| |
| |
| New Universe: Archives | Important Information: Status Report To Advertise Here: Information | Universe Related |
|
The Environment: Related Pages.
Anthropogenic factors are acts by humans that change the environment and influence climate.
Nov 1, 2005 - Scientists at the Lawrence Livermore National Laboratory have developed a detailed model of the Earth's climate over the next few centuries to answer the question... what if we burned all the fossil fuels by the year 2300. The answer, of course, isn't a pretty picture. In their model, global temperatures will rise 8-degrees Celsius (14.5 F), and melting polar caps will raise the oceans 7 metres (23 feet). The damage would be even worse in the polar regions, which could grow by 20-degrees C (68 F). Oct 7, 2005 - Researchers from NASA have confirmed that it would have been impossible for advanced life forms, like fish or mammals, to live in the Earth's early oceans because it was such a toxic environment. The scientists studied ancient rock formations, and found evidence of photosynthetic bacteria living as recently as 1.6 billion years ago. This bacteria would have required both sunlight and an environment rich in hydrogen sulfide - this environment would have been quite toxic for air breathing creatures. Number of Powerful Hurricanes Has Doubled Sep 20, 2005 - Think there are more hurricanes these days? Well, you're right. In the last 35 years, meteorologists have recorded that the number of powerful category 4 and 5 hurricanes has doubled. In the 1970s, there were approximately 10 category 4/5 storms globally each year. In 2004 there were 18. The trend is happening because global sea temperatures have risen over the last half century. Powerful hurricanes in the North Atlantic, such as Hurricane Katrina, have increased at an even faster rate. More Sunlight is Hitting the Earth May 6, 2005 - The amount of sunlight reaching the Earth's surface has been on the rise for the past decade on average, potentially accelerating the effects of global warming. Scientists had been measuring a decrease in sunlight from the 1960s to the 1990s, because of rising pollution was actually blocking sunlight. With better pollution controls in place, the planet's surface has brightened by about 4% in the last 10 years. History of the Earth's Atmosphere Written in Rocks May 5, 2005 - Geologists have built up a suite of tools and techniques that let them peer back in time to watch the formative stages of the Earth and how it's changed over time - by looking inside rocks. By analyzing trapped water and air in rocks, geologists are studying how our atmosphere changed 3.9 billion years ago, when the crust of the planet was just forming, and there wasn't any oxygen in the air. Low Oxygen Accelerated the Great Dying Apr 19, 2005 - The biggest mass extinction in the Earth's history happened approximately 250 million years ago. During the "Great Dying", more than 90% of creatures in the ocean, and 75% of life on land went extinct. What caused the extinction is still up for debate, but a researcher from the University of Washington thinks that low levels of oxygen in the atmosphere sure didn't help. Oxygen went down to 12% (currently it's 21%), and this made standing at sea level the same as being atop a 5,300 metre mountain (17,000 feet). First Global Map of Methane Emissions Mar 18, 2005 - The European Space Agency's Envisat has completed a map of global methane emissions, and not surprisingly, areas of dense population show the highest levels of this greenhouse gas. What is a surprise, however, is that there are higher emissions than anticipated over tropical areas of the planet. This could be because of burning, termites, animals, or just increased decomposition of plants. Methane gas traps 21 times more heat per molecule than carbon dioxide, so it's important to locate these sources and limit them. Did Clouds in Space Cause Snowball Earth? Mar 4, 2005 - Scientists are fairly certain that the Earth went through a snowball glaciation 600-800 million years ago, when the entire planet was locked in snow and ice. One new theory to explain this extreme cooling is the possibility that the Solar System passed through an interstellar cloud of dust and gas, which obscured the light from the Sun. Even if the cloud wasn't thick enough to obscure light from the Sun, it could have enabled charged particles to pass into the Earth's atmosphere and destroy the ozone layer. These clouds are huge, and it would take the Solar System 500,000 years to pass through one. Air Pollution Linked to Growth of Life in Oceans Feb 11, 2005 - Researchers from the Georgia Institute of Technology have uncovered a surprising link between air pollution levels over land, and the growth of phytoplankton in the ocean. These tiny, but hardworking, aquatic plants carry out half the Earth's photosynthesis, and are responsible for removing tremendous quantities of carbon dioxide from the atmosphere. Normal dust storms produce iron which the phytoplankton can't use, but when it's modified by sulfur dioxide pollution, the iron becomes soluble and can trigger phytoplankton growth. Did Volcanoes Cause the Great Dying? Jan 21, 2005 - Something wiped out most of the life on Earth 250 million years ago. Evidence has been building that it was an asteroid or comet strike that made Earth unlivable nearly instantly. But other scientists think that it wasn't instantaneous; instead, they found fossil evidence that the extinction occurred over the course of 10 million years. A group of volcanoes in Siberia spewed out gas continuously that set off a runaway greenhouse effect. Lowered oxygen levels in the atmosphere combined with intense heat would have hit life a deadly double blow. Worldwide Pollution Levels Seen From Space Oct 12, 2004 - After 18 months of observations by the Envisat Earth monitoring satellite, the European Space Agency has produced a detailed image of the entire Earth that shows nitrogen dioxide pollution. Nitrogen dioxide is generally a man-made gas - produced in power plants, heavy industry, and burning - which can cause lung disease and respiratory problems. Previous maps like this have been made, but this image is at a resolution of 60 x 30 km (37 x 19 miles), so scientist can pick out individual cities which are a source of pollution. Antarctica Is Getting Ready to Really Heat Up Oct 7, 2004 - With all this talk of global warming, it may come as a surprise that Antarctica has actually been mostly getting colder over the last 30 years. But new research from NASA indicates that this trend is about to reverse, and the continent will warm over the next 50 years. Researchers found, ironically, that low ozone levels actually made the continent colder, but with restrictions on ozone-destroying chemicals around the planet, this cooling effect is going to go away as the ozone layer returns. If temperatures rise too high, the continent's ice sheets will melt and slide into the ocean, raising water levels around the world. Arriving This Week: The Ozone Hole Sep 1, 2004 - The European Space Agency's Envisat earth observation satellite is getting ready for the arrival of an annual event - the opening of the hole in the Earth's ozone layer. Since a hole first opened up in the mid-1980s, satellites have been tracking its arrival and shape for years, and scientists have gotten quite good at predicting the conditions that will create the gap. The ozone hole should open up in about a week's time, and then close up again in November or December when higher temperatures around the South Pole will mix ozone-rich air into the region. How Deforestation in Brazil is Affecting Local Climate Jun 9, 2004 - Satellites are giving scientists a bird's eye view of deforestation in the Brazilian rainforest, and the impact this is happening on the local environment. The researchers studied many years of data gathered by NASA's Tropical Rainfall Measuring Mission (TRMM), and found that the land heated up more quickly in the deforested areas. The increased temperatures let to more evaporation and greater rainfall during normally drier seasons. This challenges previous theories that said deforestation would lead to more arid conditions. May 3, 2004 - NASA satellites have helped scientists understand how pollution in Asia catches an express train ride on winds to travel all the way to the southern Atlantic Ocean; as much as half of pollution in the region could be from Asia. Scientists used data from two satellites and high-altitude balloons to spot the situations where near-surface smog from human pollution and natural forest fires "catches the train", and travels thousands of kilometres. Solar Plane Will Attempt to Go Around the Earth Mar 31, 2004 - The European Space Agency will be supplying technology to assist adventurer Bertrand Piccard's attempt to fly a solar-powered plane around the world. Piccard was part of the team that successfully flew a balloon around the Earth. The solar powered plane will have a 70-metre wingspan (larger than a Boeing 747), and carry enough batteries to be able to fly in the night as well. The plane would fly at an altitude of 10 km; well above the clouds to capture all the available sunlight. The first round-the-world attempt will be made some time after 2009. More Details on Water Vapour Feedback Mar 17, 2004 - New research funded by NASA indicates that some models of climate change might be overestimating what impact water vapour will have in raising average temperatures. This new study, based on data gathered by the Upper Atmosphere Research Satellite (UARS), verified that water vapour increases in the atmosphere as surface temperatures rise, but not as much as previously theorized. Water vapour is a significant greenhouse gas, so this new research will help scientists make much better predictions about future climate changes. The Origins of Oxygen on Earth Mar 17, 2004 - Oxygen is one of the most important elements on Earth to life, and it comprises a fifth of our atmosphere. It's a volatile element, so it can't exist in large quantities unless something, like life, is continually producing it. The mainstream view is that plants evolved oxygen photosynthesis early on, and then produced large amounts of oxygen. Another view, tested under laboratory conditions, is that when volcanic rocks weather, they release oxygen into the atmosphere. Perhaps it's a combination of these factors that built up our oxygen. Mission Sets Out to Map Southern Glaciers Mar 4, 2004 - An international team of scientists has set out on a three-week expedition to South America and Antarctica to survey glaciers to help determine the rate of climate change on Earth. They'll gather data using a specially configured DC-8 aircraft carrying a tool called the Airborne Synthetic Aperture Radar. It scans the ground in multiple wavelengths, polarizations, and in interferometric modes to "see" through treetops, sand and snow pack and produce topographic models. New Ozone Hole Isn't Quite the Record Sep 25, 2003 - The ozone hole above Antarctica is the second largest ever recorded this year, covering 28.2 million square kilometres - down slightly from the record in 2000. The observations were made by NASA's Earth Probe Total Ozone Mapping Spectrometer and the NOAA's Solar Backscatter Ultraviolet instrument, and were confirmed by balloon-carried instruments. Even through chlorofluorocarbons, which destroy the ozone in our atmosphere, were banned in 1995, they're still abundant and it'll probably take another 50 years before the ozone hole disappears completely. Print Version Print This Article |
|
| | Additional Information: WorldWideWeb | Privacy | Sale of Goods | Webmaster | Contact Info | Links | ||
| All Rights Reserved. Copyright Statement. Top of Page |
||