Global Warming
What is Global Warming aka Climate Change?
Global warming is the increase of the average temperature in the atmosphere and oceans over time due primarily to human influences. Since the late 19th century, scientists have monitored the fluctuations in temperature and studied global warming theories and trends to determine the causes and to assess the extent to which they are due to human activity. The greenhouse effect is largely caused by human-generated carbon dioxide (CO2) and, to some extent, by increases in solar activity. The term "global warming" is used to imply a human influence while "climate change" is most often used in association with changes in climate with no easily identifiable cause, such as the processes that produced the Ice Ages.
Current climate models (simulations) based on estimates of increasing CO2 and, to a lesser extent, by decreasing sulfate aerosols, predict that temperatures will increase by 1.4-5.8°C (2.5-10.4°F) between 1990-2100. This is a somewhat wide range; however, it is difficult to predict CO2 emissions because of the number of variables involved. Some climate studies have shown that, even in the absence of the CO2 emission variable, global climate will increase by 0.5°C (0.9°F) over the next one hundred years due to warming caused just by the ocean. In addition, models predict that sea levels will rise by about 10 cm over the next century.
Evidence of global warming includes decreased snowfall, rising sea levels and changes to weather trends. Precipitation levels, precipitation patterns, cloud cover, severe weather, and other elements will be impacted by the increase in greenhouse gas concentrations in the atmosphere. "Greenhouse gases" are so named because they trap radiant energy from the sun that would otherwise be radiated back into space.
The Kyoto Protocol was developed by the United Nations Framework Convention on Climate Change (UNFCCC) as an international agreement to reduce greenhouse gas emissions worldwide. The Protocol was entered into force in February 2005, and signed by countries committed to reducing CO2 emissions and 5 other greenhouse gases. They may also engage in emissions trading, or the purchase of credits from other countries that remain under the limits of greenhouse gas emissions. In this way, countries that may exceed the limits can still comply with the protocol. To date, 141 countries have ratified the agreement. Unfortunately, neither the United States nor Australia have been participating, which has generated speculation as to whether the Kyoto Protocol will successfully reduce greenhouse gases, even if completely implemented by all signed countries.
Global climate change has been studied on a large scale based on analyses of global temperature fluctuations over thousands of years; for example, since the last Ice Age, which occurred approximately 12,000 years ago, global temperatures have been relatively stable. Studies on a smaller scale, however, show that temperatures in the lower troposphere have increased between 0.08 and 0.22°C per decade since 1979. Still, these modern day changes are not always linear, which has created a source of debate within the scientific community and the news media.
The study of paleoclimatology (ancient climates) is increasingly linked to modern day climate study. For example, the Earth was in an ice age for the last 160,000 years prior to the end of the last Ice Age. Earlier studies of this time period showed little variability in temperatures; however, more recent studies showed the variability to be about twice as great as previously published, indicating that temperature fluctuations are more frequent throughout time than first thought. However, this does not negate the impact of human activity on the current rate of global warming.
Climate change is caused by both natural and external forces, the latter including both human—greenhouse gases—and non-human causes such as changes in the Earth's orbit around the Sun, solar activity, and volcanic emissions. Science is increasingly pointing to human activities as the reason that global warming is accelerating.
The greenhouse gas theory started in the 19th century when the Swedish chemist and 1903 Nobel Laureate, Svante Arrhenius, determined that increases in greenhouse gas concentration would lead to higher global mean temperatures, while decreases would lead to colder global mean temperatures. His finding was a result of his research on ice ages, and was largely rejected by his peers at the time. A colleague of Arrhenius, Arvid Högbom, was one of the first scientists to study the carbon cycle. Arrhenius used his data to base his assessment that in 1890, emission and absorption of CO2 in the atmosphere were roughly in balance, and that burning fossil fuels would not cause problems. However, this was based solely on the use of coal, not on the use of fossil fuels in the automobile and other industries.
Opponents to the global warming theory postulate that water vapor and clouds will cancel out warming effect of CO2 emissions. However, the warming trends over the past few decades are increasingly negating the cancellation hypothesis. Furthermore, sophisticated computer models of the climate, validated by the scientific community in demonstrating accurate simulations of known climate variations such as El Niño events, have predicted that adding CO2 to the atmosphere will create a warmer climate in the future. The degree to which this warming will occur varies by model, however, and opponents of the global warming theory point out variables that models are not equipped to factor, such as changes in vegetation and cloud cover.
In spite of the dying debate, it is known that coal-burning power plants, automobile exhausts, factory smokestacks, and other waste vents contribute about 22 billion tons of CO2 (6 billion tons of pure carbon) and other greenhouse gases into the earth's atmosphere each year. CO2 levels have increased by about 31% since 1750, about 75% of which can be attributed to fossil fuel burning. The remaining 25% is largely due to land-use change, particularly deforestation.
In their 2006 report, the IPCC stated that the atmospheric concentration of CO2 has exceeded levels over the natural range for the last 650,000 years. The consensus is that human activity is, in almost all aspects of global warming, the most likely cause. This is a change from the previous report that stated human activity was merely a likely cause.
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Global Warming News :: ScienceDailyMajor study of ocean acidification helps scientists evaluate effects of atmospheric carbon dioxide on marine life
Might a penguin's next meal be affected by the exhaust from your tailpipe? The answer may be yes, when you add your exhaust fumes to the total amount of carbon dioxide lofted into the atmosphere by humans since the industrial revolution. One-third of that carbon dioxide is absorbed by the world's oceans, making them more acidic and affecting marine life.
Carbon dioxide is 'driving fish crazy'
Rising human carbon dioxide emissions may be affecting the brains and central nervous system of sea fishes with serious consequences for their survival, an international scientific team has found. Carbon dioxide concentrations predicted to occur in the ocean by the end of this century will interfere with fishes' ability to hear, smell, turn and evade predators, says a professor.
Multiple partners not the only way for corals to stay cool
For the first time scientists have shown that corals hosting a single type of zooxanthellae can have different levels of thermal tolerance -– a feature that was only known previously for corals with a mix of zooxanthellae. This finding is important because many species of coral are dominated by a single type of zooxanthellae.
Ecologists gain insight into the likely consequences of global warming
A new insight into the impact that warmer temperatures could have across the world has been uncovered by scientists.
Biodiversity crisis is worse than climate change, experts say
Biodiversity is declining rapidly throughout the world. The challenges of conserving the world's species are perhaps even larger than mitigating the negative effects of global climate change, experts say.
NASA finds 2011 ninth-warmest year on record
The global average surface temperature in 2011 was the ninth warmest since 1880, according to NASA scientists. The finding continues a trend in which nine of the 10 warmest years in the modern meteorological record have occurred since the year 2000.
NASA sees repeating La Niña hitting its peak
La Niña, "the diva of drought," is peaking, increasing the odds that the Pacific Northwest will have more stormy weather this winter and spring, while the southwestern and southern United States will be dry. Sea surface height data from NASA's Jason-1 and -2 satellites show that the milder repeat of last year's strong La Niña has recently intensified, as seen in the latest Jason-2 image of the Pacific Ocean.
Hearty bacteria help make case for life in the extreme
The bottom of a glacier is not the most hospitable place on Earth, but at least two types of bacteria happily live there, according to researchers.
Food security road map while adapting to climate change
While recent climate negotiations in Durban made incremental progress toward helping farmers adapt to climate change and reduce agriculture's climate footprint, a group of international agriculture experts urges scientists to lay the groundwork for more decisive action on global food security in environmental negotiations in 2012.
Toward twister forecasting: Scientists make progress in assessing tornado seasons
A new study of short-term climate trends offers the first framework for predicting tornado activity up to a month out with current technology, and possibly further out as climate models improve, giving communities a chance to plan. The study may also eventually open a window on the question of whether tornadoes are growing more frequent due to long-term climate warming.
Low temperatures enhance ozone degradation above the Arctic
Extraordinarily cold temperatures in the winter of 2010/2011 caused the most massive destruction of the ozone layer above the Arctic so far: The mechanisms leading to the first ozone hole above the North Pole have now been investigated.
Climate change invites alien invaders: Is Canada ready?
A comprehensive multi-disciplinary synthesis reveals the urgent need for further investigation and policy development to address significant environmental, social and economic impacts of invasive alien species and climate change.
Impact of land use activity in the Amazon basin evaluated
Portions of the Amazon basin are experiencing a transition in energy and water cycles. Evidence suggests that the Amazon may also be transitioning from a net carbon sink to a net source. This research shows that although the Amazon is resilient to individual disturbances, such as drought, multiple disturbances override this, increasing the vulnerability of forest ecosystems to degradation. This review provides a framework for understanding the associations between natural variability and drivers of change.
Climate balancing: Sea-level rise vs. surface temperature change rates
Engineering our way out of global climate warming may not be as easy as simply reducing the incoming solar energy, according to a climate scientists. Designing the approach to control both sea level rise and rates of surface air temperature changes requires a balancing act to accommodate the diverging needs of different locations.
Butterflies and birds unable to keep pace with climate change in Europe
Butterflies and birds are no longer able to keep up with climate change. Compared with 20 years ago, butterflies are now 135 kilometers behind the shifting climate zones and birds more than 200 kilometers, according to findings of a new study.
Evidence of past Southern hemisphere rainfall cycles related to Antarctic temperatures
Geoscientists have published the first evidence that warm-cold climate oscillations well known in the Northern Hemisphere over the most recent glacial period also appear as tropical rainfall variations in the Amazon Basin of South America. It is the first clear expression of these cycles in the Southern hemisphere.
Ice age findings forecast problems: Data from end of last Ice Age confirm effects of climate change on oceans
The first comprehensive study of changes in the oxygenation of oceans at the end of the last Ice Age has implications for the future of our oceans under global warming. The study looked at marine sediment and found that that the dissolved oxygen concentrations in large parts of the oceans changed dramatically during the relatively slow natural climate changes at the end of the last Ice Age.
Biodiversity enhances ecosystem multifunctionality in global drylands
Scientists have finished a global empirical study that suggests that preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.
Engineering team completes ambitious Antarctic expedition in the 'deep-field'
A team of four British engineers has returned to the UK after completing a grueling journey to one of the most remote and hostile locations on the planet to put in place equipment and supplies for an ambitious project later this year. Enduring temperatures of minus 35 C the Subglacial Lake Ellsworth "Advance Party" has successfully paved the way to explore an ancient lake buried beneath 3 km of Antarctic ice.
Climate change currently benefits albatrosses
Due to climate change, wind patterns are changing in the Southern Ocean. Higher wind speeds enable the wandering albatrosses of the Crozet Islands to travel more rapidly in search of food.The phenomenon has modified the distribution of these seabirds and improved their physical condition as well as their breeding success.
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