How much do you think about human trafficking? If you’re living in a First World country, probably not much. The red light district in Amsterdam. Many of the prostitutes are trafficked from Central and Eastern European countries. (Photo credit: Wikimedia Commons) Human trafficking doesn’t often touch our lives living in the suburbs—but for people in Third World countries and other parts of the world where it is more difficult to regulate human trafficking (or where authorities choose to turn a blind eye to infractions), it can be devastating.

Air pollution is a major problem in today’s world. Many of us spend every day of our lives breathing in smog without even thinking of the damage it is doing not only to our lungs, but also to the planet. Air pollutants contribute to the rise of global warming, a long-term change in the climate of the planet which will ultimately be harmful, maybe even detrimental, to life on earth.

What is deforestation? Unless you’re an ecologist, you probably don’t spend a lot of time worrying about the fate of the world’s forests, but you probably also don’t realize just how fast the forests on Earth are disappearing. Satellite images of deforestation in Eastern Bolivia (Photo credit: NASA) The rate at which trees are being felled for agriculture, manufacturing, and other reasons is quite astounding. The effects of deforestation are massive, adversely impacting biodiversity, the climate, and human life.

**At the end of World War II, American planes dropped two atomic bombs on the Japanese cities of Hiroshima and Nagasaki, killing and maiming hundreds of thousands. Six years later, four light bulbs in Idaho lit up. Their illumination was fueled by an experimental “breeder” reactor based on the infamous wartime technology used in Japan. As the world’s first generation of electricity from nuclear power, it was the beginning of an era that still persists.

Solar panels are quickly becoming one of the most popular clean-energy options on the market. A study conducted by Forbes proved solar power is the 10th fastest-growing industry in the United States. Nellis Solar Power Plant in Nevada, USA. This 140 acre installation provides 14MW of power to the nearby air force base. (Photo credit: Wikipedia) Never has there been more interest in clean energy than in the last decade. With the help of new tax benefits, businesses and families are learning the lucrative side of going green.

When we use solar panels to capture the sun’s radiation, we are going out of our way to do something the earth already does everywhere around us: capture and store solar energy. In fact, about half the solar radiation that hits our planet ends up in the ground. In this sense, geothermal energy represents a secondary source of sun power. The Earth’s underground layers also harbor the heat of the distant past, beaming out from the flaming core of the planet.

It’s been called a “limitless” source of energy by advocates, and “volcano fracking” by critics - but exactly what is geothermal energy? From the Core of the Planet Diagram illustrating power generation from a hot-water hydrothermal system (Photo credit: US federal government) The term actually defines itself: “geo” refers to earth, and “thermal” means heat. A geothermal power plant extracts heat from deep within the earth. The intense heat from hot magma rises, which boils pools of water buried in crust rock.

3,850 zettajoules, a figure with 22 zeroes in it–that’s how much solar radiation our planet receives from our sun in a year. To get a sense of how much potential energy that number represents, consider that in just one hour, the shining of the sun unleashes enough power to supply the sum of humanity’s global energy needs for an entire year. And with our current level of solar technology, we would only need about 0.

While many people love snakes and even keep them as pets, others are flat-out terrified of them. Fear of snakes is so ubiquitous that snakes are traditionally used to symbolize evil in mythology, literature, and film. Of course, snakes are not evil, and many of them are quite docile, even friendly. But a number of species can be quite dangerous if you cross them in nature, especially if they feel threatened.

Numbers may not be everything, but being able to overwhelm an enemy with sheer size does lend a certain advantage. There are a lot of other factors to consider when you’re trying to determine the strongest military on the planet (like firepower, technology, training and more), but if you’re curious about the largest armies in the world in terms of active personnel, read ahead. Keep in mind that these figures are combined totals, incorporating not only army personnel, but also navy, air force, special operations, marines, and other branches.