Weather

Scientists from the University of Manchester have shown that natural emissions and humanmade pollutants can both have an unexpected cooling effet on Earth's climate by making clouds brighter.

Clouds are composed of water droplets that are condensed onto tiny particles suspended in the air. When the air is humid enough, the particles swell into cloud droplets. Researchers have known for some decades that the number of these particles and their size control how bright the clouds appear from the top, which controls the efficiency with which clouds scatter sunlight back into space.

One of the major challenges for climate scientists is to understand and quantify these effects, which have major effects in polluted areas of the world.

The tiny seed particles can either be natural from things like sea spray or dust, or humanmade pollutants from things like vehicle exhaust or industrial activity. These particles ofte contain a large amount of organic material and are quite volatile compounds, so in warm conditions they exist as a vapor.

Researchers have found that the effect acts in reverse in the atmosphere as the volatile organic compounds from pollution or from the biosphere evaporates and give off characteristic aromas.However, under moist, cooler conditions where clouds form, the molecules prefer to be liquid and make larger particles that are more effective seeds for cloud droplets.

According to a new study, from 1971 to 2000, the Earth's land areas were the warmest they have been in at least 1,400 years.

The new study, which was published in Nature Geoscience, was a massive undertaking involving 80 researchers from around the world with the Past Global Changes (PAGES) group. It is considered to be the first study to look at continental temperature changes over two thousand years, which gives insight into regional climatic changes from the Roman Empire to modern day.

According to the data, Earth's land masses were generally cooling until anthropogenic climate change reversed the long-term pattern during the late 19th century.

Co-author Ulf Büntgen with the Swiss Federal Research Institute (WSL) and PAGES noted:

"Even just a few years ago we would have aimed for a single worldwide temperature series. Nowadays, we know how important it is to have a better understanding of regional differences."

The scientists were able to reconstruct continental temperatures across every continent with the exception of Africa, where data is still lacking. They discovered that continents could still show important idiosyncrasies in the midst of global trends. Co-author Heinz Wanner of the University of Bern and PAGES member commented:

"Distinctive periods, such as the Medieval Warm Period or the Little Ice Age stand out, but do not show a globally uniform pattern."

The National Oceanic and Atmospheric Administration (NOAA) Drought Task Force recently released a study which found that the 2012 Great Plains drought, the worst on record in the U.S. since record keeping began in 1895, was not the result of climate change. Instead, the NOAA says that the drought was the result of "natural variations in weather patterns" and not "human-induced climate change."

The 2012 drought affected the states of Wyoming, Colorado, Kansas, Nebraska, South Dakota, and North Dakota. It had previously been blamed on climate change.

Dr. Martin Hoerling, senior author of the new report, "An interpretation of the Origins of the 2012 Central Plains Drought", said that while he is an "advocate of global warming...the science also tells that every drought that is occurring isn't a result of climate change."

The massive asteroid impact that is thought to have wiped out the dinosaurs 65 million years ago may have also light up the Earth's skies red and sparked a cataclysmic global firestorm.

The mass die-off known as the K-T extinction is believed by most scientists to have been caused by an asteroid or comet that impacted the Earth and created the 112-mile-wide Chicxulub crater in Mexico. This extinction event resulted in the vanishing of up to 80 percent of Earth's species.

Researchers have created a new model of the disaster, and now say that the impact would have sent vaporized particles of rock high above Earth's atmosphere, where they would have condensed into sand-grain size pieces. As the hot, ejected rock material fell back to Earth, it could have dumped enough heat in the upper atmosphere to cause it cook at 2,700 degrees Fahrenheit, which would have turned the sky red for several hours.

The infrared "heat pulse" would have behaved like a broiler oven, igniting tinder below and burning every twig, bush, tree and any living thing not shielded underground or underwater.

Douglas Robertson of the Cooperative Institute for Research in Environmental Sciences, explains:

"It's likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth."

Researchers note that a 1-megaton hydrogen bomb would be the equivalent of 80 Hiroshima-type nuclear bombs. The Chicxulub event is thought to have produced about 100 million megatons of energy.

A new study has found that global warming will make it difficult to raise grapes in traditional wine country, which will force production to shift to other regions. The study has found sharp declines in wine production from Bordeaux, Rhone, Tuscany, California's Napa Valley, and Chile by 2050 as warming climates make it harder to raise grapes in traditional wine country.

Researchers are now predicting a two-thirds fall in production in the world's premier wine regions due to climate change, with the biggest decline expected in Europe. However, they also anticipate that wine production will make a large push into areas that were once considered unsuitable for wine making, which could mean a greater variety from northern Europe, the northwest U.S., and even the hills of central China.

Lee Hannah, a senior scientist at Conservation International and an author of the study, says:

"The fact is that climate change will lead to a huge shakeup in the geographic distribution of wine production."

Researchers are anticipating huge changes in the regions that produce good grapes. Hannah notes:

"It will be harder and harder to grow those varieties that are currently growing in places in Europe. It doesn't necessarily mean that [they] can't be grown there, but it will require irrigation and special inputs to make it work, and that will make it more and more expensive."

One of the most finicky varieties of grapes are white grapes, which are sensitive to very subtle temperature shifts, rain, and sunshine.

Over the past 44 years, flights have become bumpier. According to a new study, they're now set to get even worse as climate change affects the jet stream. An analysis by scientists of the impact of global warming on weather systems over the next four decades reveals that climate change will lead to bumpier flights caused by increased mid-air turbulence.

The increased air turbulence is a result of the impact of climate change on the jet streams, which are the mile-wide winds that swirl around the planet at the same altitude as airplanes.

Some of the other unexpected impacts of climate change include spottier WiFi and mobile phone signals, and even slower marathon race times for runners.

The new research was led by Paul Williams at the University of Reading, who states:

"Air turbulence does more than just interrupt the service of in-flight drinks. It injures hundreds of passengers and aircrew every year. It also causes delays and damages planes, with the total cost to society being about £100m each year."

Williams found that the frequency of turbulence on the numerous flights between North America and Europe will double by 2050. It's intensity will also increase by 10 to 40%.

5,000 years ago, the climate shift in North Africa was quite dramatic and sudden. It transformed from lakes and grasslands with hippos and giraffes, to a vast, dry desert. A new study finds that the sudden geographic transformation took place nearly simultaneously across the continent's northern half.

These findings come from the analysis of dust blown west from Africa and dropped into the Atlantic Ocean. Researchers sifted through 30,000 years worth of dust and ocean bottom muck that was retrieved by ocean drilling ships. The changing levels of windblown dust in ocean sediments are what have provided scientists with clues to Africa's climate, and how it has changed over time.

In simple terms, a lot of dust meant drier conditions and less dust meant a wetter environment.

The west period in northern Africa is known as the African Humid Period. This period of wetness both started and ended suddenly. The Humid Period ended abou 6,000 years ago, and dust levels were at about 20 percent of today's, which is much less dusty than previous estimates. This suggests that the change in climate was rather dramatic.

NASA scientist James E. Hansen, one of the nation's leading climate scientists, announced on Tuesday that he will be retiring. Hansen, however, will not be sitting idle for long. Now that he will soon no longer be employed by the U.S. government, he's going to pursue one of his longtime passions and help climate activists suing the federal government.

Hansen was a pioneering climate researcher for the government for 46 years, and was one of the first to warn the world about the causes and effects of an increasingly warmer planet. In recent years, he has shifted more towards activism, which has both concerned his colleagues and opponents because they believe that his protests undermine the value of scientific neutrality.

April will fortunately not be as cold as March, but it's not expected to be very warm either. According to Accuweather, pockets of cold air will continue to invade from the northern Plains to the Midwest and Northeast into the first half of April, dashing hopes of a break from the snow and cold those areas are currently enduring.

The overall weather patten into the first part of April will continue to be about a month behind schedule. March was like a typical February, and Accuweather says that the first half of April will be what March should have been like.

The kind of weather that we can expect from now to mid-April is a bit of a mixed bag. It's likely to include strings of chilly, unsettled days with clouds and showers, or days when it starts off sunny but then brings clouds and thunderstorms with hail. Additional heavy, wet lake effect snow is not even out of the realm of possibility for the Great Lakes area to the central Appalachians.

Fortunately, long-range meteorlogists are expecting that the atmosphere will begin to behave more like it should be for this time of year from the northern Plains to the Midwest and Northeast

With temperatures hovering in the low-to-mid-20's here in Northeast Ohio and elsewhere just one day into Spring, it's hard to believe that spring has actually arrived. Even more difficult to imagine is the prediction that spring may even turn out to be warmer than normal throughout much of the United States. The National Weather Service contends that that majority of the U.S. will experience above-average temperatures over the next three months.

Laura Furgione made these predictions about spring during the National Oceanographic and Atmospheric Administration's spring climate outlook briefing held Thursday morning.

In addition to the warmer temperatures, drought is also expected to continue or even worse in much of the Southwest and central plains. Furgione added that 51 percent of the U.S. is in moderate or worse drought, also stating:

"We expect it to be drier than normal in much of the West, Rockies and Southwest, including Texas, which is unfortunate since we're looking at continued drought there."

Despite the drought in some areas of the country, flooding is likely in some regions, with the most severe possibilities occuring in North Dakota along the Red River. The upper and middle Mississippi River valley could also see some flooding, which may be worsened by melting of late season snow.