resolution data with projected future vegetation changes from 16 different global climate models. They then ran scenarios on how different types of species could be geographically reshuffled by 2100.They used the reorganization of plant classes, such as tropical broadleaf evergreen trees, tropical drought deciduous trees, plus different kinds of grasses as surrogates for biodiversity changes.

For Central and South America, climate change could alter about two-thirds of the humid tropical forests biodiversity -- the variety and abundance of plants and animals in an ecosystem. Combining that scenario with current patterns of land-use change, and the Amazon Basin alone could see changes in biodiversity over 80% of the region.
Most of the changes in the Congo area likely to come from selective logging and climate change, which could negatively affect between 35% and 74% of that region. At the continental scale, about 70% of Africa's tropical forest biodiversity would likely be affected if current practices are not curtailed.

In Asia and the central and southern Pacific islands, deforestation and logging are the primary drivers of ecosystem changes. Model projections suggest that climate change might play a lesser role there than in Latin America or Africa. That said, the research showed that between 60% and 77%  of the area is susceptible to biodiversity losses via massive ongoing land-use changes in the region.

"This study is the strongest evidence yet that the world's natural ecosystems will undergo profound changes -- including severe alterations in their species composition -- through the combined influence of climate change and land use," remarked Daniel Nepstad, senior scientist at the Woods Hole Research Center. "Conservation of the world's biota, as we know it, will depend upon rapid, steep declines in greenhouse gas emissions."

The John D. and Catherine T. MacArthur Foundation and the Gordon and Betty Moore Foundation, support the Carnegie Landsat Analysis System, the Global Spectronomics project, and this study.

References: Carnegie Institution. "Global Tropical Forests Threatened by 2100." ScienceDaily 6 August 2010. 7 August 2010

dauswq

skrg pokok bukan sahaja diancam kerana pembalakan, malah dengan kesan rumah hijau juga menyebabkan penyusutan beberapa spesies pokok..

cth: pokok di kwsn pergunungan juga akn diancam kepupusan disebabkan  perubahan suhu mendadak

For Central and South America, climate change could alter about two-thirds of the humid tropical forests biodiversity -- the variety and abundance of plants and animals in an ecosystem.

tak lama lagi..kita tak dpt menikmati keindahan panorama hijau

winamp05

satu saja cara nak menangani masalah global warming nih, stop production seluruh donia, stop guna kenderaan bermotor. stop smoking. stop guna aircond.

Teringat citer The Day The Earth Stood Still.

dauswq

satu saja cara nak menangani masalah global warming nih, stop production seluruh donia, stop guna ke ...
winamp05 Post at 9-8-2010 08:56

yes indeed

p/s: abg winamp..dpt pm tak

dauswq

Sulfur stalls surface temperature rise


A new study demonstrates why global surface temperatures defied a decades-long trend and didn’t continue to rise between 1998 and 2008: Pollution-spewing, coal-burning power plants in Asia, while emitting warming greenhouse gases, simultaneously sent cooling sulfur particles into the atmosphere.

During that decade — sometimes cited as evidence to deny global warming — these Asian emissions mostly balanced one another and dampened the effects of natural cooling cycles associated with the sun and ocean temperatures.
A team of scientists led by Boston University’s Robert Kaufmann reached this conclusion by analyzing factors contributing to global surface temperature, including human-caused emissions, the 11-year solar cycle and a shift from warming El Niño to cooling La Niña climate patterns. Without human input, temperatures would have been expected to cool, based on the La Niña shift and decreasing solar radiation.


After simulating temperature change over the decade based on these factors, the researchers identified the smoking gun behind the steady temperatures: sulfur particles spit into the atmosphere by coal-burning power plants. Sulfur aerosols reflect light back into space and counteract the warming effects of greenhouse gases.


“This looks like a very solid, careful statistical analysis of the factors influencing recent global temperature changes,” says climate scientist Michael E. Mann of Pennsylvania State University, who was not involved in the study. “There is a clear impact of human activity on the ongoing warming of our climate.”

The study was published online July 5 in the Proceedings of the National Academy of Sciences.
Most of the greenhouse gases came from China, where coal consumption more than doubled between 2003 and 2007, accounting for 77 percent of the rise in coal use worldwide, the scientists report. During that same period, Kaufmann says, global sulfur emissions increased by 26 percent.

From 1998 to 2008, these human-generated emissions effectively canceled each other out.

“Humans do two things to the planet,” Kaufmann says. “They warm it by emitting greenhouse gases like carbon dioxide and methane, and they cool it by emitting these sulfur aerosols.”
(Manusia menyebabkan pengeluaran gas rumah hijau - CO2 & Methana tetapi mereka menyejukkannya dengan aerosol yg mengandungi sulfur)

Sending sulfur into the air isn’t helpful, though. In addition to causing respiratory problems, sulfur aerosols combine with water vapor to form acid rain, which harms ecosystems and damages buildings. “You wouldn’t want to increase the amount of junk in the air to decrease the effects of global warming,” cautions climate scientist Gavin Schmidt of NASA’s Goddard Institute for Space Studies in New York.

(Walaupun begitu, pengeluaran sulfur yg banyak bakal larut dalam air hujan menghasilkan hujan asid. Kita tak mgkn menghasilkan lebih byk sulfur utk mengurangkan kesan rumah hijau)

The researchers did a good job teasing apart the factors influencing global temperatures during the decade studied, Schmidt says. He compares global warming to driving a car: Humans are stepping on the accelerator, but bumps in the road vary the car’s speed. On shorter time scales, these bumps include things like the 11-year solar cycle and El Niño/Southern Oscillation events, both of which peaked early during the decade.

Because uncontrollable natural forces affect climate, it’s even more crucial to regulate human-produced greenhouse gas emissions, says Caspar Ammann, a climate scientist at the National Center for Atmospheric Research in Boulder, Colo. When sulfur emissions are reduced, “What you will see in the short term is a relative rapid rise in temperature, because you have taken away the brake,” Ammann says. Kaufmann says China has begun using scrubbers at its coal-burning facilities to reduce sulfur emissions — similar to what happened in the United States after passage of the Clean Air Act more than four decades ago.


Judith Curry of the Georgia Institute of Technology in Atlanta notes that decadal oscillations in ocean currents might be at least as likely to explain the observed stall in temperature rise as increased sulfur emissions from China.

But Kaufmann says that when sulfur is removed from the analysis, the model falls apart. “Only sulfur aerosols can explain the recent pattern,” he says. “Diminishing the importance of aerosols is inconsistent with the data.”


Gmbrjh menunjukkan gas sulfur yang dibebaskan oleh gunung berapi menyebabkan 2 kesan - menyejukkan semula kesan rumah hijau dgn memantulkan balik pancaran cahaya dan menghasilkan hujan asid pada masa yg sama

areenarena

kesian negara 4 musim.. nasib baek kite dah biasa dengan cuaca panas...alhamdulilah

dauswq

2011 was ninth-warmest year since 1880: NASA

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Posted 2012/01/19 at 4:44 pm EST

WASHINGTON, Jan. 19, 2012 (Reuters) —
The global average temperature last year was the ninth-warmest in the modern meteorological record, continuing a trend linked to greenhouse gases that saw nine of the 10 hottest years occurring since the year 2000, NASA scientists said on Thursday.

A separate report from the U.S. National Oceanic and Atmospheric Administration (NOAA) said the average temperature for the United States in 2011 as the 23rd warmest year on record.

The global average surface temperature for 2011 was 0.92 degrees F (0.51 degrees C) warmer than the mid-20th century baseline temperature, researchers at NASA's Goddard Institute for Space Studies said in a statement. The institute's temperature record began in 1880.

The first 11 years of the new century were notably hotter than the middle and late 20th century, according to institute director James Hansen. The only year from the 20th century that was among the top 10 warmest years was 1998.

These high global temperatures come even with the cooling effects of a strong La Nina ocean temperature pattern and low solar activity for the past several years, said Hansen, who has long campaigned against human-spurred climate change.
The NASA statement said the current higher temperatures are largely sustained by increased concentrations of greenhouse gases in the atmosphere, especially carbon dioxide. Carbon dioxide is emitted by various human activities, from coal-fired power plants to fossil-fueled vehicles to human breath.

Current levels of carbon dioxide in the atmosphere exceed 390 parts per million, compared with 285 ppm in 1880 and 315 by 1960, NASA said.

Last year was also a year of record-breaking climate extremes in the United States, which contributed to 14 weather and climate disasters with economic impact of $1 billion or more each, according to NOAA. This number does not count a pre-Halloween snowstorm in the Northeast, which is still being analyzed.

NOAA's National Climatic Data Center said the average 2011 temperature for 2011 for the contiguous United States was 53.8 degrees F, which is 1 degree above the 20th-century average. Average precipitation across the country was near normal, but this masks record-breaking extremes of drought and precipitation, the agency said.
(Reporting By Deborah Zabarenko, Environment Correspondent; Editing by Xavier Briand)

dauswq

tahun 1998 tu mmg plg panas ke? sbb volcanic eruption + jerebu kan?

midory

tahun 1998 tu mmg plg panas ke? sbb volcanic eruption + jerebu kan?
dauswq Post at 24-1-2012 12:49

   aku ade terbace yg tahun 1998 tu bukan paling panas tp tahun 1934.. sebab ade kesilapan mase nasa rekod data.