On September 11, 2001, our world changed forever.

And not just because of the obvious. For three days after the attack on the World Trade Center, all commercial aviation came to a standstill in the United States. For the first time since 1914, when Tony Jannus piloted a wooden, open-air Benoist XIV biplane in the first commercial passenger-carrying airline flight from St. Petersburg to Tampa, Florida, traffic in the friendly skies above the amber waves of grain came to a screeching halt. And in those three crucial days, our entire understanding of global warming underwent a fundamental transformation.

But this literally earth-shattering revelation has not been getting a lot of press since that horrible day. Public interest in climate change is dwindling into either resigned apathy, or growing skepticism about the risks of global warming; a 14 percent decline in people who believe the earth is becoming warmer. At the current conference in Copenhagen, the emphasis has shifted away from what the hell are we going to do to save the planet before it’s too late to world leaders bickering and squabbling in an unseemly power struggle over who gets to pollute the most. And while the talks are failing as politicians shuffle carbon credits around like magicians with a deck of cards, global warming deniers are busily promulgating ever more heated and bizarre conspiracy theories.

Climate change is a hoax, they’re shouting from their soap boxes. Agenda 21 is just a smoke screen designed to enslave the Third World, and global warming is fraud, a steekin’ fraud, I tells ya, run by the Illuminati and the Rothschild dynasty and aliens from Alpha Centuri in a vast conspiracy with Big Business and Pharma and corrupt politicians to control the world’s resources in a scam for world domination! Global warming is a natural phenomenon, they’re insisting, 30,000 scientists have iron-clad proof (and leaked emails) that it’s all been propaganda designed to frighten us. CO2 is caused by tectonic plate shift, or the earth’s axis tilting, or sun spots, or Urban Heat Island effects, or water vapor, or cows farting. (Actually, the last one does have some validity; livestock ‘byproducts’ account for 32.6 billion tons of CO2 per year, or 51% of annual global GHG emissions.) It’s a natural cycle – we went through a Little Ice Age in the Holocene then global warming in the Middle Ages (actually, we didn’t), and volcanoes spew out more CO2 than humans do (again, uh-uh, human activity releases more than 130 times more CO2 than all our current active volcanoes combined). Anyway, modeling the environment is too vast, too vague, too complicated, not even scientists can agree with one another; we just aren’t capable of adequately simulating the atmosphere or understanding climate change.

Besides, why should we care how much we pollute the planet, since India and China don’t give a damn…?

So… a bit of Climate Change for Idiots to aid those of us who feel like we’re beating heads against the wall arguing with friends and relatives frantically denying The End is Nigh, all while driving their SUVs through the nearest McDonald’s drive-in, those poor benighted souls too obtuse to realize the causes of global warming are myriad, and that while – yes, they are correct, Big Biz and First World greed are busily maneuvering and dodging and scheming over who gets to profit the most from climate change – that doesn’t mean it’s not real. We’re too focused on the looters to realize that the city is burning down around us.

Climate change is complicated, but not impossible to understand. Anyone with a driver’s license for that SUV isn’t required to know that d = V /(2g(f + G)) ; drivers instinctively know enough physics to apply the brakes long before the car needs to stop. The reaction time for a driver to start applying the brakes is 1.5 seconds. In terms of climate change, we’re in that reaction phase – and we’d better start thinking about stomping on the brakes pretty damned soon. A driver who doesn’t care about braking before they crash is either stupid, suicidal, or crazy.

Let’s break this down into more easily digested morsels so that even those suffering from the current deficit of basic science in American school systems that their grasp of geological history is closer to The Flintstones than Charles Darwin can get a grip.

Dick and Jane are in a jet, flying over Kansas. Look, Jane, look! The jet is leaving a contrail behind us. See the contrail form cirrus clouds. Contrails last up to eight hours, says Jane, and only half a dozen of them are needed to grow and form a cloud the size of the entire state of Massachusetts. That’s really big, says Dick. Woof, says Spot, shivering down in the baggage hold.

Now for some basic math, something else that seems to be lacking in our classrooms these days:

Five thousand planes, give or take a few, are in flight over the United States at any given moment. In a single day, more than 87,000 are leaving contrails all over those friendly skies. On average, 64 million jet planes take off and land somewhere in the States, leaving behind contrails. Divide six cirrus clouds the size of Massachusetts into 64 million contrails, and that’s a lot of clouds. All this cloud cover is bouncing the sun’s energy back into space, keeping our planet cool in what’s been called ‘global dimming,’ which should be a good thing, right?

Um, not really. Now we need some chemistry… yeah, yeah, I know. They don’t teach much of that in schools anymore, either. But let’s give it a shot, anyway.

What exactly are contrails? Contrails and clouds are similar, made up of condensed water vapour freezing around small particles. Clouds form from ice crystals and other natural particles, like dust blown into the atmosphere by wind. Ice crystals melt into water, while dust, being generally inert, falls back to earth where it came from. Contrails, on the other hand, form around aircraft exhaust, including carbon dioxide, nitrogen oxides, carbon monoxides, and hydrocarbons such as methane, sulfates, soot and metal particles. The clouds formed by these exhaust particulates has another difference to ordinary clouds; ice crystals and natural dust is larger than hydrocarbon particulates, which form much smaller water droplets. Smaller water droplets reflect back more sunlight, but don’t grow heavy enough to precipitate as rain. Pollution-derived clouds actually decrease rain, adding to drought conditions.

Now add this in to what is known as the Asian Brown Cloud, a thick layer of smog covering a huge area of southern Asia and the Indian Ocean formed by combustion pollution, wood fires, garbage fires, burning fossil fuels in cars, industrial factory emissions, the usual culprits. In the monsoon months, rain washes this massive toxic cloud out of the air – and into the soil. But while this lethal crap is floating around in the atmosphere and causing droughts, floods, and killing two million people a year, it also is contributing to ‘global dimming’, masking its own impact on atmospheric warming. And before anyone gets too smug that the so-called ‘Asian’ Brown Cloud is all India and China’s fault and therefore their problem, it’s not unique to Asia; hotspots popping up in Europe, South Africa, South America, and North America – in other words, everywhere.

In September of 2001, we got our first real glimpse of what happens if we aren’t pumping vast quantities of particulate crap into the air alongside all the carbon dioxide waste. Current climate change forecasts only take into consideration CO2 emissions, which predict a maximum warming of 5 degrees by the end of the century, plenty of time to ‘do something’, everyone can relax, sit back, wait for scientists and politicians to come up with the answers all in the nick of time, don’t worry, be happy.

But climate change forecasts haven’t been factoring in global dimming. We don’t have a hundred years to come up with a solution – we’ve got about twenty to apply those brakes before it’s too late. Cooling particle pollution is already dropping off while the CO2 warming pollution is continuing to rise, which means a doubled accelerated warming - reducing cooling and increased heating at the same time. With the dual effect of global warming/global dimming, temperatures could rise twice as fast as previously thought, global warming exceeding two degrees by around 2030, at which point the Greenland ice sheet would melt, causing irreversible damage.

Once the Greenland ice cap begins to melt, nothing will stop it. After Greenland, the world's tropical rain forests will start to die off in the heat. By 2040, with only a four degree rise in global temperature, the Amazon Basin rain forest becomes unsustainable, subjected to devastating fires (think - Australia right now), all of South America turns into one vast savannah and ultimately desert.

As rain forests die and burn, those fires will release even more CO2 into the atmosphere, driving global warming still further and faster. In just a century, rather than five degrees hotter, the world could easily be twice that, which would be a warming more rapid than any other at any time ever in Earth’s history. Bar none.

Most European and northern plant species will not survive in a North African climate. But while a ten degree warming in Europe in a hundred years is merely catastrophic, a ten degree warming in an already hot country makes it completely uninhabitable. Life on earth begins to starve and die, which includes us.

And now for the coup de grace at the end of this chain of effect: a ten degree warming will lead to the release of a vast natural store of greenhouse gas bigger than all the oil and coal reserves of the planet. Methane hydrates store ten thousand billion tons of methane, a greenhouse gas eight times stronger than carbon dioxide, at the bottom of the ocean in a kind of frozen form, known to be destabilized by warming. Once these gasses start to be released, no matter what was done at that point to curb emissions, it would be too late. Ten thousand billion tons of methane, which would have twenty-five times the impact on temperature than a carbon dioxide emission of the same mass over the following 100 years, would be released into the atmosphere, the Earth's climate heading towards temperatures unseen in four billion years, with no way to stop it. All life on earth would become extinct. It’s the end of the world. And we're only talking two hundred years, tops.

But, yeah, those deniers are completely correct about one thing - the earth has been here before. Back when the only life capable of surviving in such an atmosphere and climate was precursors of bacteria. Totally natural, ya betcha. If we're really lucky, the earth will recover on its own, just like it did the first time around... in another four billion years.

Welcome to Venus, folks...