For years, Hollywood has celebrated Earth Day in order to raise awareness about environmental issues and to strike up a memorable dialogue about sustainable practices. And the film studios’ embrace of Earth Day has only strengthened over time. From PSAs to Paramount’s new micro-turbines, we take a look at the industry’s dedication to spotlighting one of the most important advocacy dates on the calendar. In 1990, the holiday got a pretty big boost from Hollywood when Time Warner called on some of their favorite talent to hammer home proactive things Americans could do to reduce their footprint on the planet. (Our favorites? A pony-tailed Kevin Costner teaching Meryl Streep how to recycle and Neil Patrick Harris as Doogie Howser giving a press conference about the health of his patient, "Mother Earth.") But in 2013, the film business's efforts have far exceeded PSA productions, and the good news is that a lot of progressive practices like electric car fueling stations, composting, a ban on plastic bags in commissaries, and required carbon emission reporting have become all but de rigueur on most major lots. As each of the main studios shoot to achieve "100% sustainable" status in the coming years, the pressure is on to determine creative ways to be the first to get there, and then some. In honor of Earth Day, we take a look at some of the ways Hollywood is committed to 'greening' up their practices:

Wicket, an eight year-old black lab-cross wearing a red vest emblazoned with the words "Search Dog", came to a sudden stop at the base of a thick willow tree, turning and sitting in one swift motion, and awaited her reward of a tennis ball for a successful detection. "Instead of using dogs to find narcotics, lets use them to find poop," Alice Whitelaw of Working Dogs for Conservation, said. Only one in 1,000 dogs have what it takes to become a detection dog. The Three Forks Mont.-based research group uses dogs to search for everything from invasive species to noxious weeds to rare animal scat to illegal snares used by poachers in Africa. Five Montana wildlife biologists came together in 2000 with a new idea to respond to a growing demand for non-invasive ways to do research.

Preserving the biodiversity of tropical forests could have the added benefit of cutting the spread of malaria, according to a new study. The finding contradicts the traditional view that clearing native forest for agriculture curbs malaria transmission in the Amazon rainforest.

The role of tree DNA tracking is increasing in the fight against illegal logging as evidenced by prosecution cases in USA and Germany. Modern DNA technology offers a unique opportunity: you could pinpoint the origin of your table at home and track down if the trees it was made from were illegally obtained. Each wooden piece of furniture comes with a hidden natural barcode that can tell its story from a sapling in a forest all the way to your living room.

Numerous epidemiologic studies have shown that a diet high in salt is associated with an increased risk of gastric cancer. Now Timothy L. Cover and colleagues of Vanderbilt University show that high dietary salt combined with infection by the ulcer-causing bacterium Helicobacter pylori greatly increases the risk of cancer. The study was published ahead of print in the journal Infection and Immunity. Stomach cancer, or gastric cancer, refers to cancer arising from any part of the stomach. Stomach cancer causes about 800,000 deaths worldwide per year. In the study, the researchers infected Mongolian gerbils with H. pylori. One set of gerbils received a regular diet; the other, a high salt diet. At the end of the experiment the researchers analyzed the animals' stomach tissues. Every animal on the high salt diet developed cancer, compared with just 58 percent of those on the regular diet. It appears development of gastric cancer required the presence of a particular bacterial oncoprotein, known as CagA, which is produced by H. pylori. Gastric cancer did not develop in animals on the high salt diet that were infected with a mutant H. pylori which did not produce CagA

Adding more color to your diet in the form of berries is encouraged by many nutrition experts. The protective effect of berries against inflammation has been documented in many studies. Diets supplemented with blueberries and strawberries have also been shown to improve behavior and cognitive functions in stressed young rats. To evaluate the protective effects of berries on brain function, specifically the ability of the brain to clear toxic accumulation, researchers from the Human Nutrition Research Center on Aging at Tufts University and University of Maryland Baltimore County recently fed rats a berry diet for 2 months and then looked at their brains after irradiation, a model for accelerated aging. All of the rats were fed berries 2 months prior to radiation and then divided into two groups- one was evaluated after 36 hours of radiation and the other after 30 days.

Anthropogenic US greenhouse gas emissions (GHG) amounted to a CO2-equivalent 6,702.3 million metric tons in 2011, down 1.6 percent from 2010 and 6.9 percent below 2005 levels. Longer term, US GHG emissions have increased at an annual average rate of 0.4 percent since 1990, according to the Environmental Protection Agency's (EPA) 18th annual US Greenhouse Gas Emissions and Sinks (Inventory) report, which was released April 15. A decrease in the carbon intensity of fuels used in electricity generation due to increased use of natural gas as opposed to coal, a "significant increase in hydropower" generation, and "relatively mild winter conditions, especially in the South Atlantic Region of the US" were the main factors underlying the drop in national GHG emissions in 2011, according to the EPA’s "The Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011."

My first reaction when I heard details of this week's deadly fertilizer explosion in Texas was horror. My second thought was, "Maybe I shouldn't have pushed to change that headline." National Geographic magazine just published in its May issue my article about how nitrogen fertilizer has shaped our planet. The article, with Peter Essick's beautiful pictures, describes fertilizer's critical role in providing our food, but also its toll on water, air and wildlife. When the article went up online, the headline read, at first, "The Curse of Fertilizer." I didn't like it. It seemed only half of the story. I complained, and the headline soon changed to "A Mixed Blessing" — just as news broke that the West Fertilizer Co. plant had caught fire and exploded, destroying much of the small town of West, Texas. The blast killed at least a dozen people — including emergency workers who were trying to fight the fire — and injured more than 100 others.

Earthquakes shake the land obviously. So do explosions and similar events. How about a hurricane? When superstorm Sandy turned and took aim at New York City and Long Island last October, ocean waves hitting each other and the shore rattled the seafloor and much of the United States – shaking detected by seismometers across the country, University of Utah researchers found.

Los Angeles is known not only for its celebrity clientele, but also for its congested roadways and heavy traffic, which consequently has led to severely polluted air, and the title of the "smoggiest city" in the United States. While air quality has improved somewhat in LA, a joint study by UCLA and the California Air Resources Board suggests that nearly a quarter of Angelenos are exposed to noxious plumes of freeway fumes almost every morning, far more people than previously thought.

Muslims have been asked to encourage their spiritual leaders, imams, to devote this Friday Khutbah or sermon (19th April 2013) to celebrate the blessings, graces and beauty of all of Allah’s creation. Muaz Nasir from Khaleafa who is leading the effort is also hoping to raise awareness amongst Muslim of the environmental challenges facing humanity. "The 'Green Khutbah Campaign' is aiming to challenge Muslims to become stewards of the environment by making changes to their daily routines," explains Nasir. "Although the evidence of environmental damage is stronger than ever, the public is starting to tune out due to the recent economic crisis and a lack of political leadership. But Muslims cannot tune out from the environmental damage – tuning out would mean that we are disregarding our moral responsibility to Allah's creation."

There are many benefits to community gardens. From greening urban ecosystems, to offering education and cultural opportunities, community gardens provide a venue for people to come together and stimulate social interaction. For individuals, these gardens also provide a venue for exercise, food production, and improved diets. These potential benefits have lead to a new study that reveals those who participate in community gardening have a significantly lower body mass index and have lower odds of being overweight or obese compared to their non-gardening neighbors.

Asteroids is a video arcade game. The object of the game is to shoot and destroy asteroids and saucers while not colliding with either. Real asteroids are minor planets (small Solar System bodies and dwarf planets) that are not comets, especially those of the inner Solar System. They have also been called planetoids, especially the larger ones. Shyam Bhaskaran of NASA is working a lot with asteroids these days. And also like many of his colleagues, the deep space navigator devotes a great deal of time to crafting, and contemplating, computer-generated 3-D models of these intriguing nomads of the solar system. But while many of his coworkers are calculating asteroids' past, present and future locations in the cosmos, zapping them with the world's most massive radar dishes, or considering how to rendezvous and perhaps even gently nudge an asteroid into lunar orbit, Bhaskaran thinks about how to collide with one.

A new report on the potential effects of climate change on NOAA's Olympic Coast National Marine Sanctuary uses existing observations and science-based expectations to identify how climate change could affect habitats, plants and animals within the sanctuary and adjacent coastal areas. It also outlines new management recommendations for the sanctuary, and sanctuary officials called it the first step toward addressing them. They also said the report issued by the sanctuary, Climate Change and the Olympic Coast National Marine Sanctuary: Interpreting Potential Futures, will provide a foundation of information and identify key issues facing the sanctuary.

While satellite data has shown aerosols — tiny polluting particles in the air — to be rising over India, a new study based on primary data gathered from measuring instruments installed in a network of stations confirms the trend. The study, by a team from the Vikram Sarabhai Space Centre, Thiruvananthapuram, and Indian Institute of Science (IISc), Bangalore, published online in Geophysical Research Letters last month (14 March), is based on the principle that aerosols absorb the sun's rays as they reach the earth's surface.

What would you say is the most littered item on US roadways? I think of two things: gum and cigarette butts. But let's focus on cigarettes for now. Cigarette filters are made from cellulose acetate, a plastic which is technically biodegradable. However, cigarette butts only degrade under conditions described by researchers as "severe biological circumstances," such as when filters end up in sewage. Even under optimal conditions, it can take at least 9 months for a butt to degrade.

While satellite data has shown aerosols — tiny polluting particles in the air — to be rising over India, a new study based on primary data gathered from measuring instruments installed in a network of stations confirms the trend. The study, by a team from the Vikram Sarabhai Space Centre, Thiruvananthapuram, and Indian Institute of Science (IISc), Bangalore, published online in Geophysical Research Letters last month (14 March), is based on the principle that aerosols absorb the sun's rays as they reach the earth's surface.

Lead is a nasty poison and can kill. So can bullets. Lead ammunition continues to take a deadly toll on endangered California condors that live in and around the Grand Canyon. Seven of the 80 wild condors in Arizona and Utah have died since December; three of those deaths have been definitively linked to lead poisoning from ingesting spent lead ammunition fragments in carrion and lead poisoning is suspected in the other four deaths. So bullets kill and, in this case, even by ingestion.

Applying a maxim from computer science to biology raises the intriguing possibility that life existed before Earth did and may have originated outside our solar system, scientists say. Moore's Law is the observation that computers increase exponentially in complexity, at a rate of about double the transistors per integrated circuit every very two years. If you apply Moore's Law to just the last few years' rate of computational complexity and work backward, you'll get back to the 1960s, when the first microchip was, indeed, invented. Now, two geneticists have applied Moore's Law to the rate at which life on Earth grows in complexity — and the results suggest organic life first came into existence long before Earth itself.

Permaculture is the branch of ecological design, which promotes development of sustainable and self-sufficient natural ecosystems. Focusing on twelve tenants, or design principles, that center on taking care of the earth while setting limits on consumption and redistributing surplus, the movement has yet to gain mainstream scientific acceptance. However, with help from a new album, "Permaculture – A Rhymer's Manual," Formidable Vegetable Sound System hopes to bring attention to permaculture and it's principles through their unique musical stylings. Globetrotting permaculture troubadour, Charlie Mgee has composed an entire album about sustainability, a topic most artists wouldn't think of touching without sounding too corny or too righteous. But who knew this new genre of edutainment (education and entertainment) would catch on? And who knew songs about permaculture could sound so cool and refreshing?