Question: Why is Venus hotter than Mercury, despite being further away from the Sun? 5th Grade Science Fair answer: Because Venus’ atmosphere has a greater concentration of greenhouse gases, such as carbon dioxide (CO2), which trap solar heat the same way a greenhouse does. Makes sense, right? Well, as a result of humans releasing excess greenhouse gases into the atmosphere since the start of the industrial revolution, the average temperature on Earth is now slowly increasing as well. The scientific evidence linking this rise in temperature to human activity is extremely strong; in 2007, the Intergovernmental Panel on Climate Change (IPCC) – comprised of 1,200 of the world’s best climate scientists – released a report which concluded that “most of the observed increase in globally averaged temperatures since the mid-twentieth century is very likely due to the observed increase in anthropogenic (man-made) greenhouse gas concentrations”. After poring over hundreds of peer-reviewed studies on climate change dating back to 1970, scientists at Columbia University’s Earth Institute concluded that “Anthropogenic climate change is having a significant impact on physical and biological systems globally”. A 2008 study by scientists at Lancaster University found no discernible link between solar rays and global temperatures (a popular argument of climate change “sceptics”), concluding in rather blunt terms that “the IPCC has got it right, so we had better carry on trying to cut carbon emissions.”

The Amazon rainforest is both the largest and most species-rich rainforest in the world; one-tenth of all known species, and one-fifth of the world’s birds, live there. Over a hundred indigenous nations have lived and thrived in the Amazon for thousands of years. A single squared kilometre of land in the area can contain over 90,000 tonnes of living plants. Beyond its rich biodiversity, the Amazon rainforest also performs a vital climatic function by storing millions of tons of greenhouse gases per year, thus helping to prevent climate change. Sound nice so far? Western civilization didn’t think so. Beginning in the 1960s, Brazilian migrants started running large-scale farming operations inside the Amazon rainforest itself, kicking off the widespread deforestation that has reached a fever pitch in recent decades. Interesting McFact: 91% of the Amazon land deforested since 1970 is now being used as livestock pasture.

Composed of the isotope Uranium-238 (a byproduct of the nuclear fission process that nuclear reactors and weapons rely on), depleted uranium is an extremely dense (and extremely radioactive) metal which has a wide variety of uses, from radiography to aeronautics. But depleted uranium – or DU for short – is most well-known for its military applications in the form of armour-piercing bullets and shells. While DU is known to be both radioactive and toxic, the extent to which exposure to the substance is a hazard to human and animal life is still hotly debated; while numerous studies have failed to draw a link between DU exposure and human cancers, correlations have been drawn between DU and birth defects among children of veterans of the 1991 Gulf War, in which DU munitions were widely used. A 2001 study of 15,000 American Gulf War veterans found that “the risk of birth defects in children of deployed male veterans… was about 2.2 times that of non-deployed veterans”. Tying these statistics directly to DU exposure, a 2005 report concluded that “the human epidemiological evidence is consistent with increased risk of birth defects in offspring of persons exposed to DU.” Thanks to its continued use by Western armies in Iraq and its 4.5 billion year half-life, depleted uranium will likely be harming life on Earth for eons to come.

The ozone layer is a layer of the Earth’s stratosphere which contains a relatively high concentration of the triatomic molecule ozone (O3). The ozone layer is responsible for absorbing approximately 95% of the sun’s high frequency ultraviolet light, thus sparing the Earth’s surface – and its many lifeforms – from being bombarded by electromagnetic radiation. In the late 1970s, when scientific evidence first began emerging that manmade halocarbons like chlorofluorocarbons (CFCs) were seriously depleting the ozone layer, many industrialized countries began restricting the use of CFCs, leading eventually to the 1987 Montreal Protocol which sought to formally phase out the production of compounds responsible for the alarming “holes” in the ozone layer. While many people believed that the ozone layer had been essentially saved as a result of this international agreement, as of 2003, scientists could only speculate that the depletion of the ozone layer “may be slowing down” thanks to the ban on CFCs. This slow progress is a result of the fact that many CFCs can survive in the atmosphere for up to 100 years, which means that it will be a long time yet before the ozone layer truly starts to recover from the damage caused by human pollution.

The term “soil contamination” refers to the presence of harmful substances – such as chemicals or heavy metals – in the soil, and is generally a result of human activity. Soil contamination can harm every aspect of a biosphere, from the plants which absorb the contaminants through their roots to the animals which fall ill after burrowing in or touching contaminated soil. Soil contamination is also a serious threat to humans, who can become sick or die by coming into contact with contaminated soil, ingesting vegetables grown in contaminated soil, or drinking water that has been contaminated by polluted soil. In China alone, there are 100,000 square kilometres of contaminated soil, and contaminated water is used to irrigate 32.5 million more square kilometres of cultivated land, which in turn causes 12 million tons of grain to become contaminated by heavy metals each year.

Far from being a potential source of superhero powers, radioactive waste is actually a very dangerous byproduct of the nuclear and oil industries’ operations. Radioactive waste is categorized according to the danger it presents, such as the “low level waste” (LLW) produced by industrial and medical sources and which is comprised of mostly clothing, tools, and other debris which is only slightly radioactive for a relatively short period of time. By contrast, “high level waste” (HLW) refers to the transuranium elements and fission products left over from the power-generating process of a nuclear reactor. HLW is extremely radioactive and must be completely sequestered from any biosphere, such as within the deep geological repository that has been proposed for Yucca Mountain, Nevada, USA. While sequestering nuclear waste is better than doing nothing, it doesn’t solve the long-term issue of what to do with nuclear waste. The United States, which produces a great deal of radioactive waste as a result of its nuclear power plants and other industries, currently suffers from (according to its own Department of Energy) “millions of gallons of radioactive waste, thousands of tons of spent nuclear fuel and material [and] huge quantities of contaminated soil and water”.

Genetically-Modified (GM) crops are plants that have had their DNA structure altered by human beings through the use of genetic engineering. By altering the plants’ genetic structures to, for example, be insect-resistant by containing an inborn insecticide, or more herbicide-tolerant (like Monsanto’s notorious “Roundup-Ready” GM soybeans), proponents argue that GM crops will allow farmers to produce larger yields. However, an April 2008 study by the British non-profit Soil Association found that “the yields of all major GM crop varieties in cultivation are lower than, or at best, equivalent to, yields from non-GM varieties.”[7] Another major problem with GM crops is that too little is yet known about them to fully appreciate their long-term effects on the health of the humans that eat them and on the overall biodiversity in the regions that they are grown. Already, GM crops have been found to have contaminated organic maize in regions of Mexico where no GM crops were growing,[8] disproving claims by the GM industry that their artificial plants can be effectively controlled. Ultimately, the GM crop question boils down to money; influential corporations like Monsanto and Nestlé reap billions of dollars a year from the sale of GM foods and synthetic pesticides which may well be doing irreversible harm to both our bodies and our environment.

The term “ocean acidification” refers to the changing acidity of the world’s oceans as a result of anthropogenic (human-caused) carbon dioxide (CO2) emissions. Over the past two-hundred years, as the industrial revolution spread and pollution levels skyrocketed, the oceans have absorbed approximately 40% of anthropogenic CO2 emissions.[14] Absorbing these abnormally large CO2 concentrations from the atmosphere has caused the chemical composition of the oceans to gradually change; between 1751 and 1994, the pH (a measure of acidity) level of the ocean surface has decreased from 8.179 to 8.104. This rise in acidity has reduced the amount of calcium available for use by calcifying organisms like corals, crustaceans and molluscs, who rely on it to grow their skeletons and cell coverings. By hampering the development of some of the ocean’s most humble denizens, ocean acidification threatens the entire marine food chain.

Colony Collapse Disorder, or CCD, is a mysterious phenomenon whereby worker bees suddenly disappear en masse, causing their entire colony to collapse. The bizarre crisis began in the United States in late 2006, where CCD-afflicted bee operations reported losing nearly double the usual number of bee colonies over the winter. This unusual disappearance of bee colonies doesn’t merely threaten the price of honey at the supermarket so much as the entire global food chain; the United States alone grows over 15 billion dollars worth of crops each year which are entirely dependent upon bees for pollination. If too many bees disappear, so will those crops, which could cause already-rising food prices to skyrocket out of the reach of many consumers. While CCD has been blamed on everything from cell phones to viruses, its cause remains ultimately unknown. While the world’s best entomologists and biologists work to better understand the phenomenon, we can only wonder if the worst of CCD is yet to come.

The Holocene Extinction Event is the bleak, inevitable end result of industrialism: everything is dying, and yes, it’s completely our fault. Thanks to centuries of raping the land, polluting the air, poisoning the water, clear cutting the forests, and massacring animals because their dead bodies taste better than vegetables, we have sent the global biosphere into a tailspin from which it will never recover. If you wept for the noble dodo, you’ll appreciate knowing that up to 140,000 different species are now going extinct every year – a rate 100 to 1000 times greater than the average extinction rates throughout Earth’s history. Nothing is going to slow down – much less stop – the precipitous collapse of life on Earth other than a full-blown reorganization of human societies the likes of which we can only barely conceive at this point. Whether you simply start riding your bike to work or become a full-fledged eco-hero, there’s no time like now to become a part of the solution.