Environmental Changes May Affect Vital Cooperate Bird Behaviors

While scientists believe that climate change and related extreme weather events such as drought and flooding will likely affect the earth's flora and fauna, just how much is not known. A new study by researchers Walter Jetz from Yale University and Dustin Rubenstein from Columbia University however shows an important link between the natural variation in climate conditions and complex behaviors among birds.
The study, which appears in print in Current Biology on Jan. 11, 2011, has implications for understanding how organisms may respond behaviorally to increased climate variability resulting from climate change. They argue that species that live in families may be better guarded against the effects of unpredictable climatic conditions.
Family-living, or cooperative breeding, is common among birds. Cooperative breeding societies, such as humans, are typically characterized by groups of relatives that work together to raise young. Usually, some birds forgo their own reproduction to help raise others' offspring. However, some cooperative breeding societies consist of groups of non-relatives that also work together in raising young. From Australia to the Amazon, cooperatively breeding birds account for approximately 831 species -- or nearly 10 percent -- of the nearly 10,000 avian species worldwide.
Using a behavioral data set of more than 95 percent of the world's birds, and a global 40-year climate dataset, the researchers examined how environmental factors -- like mean and variation in temperature and rainfall -- and biotic factors -- like body mass, diet breadth and type -- influence the incidence and global distribution of family-living in birds.
"Scientists have long known that family-living birds are more common in some parts of the world than others," said Rubenstein, assistant professor of ecology, evolution & environmental biology. "But this is the first time that we have been able to study the geographic distribution of complex avian social behavior on a global scale, while simultaneously examining how the environment influences these geographic patterns."
By combining behavioral and climate data in a statistical modeling framework the researchers found dramatic spatial and environmental variation in social behavior globally. "We discovered 'hot-spots' in places like Australia and Africa where family-living species are overrepresented, as well as 'cold-spots' in places like South and Central America where there are fewer family-living species than we would have expected," said Jetz. This geographic unevenness coincided with the occurrence of specific bird lineages, but also carried a strong signal of environmental and biotic factors. In particular, among year variation, or climatic uncertainty, in rainfall emerged as a key predictor of family-living in birds.
The study demonstrates that even on a global scale, the incidence of complex avian social behavior may be greatly influenced by the consequences of living in unpredictable environments. Variable environments encompass a broad range of climate conditions that pose a greater range of challenges to survival and reproduction than predictable ones. Family-living among birds may therefore be a conservative "'best of a bad job'' strategy to maximize fitness when breeding conditions vary unpredictably from year to year.
"Families act as insurance against environmental uncertainty," said Rubenstein. "Just as predicting a drop in the stock market is difficult, so too is determining when food is going to be scarce." When times are bad and food is difficult to find, joining up to raise young may pay off for both parents and helpers.
This thinking may have implications for an entirely different group of animals: humans. "Think twice," cautions Rubenstein, "before you kick your grown kids out of the house, as you never know when you might need them."

This information is taken from- http://www.sciencedaily.com/releases/2011/01/110111150850.htm

Greenhouse Effect ...

The greenhouse effect is the rise in temperature that the Earth experiences because certain gases in the atmosphere (water vapor, carbon dioxide, nitrous oxide, and methane, for example) trap energy from the sun. Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder. Because of how they warm our world, these gases are referred to as greenhouse gases.

Have you ever seen a greenhouse? Most greenhouses look like a small glass house. Greenhouses are used to grow plants, especially in the winter. Greenhouses work by trapping heat from the sun. The glass panels of the greenhouse let in light but keep heat from escaping. This causes the greenhouse to heat up, much like the inside of a car parked in sunlight, and keeps the plants warm enough to live in the winter. The Earth’s atmosphere is all around us. It is the air that we breathe. Greenhouse gases in the atmosphere behave much like the glass panes in a greenhouse. Sunlight enters the Earth's atmosphere, passing through the blanket of greenhouse gases. As it reaches the Earth's surface, land, water, and biosphere absorb the sunlight’s energy. Once absorbed, this energy is sent back into the atmosphere. Some of the energy passes back into space, but much of it remains trapped in the atmosphere by the greenhouse gases, causing our world to heat up. (D) The greenhouse effect is important. Without the greenhouse effect, the Earth would not be warm enough for humans to live. But if the greenhouse effect becomes stronger, it could make the Earth warmer than usual. Even a little extra warming may cause problems for humans, plants, and animals.

This information is taken from- http://epa.gov/climatechange/kids/greenhouse.html

Global Warming Could Cool Down Northern Temperatures in Winter

The overall warming of Earth's northern half could result in cold winters, new research shows. The shrinking of sea-ice in the eastern Arctic causes some regional heating of the lower levels of air -- which may lead to strong anomalies in atmospheric airstreams, triggering an overall cooling of the northern continents, according to a study recently published in the Journal of Geophysical Research.

"These anomalies could triple the probability of cold winter extremes in Europe and northern Asia," says Vladimir Petoukhov, lead author of the study and climate scientist at the Potsdam Institute for Climate Impact Research. "Recent severe winters like last year's or the one of 2005-06 do not conflict with the global warming picture, but rather supplement it."
The researchers base their assumptions on simulations with an elaborate computer model of general circulation, ECHAM5, focusing on the Barents-Kara Sea north of Norway and Russia where a drastic reduction of ice was observed in the cold European winter of 2005-06. Those surfaces of the sea lacking the ice cover lose a lot of warmth to the normally cold and windy arctic atmosphere. What the researchers did was to feed the computer with data, gradually reducing the sea ice cover in the eastern Arctic from 100 percent to 1 percent in order to analyse the relative sensitivity of wintertime atmospheric circulation.
"Our simulations reveal a rather pronounced nonlinear response of air temperatures and winds to the changes of sea-ice cover," Petoukhov, a physicist, says. "It ranges from warming to cooling to warming again, as sea ice decreases." An abrupt transition between different regimes of the atmospheric circulation in the sub-polar and polar regions may be very likely. Warming of the air over the Barents-Kara Sea seems to bring cold winter winds to Europe. "This is not what one would expect," Petoukhov says. "Whoever thinks that the shrinking of some far away sea-ice won't bother him could be wrong. There are complex teleconnections in the climate system, and in the Barents-Kara Sea we might have discovered a powerful feedback mechanism."
Other approaches to the issue of cold winters and global warming referring to reduced sun activity or most recently the gulf stream "tend to exaggerate the effects," Petoukhov says. The correlation between these phenomena and cold winters is relatively weak, compared to the new findings referring to the processes in the Barents-Kara Sea. Petoukhov also points out that during the cold winter of 2005-06 with temperatures of ten degrees below the normal level in Siberia, no anomalies in the north Atlantic oscillation have been observed. These are fluctuations in the difference of atmospheric pressure between the Icelandic low and the Azores high which are commonly associated with temperature anomalies over Europe. But temperatures in the eastern arctic were up to 14 degrees above normal level. However, distinct anomalies in the north Atlantic oscillation could interact with sea-ice decrease, the study concludes. One could amplify the other and more anomalies would be the result.
Petoukhov's study is not about tomorrow's weather forecast but about longtime probabilities of climate change. "I suppose nobody knows," he says, "how harsh this year's winter will be."
This article is taken from- http://www.sciencedaily.com/releases/2010/11/101117114028.htm

Doomsday Messages About Global Warming Can Backfire, Study Shows

Dire or emotionally charged warnings about the consequences of global warming can backfire if presented too negatively, making people less amenable to reducing their carbon footprint, according to new research from the University of California, Berkeley.

"Our study indicates that the potentially devastating consequences of global warming threaten people's fundamental tendency to see the world as safe, stable and fair. As a result, people may respond by discounting evidence for global warming," said Robb Willer, UC Berkeley social psychologist and coauthor of a study to be published in the January issue of the journal Psychological Science.
"The scarier the message, the more people who are committed to viewing the world as fundamentally stable and fair are motivated to deny it," agreed Matthew Feinberg, a doctoral student in psychology and coauthor of the study.
But if scientists and advocates can communicate their findings in less apocalyptic ways, and present solutions to global warming, Willer said, most people can get past their skepticism.
Recent decades have seen a growing scientific consensus on the existence of a warming of global land and ocean temperatures. A significant part of the warming trend has been attributed to human activities that produce greenhouse gas emissions.
Despite the mounting evidence, a Gallup poll conducted earlier this year found that 48 percent of Americans believe that global warming concerns are exaggerated, and 19 percent think global warming will never happen. In 1997, 31 percent of those who were asked the same question in a Gallup poll felt the claims were overstated.

In light of this contradictory trend, Feinberg and Willer sought to investigate the psychology behind attitudes about climate change.
In the first of two experiments, 97 UC Berkeley undergraduates were gauged for their political attitudes, skepticism about global warming and level of belief in whether the world is just or unjust. Rated on a "just world scale," which measures people's belief in a just world for themselves and others, participants were asked how much they agree with such statements as "I believe that, by and large, people get what they deserve," and "I am confident that justice always prevails over injustice."
Next, participants read a news article about global warming. The article started out with factual data provided by the United Nations Intergovernmental Panel of Climate Change. But while half the participants received articles that ended with warnings about the apocalyptic consequences of global warming, the other half read ones that concluded with positive messages focused on potential solutions to global warming, such as technological innovations that could reduce carbon emissions.
Results showed that those who read the positive messages were more open to believing in the existence of global warming and had more faith in science's ability to solve the problem. Moreover, those who scored high on the just world scale were less skeptical about global warming when exposed to the positive message. By contrast, those exposed to doomsday messages became more skeptical about global warming, particularly those who scored high on the just world scale.
In the second experiment, involving 45 volunteers recruited from 30 U.S. cities via Craigslist, researchers looked specifically at whether increasing one's belief in a just world would increase his or her skepticism about global warming.
They had half the volunteers unscramble sentences such as "prevails justice always" so they would be more likely to take a just world view when doing the research exercises. They then showed them a video featuring innocent children being put in harm's way to illustrate the threat of global warming to future generations.
Those who had been primed for a just world view responded to the video with heightened skepticism towards global warming and less willingness to change their lifestyles to reduce their carbon footprint, according to the results.
Overall, the study concludes, "Fear-based appeals, especially when not coupled with a clear solution, can backfire and undermine the intended effects of messages."
This article is taken from- http://www.sciencedaily.com/releases/2010/11/101117094248.htm