Earth Day is a reminder that we only have one planet, so we should probably try to tidy it up a little on its special day.NASA

Climate change, wildlife conservation, deforestation, ozone depletion, air pollution, water pollution, land degradation -- the list of environmental challenges, the root cause of which is human interaction with the Earth, is long and daunting. Earth Day is a time when we all take notice of these problems, and try to do our part to clean up the mess we all are responsible for making.

Some ideas to help the planet are simple, sensible and easy to do, like walking instead of driving when possible, taking using bags to the store, or recycling.

There are other ways to aid the environment that are expensive, complicated and occasionally downright crazy. This special Earth Day slideshow is dedicated to the latter.

Could you tell this face to take a hike? At least one New Zealand economist thinks you should.Corbis Images

If you want to lose friends on the Internet, tell them you don't like cats. If you want angry mobs of cat enthusiasts cursing your name, call for a ban on cats.

New Zealand economist Gareth Morgan made such a bold proclamation earlier this year when observing that the introduction of the domestic cat has largely been responsible for the extinction or near extinction of many of the country's native bird population. In fact, domestic cats are primarily responsible for the extinction of nine species and have led to 33 native bird becoming endangered, according to AFP.

Morgan didn't call for the all-out removal of New Zealand's cat population, but implored owners to take a series of steps to minimize the effectiveness of their little killers pets, such as keeping the cat indoors or tying a bell around the animal's neck.

Tornados have the power to destroy towns. But with the idea of Canadian researchers, they might one day be able to power cities.Corbis Images

As much as fossil fuels damage the environment, no other energy sources can provide the amount of energy needed to power 21st century global demand as economically as coal, oil and natural gas.

The need for cleaner, cheaper alternative energy sources has led inventors and investors to pursue all sorts of solutions.

According to Forbes, a Canadian engineer with the backing of billionaire investor Peter Thiel is working on a plan to tap tornadoes as a source of carbon-free energy.

Called an atmospheric vortex engine (AVE), the idea is to create tornado-like vortexes to spin turbines that would generate electricity.

Power from cow paddies is already proving profitable for some farmers.Corbis Images

Green and clean are not always the same thing. As gross and frankly unexpected as it may seem, there's power in poop -- and urine.

Waste, from both animals and humans, in liquid and solid form has already been studied for a range of applications that would ultimately help the environment.

Converting solid waste from animals into methane has proven not only feasible but also potentially profitable. One farm in Pennsylvania, for example, with 600 cows that produced 18,000 gallons of manure daily saved $60,000 a year by using the methane to power the facility. Poo power is so promising that even Google is getting its hands dirty, investing $1.2 million in a farm in North Carolina that collects methane from hog waste.

With the help of bacteria, even urine can be converted into energy to power even the most fuel-thirsty vehicles. In 2011, scientists announced that so-called anammox germs can convert ammonium, found in urine, into hydrazine, a rocket fuel.

PHOTOS: 10 Bizarre Sources for Alternative Energy

Launching tree mines into a once-fallow field can be both Earth friendly and fun.U.S. Air Force

Given our much more impressive record of ruining the environment as opposed to our relatively paltry record of doing much to improve it, maybe embracing our destructive impulses could be a means of doing Mother Earth a solid.

Outdated military aircraft that were once used to drop landmines could be retrofitted to drop tree mines, according to TreeHugger's Brian Merchant.

Not only would these old planes that would have otherwise been left idle, abandoned to rust in an aircraft hangar, be recycled to have a purpose; by aerial bombing new forests with seeds, the planes could also plant some 900,000 trees per day.

Volcanoes have inspired one potentially far-out geoengineering scheme.Getty Images

If aerial bombing is one way to make a greener planet, could we also blast our way to a cooler planet?

During a major volcanic event, ash, gas and aerosol particles are blasted into the stratosphere and can spread over the planet over days and weeks. Some volcanic gasses, like carbon dioxide, can promote global warming. Others, however, like sulfur dioxide can lead to global cooling.

Although we can't induce volcanic eruptions (and certainly wouldn't want to try), scientists have been exploring the idea, through computer simulations, of releasing aerosols into the atmosphere that would have a similar effect to a major volcanic event that leads to global cooling.

Peridotites formations like these can absorb carbon dioxide from the atmosphere.Corbis Images

If global carbon input is only going to grow, carbon sequestration, the practice of capturing and storing excessive atmospheric carbon, may prove necessary as a means of mitigating the effects of climate change.

Given the scale and complexity of the problem posed by a warming world as a result of an increase in greenhouse gasses, you might be surprised at the simple and potentially effective resource we have at our disposal: rocks.

Rocks called peridotites have the capacity to absorb carbon dioxide from the atmosphere. As reported by Discovery News, Oman hosts a strip of peridotites 350 kilometers (217.5 miles) long and 30 kilometers (18.6 miles) wide.

If all that rock were exposed to atmospheric carbon, which researchers acknowledge is highly implausible, the rocks could store away 4,000 years of human carbon emissions.

Even covered in chocolate, there's no way we could have made this cricket look more appetizing.Corbis Images

Cows, pigs and chickens might all be staples on dinner tables across the country. But the energy needed to raise these animals and the waste they produce combined with the always increasing appetite for meat products makes meat production a significant source of pollution.

As a means of enticing consumers to change their dietary habits without having to go vegetarian, some adventurous and environmentally conscious eaters are advocating the idea of putting bugs on the menu.

Food made with meal worms or insects can not only be cheaper to produce than meat made from more familiar sources; it's also better for the environment. They require less land to raise, take less energy to maintain and produce less waste.

Bug-based food is also supposedly delicious; we just haven't gotten around to trying it yet.

Does this plan look easier than simply not wasting electricity?ESA/NASA

A global problem like climate change will require a global solution. If left unaddressed and reduced greenhouse emissions aren't part of the equation, even the ideas that seem lead grounded can rise above the rest.

A giant cloud of asteroid dust could act like a giant shade for the planet. The dust cloud would deflect sunlight and cool the Earth.

Putting this plan into action, however, could prove just as difficult as the problem it's meant to solve.