Sadly, there is more information floating about the "hoax" of global warming than there is about real sciences... 

Scientists are loosing the war. 
The denialistic propaganda against anthropomorphic warming is rife and uses weird and powerful ways to make sure most people have no idea about reality — or become totally ignorant about science in general. Go back and watch "Cocoon" to give you a warm feeling as you're getting old... Great... No, folks, life is not like this.
The internet is jam-packed with anti-global warming crazy stuff, some not very funny videos involving chickens and some seriously bad disinformation using bogus publications and totally erroneous fiction —all of which overtakes the seriousness of the global warming issue. 
Having done far too many things in my life, including the production of radio-active material and learning several languages, having studied in detail the processes of the earth including the destruction of our natural environments, having invested time to study the bio-genetics that drive life and having done much aesthetic investigation about philosophical thoughts, I hope I have reached a level of understanding and creativity quite above the moronic attitudes and crass lies coming from the denialists... I could be wrong, though, but I do not know so.
Meanwhile, these denialist crazies act like religious zealots at the time of the Spanish inquisition,  preaching god while robbing the Andes from its gold... or like the Italian popes chastising Galileo Galilei for telling Copernicus was right. The frightening reality here, in a twist of perversion, they claim to be the Galileo of scientific rigour, in an effort to confuse even more the issue.
Thus, I despair. We are being hammered. Those of us who understand how global warming works — and how ANY bloody thing works for that matter, including the atomic quarks, the muons (as I have mentioned before, the Theory of Relativity is far more complex than the Global Warming processes, but Einstein knew how to sell it... and he did not have a multitude of absolutist moronic denialists fighting the science at the time) and the rest of them weirdo particles — we are being buried by a rabid society of clever idiots.
I say clever because they know how to appeal to the lowest common grubby denominator, in which knowledge is relegated to a sputtering yarn in front of the 12th glass of beer at the pub. 
We need to fight.
I could go on step by step and explain the values of natural development and of the anthropomorphic processes that this earth is submitted to, till my brain hurts but the moronic virus has already penetrated the psyche of the idiots and that of the evangelicals even further.  
There should be NO debate on the science of global warming. 
Science can be wrong though. Yet, it's the privilege of scientists to admit being wrong when they are, while the rabid mobs would never admit ever being wrong because they never look at why or how they could be wrong, and because they deliberately use false premises to support their fake case from the start.   
For example there is a strange debate at the moment (I've no idea from): did the water on earth come from out of space? 
This to my mind is a grand idiotic debate... The question is skewed. For example it is well-researched and formulated by cosmologists that the sun from its infancy till its death in about 5 billion years time, is too small, thus is incapable of creating ingredients such as oxygen and carbon. As explained by respected cosmological scientists, most of the heavy ingredients in the solar system come from "outta space", mostly created within super novas, giant stars that explode from time to time. One of these would have exploded billions of years before the solar system was formed. Only these super heavy stars in their transformations can produce heavy elements under the weight of super-gravitational forces and super high temperatures. Our small sun can only deal with not much more than hydrogen and helium. That's all, folks. Thus oxygen was formed, like most of the elements we've catalogued on Earth, within the explosion of a Supernova Star and dispersed into the cosmic "void" eventually collected by new smaller star systems where the heavier elements would position themselves at specific levels from the centre of action — the new sun — see Laplace theories if you never heard of them. 
Thus, was water formed outside the earth and brought home by icy comets that would have been in much greater numbers than now? Possibly, but, as well, it is likely that in the heat of the moment, "spacial" hydrogen and "spacial" oxygen would have also combined locally to create water vapour above our planet, like a cloud about 20,000 kilometres thick until it cooled and fell into the "large cracks" of the planet's surface — the oceans plates... My theory for what it's worth...
The Earth is a small liquid planet. Call it luck, call it what you like — except "god" — the conditions on its surface became favourable for life to develop nearly 4 billion years ago. All the ingredients to generate animo-acids came from space, like the elements that made the earth also "came from space". That amino-acids formed on earth and could also be generated in space is not impossible either. The known elements are the only elements known in the entire universe (though we're trying hard to "understand" the dark matter yet). The conditions have changed since then and continue to change... The earth has gone through upheavals such as meteorite impacts and atmospheric changes, but there has been survival of life throughout these and, only for the last 450 million years, life has managed to "conquer the land". Evolution and devolution has been in flux with the changes and some evolution also created some of the atmospheric and surface changes. 
Presently, NOT accepting that humans have changed the surface of the Earth in the last say 4000/10,000 years — especially in the 150 years — would be being blind to the obvious. 
We have burned forest, we have modified the natural vegetation cover by replacing it with fields of wheat and other "selected" plants, we have develop urbanisation to a great scale, and our roads are a danger to most wild animals trying to be a chicken... I mean our roads have divided nature into "strips". We have favoured some animal species versus others,... No kidding, we have introduced pests like the cane toad killing "our" wildlife and triffids that are "choking" our waterways to death. We have bombed each others, we have exploded atomic devices in the Allen belts... WE HAVE MODIFIED THE SURFACE OF THE PLANET, including the sea in which we have added our crap into, from toxic material such as mercury to indestructible plastic and other unmentionable stuff...
WE ARE LUCKY that life in general is resilient, though in many specific cases, indigenous species under threat from various HUMAN-CREATED/INDUCED factors (loss of habitat, introduction of alien species such as rabbit, foxes, camels, buffaloes — the list is LONG) go over the cliff and become extinct. They die as a whole. We know about the Tassie devil's survival being very borderline now, while 40 years ago, this species was still "healthy". What has changed? Humans encroaching further and further on their "territory" and the use of some pesticides?...
Our usage of "pesticides" — and of other products such as "oestrogen" outside its natural environment — is nothing but scandalous.
As we cannot escape that we have modified the surface of this planet, so what about its atmosphere? HAVE WE MODIFIED the atmosphere? For the rabid denialists, it's either we have not ... or we have modified it, negligibly ... or some irate monkeys will argue we've improved it... —what's a couple of degrees Celsius extra between friends in 2100?
WE NEED TO DO SOME HARD SCIENCE TO FIGHT THIS CRAP.
Most of our scientific observations point to an unusual "recent" change in the behaviour of the atmosphere.
All scientists, pro and against anthropomorphic global warming, recognise that the Earth's atmosphere is warming. At this stage there are many scientific mathematical models computing that by 2100, the present trend will take us to a temperature increase of between 4 and 6 degrees Celsius. Some computer models even calculate up to 9 degrees increase and this is not science fiction. It has all to do with "statistical" input and minimising error of bracketing. But the World scientific consensus is that we need to limit the damage at or below 2 degrees Celsius EXTRA, to avoid massive upheavals, and this presently demands a mighty sacrifice...We have to give up the carbon god, substantially.
As well, a noticeable change in the "fury" of nature is being observed (and predicted quite below this observation for conservative calculation)... By this I mean 'catastrophic" climatic events are getting more powerful and more frequent — from drought to floods and storms... and this with only but less than a degree Celsius extra since the 1850s... So what's coming next? Who cares?
A few years after I arrived in Australia, Lake Eyre flooded to a record level for the first time in a century... though the Lake had flooded a bit before in the 1950s and other years, if my memory is correct, the lake has flooded near record times since, with what appears to be an "accelerated" momentum. This year and last year, the lake has seen flood water (apart from its "annual" rainfall of 125 mm — against a 4.5 metres of yearly evaporation) come onto its shores.
Scientific observation of temperature all over the world, has show the planet's atmosphere is warming...
Other observations are telling us the ice at the poles is thinning — except in a few places such as the centre of Antarctica which is getting wetter (Antarctica being the driest continent on earth, but it has little or no evaporation). 
We know the glaciers in most part of the world have retreated by massive amounts in the last 50 years. only a few in specific places are gaining ice, including as mentioned the centre of Antarctica.
The combination of all these indices and more (including the sea level rising —undeniably calculated) tells us something. Meanwhile, we cannot feel the change of temperature because the increments are "minute", and we are used to daily changes of far greater magnitudes that are part of the normal 24 hours and yearly cycles...  thus the climate change is only measurable with instruments.  I repeat here: All scientists, pro and against anthropomorphic global warming, recognise that the Earth's atmosphere is warming. 
Thermometers, hygrometers, clocks and barometers were invented a reasonably long time ago with quite high precision then for us to accept the accuracy of observations made with these instruments. There is a clock in the Observatory, Sydney's Observatory Hill, devised in the 1820s that has an accuracy we still dream of on our computerised gizmos (see picture next comment). 
Using all these equipment and newfangled more precise gizmos we can now assert the speed of change and the momentum of change, contrary to the denialists who have but their big loud mouth as an instrument to probe the density of the air they pollute.

Accuracy and multiplicity of measurement are the keys to give us the proper statistical input. And the PRECISE picture is not rosy. But of course there are complications. As the sea surface warms up, there is more evaporation (as observed) but this evaporation in return can cool the surface by a smidgin. As well, the evaporated water can carry further latitudinally because of warmer climes (as observed).
As well, we need to account for earth wobbles, volcanic activity, solar flares, sidereal events, including meteorites, and the age of Tony Abbott, an aberration in itself — all of which can have an impact on the observations. These are included as interferences in the calculation estimates (still with an astonishing degree of precision, apart from Tony Abbott who has no clue about any of this, between his ears). 
More complication comes from the ice. When the ice is melting it absorbs energy (temperature) thus cooling somewhere else may happen tem-po-ra-ri-ly. I have already explained how an old fashioned refrigerator can produce more ice, while warming itself up and cooling the kitchen as the refrigerator door is left ajar. The sum-total of temperature is going up though, as more energy (heat-generated electricity) is needed to keep the refrigerator running. All we have to do is measure all the parts of the whole: the kitchen, the electricity supply, the refrigerator and the temperature of the ice (warming up) despite showing more ice caking up and water flooding the floor of the kitchen.

It's not as simple as it seems on the scale of a planet but SCIENTISTS ARE DOING IT with remarkable precision. More measurements need to be done but the end result is that THE EARTH'S ATMOSPHERE, in its lower layer, is warming — fast, in geological time scale — and warming the surface in the process.
So WHAT IS warming the planet's atmosphere? Well for starters we know with precision that some gases are "greenhousey while others are "less greenhousey" ... Without water vapour, methane, CO2 and others, the earth atmosphere would be about 30 degrees Celsius lower than it is. That's the science. Sydney's temperature would be about minus 5 in summer on average... This is the scale of what we're immersed in. Proper science can give us an accurate statistical study on this, despite contrariness from the denialists. 
When Lord Monckton is madly harping on about a cooling event 700 million years ago with far more CO2 in the atmosphere than now "apparently", I can argue that, then, all the atmosphere needed was a greater proportion of oxygen in it, to lower the temperature despite the higher concentration of CO2. Warming and cooling is all about the mix. 
Presently the mix is changing. HUMANS ARE CHANGING THE MIX OF GASES in the atmosphere. Denying this is like denying that the earth is a globe. Or denying that the sun provides lights to the earth. Or denying that our cell-phones use electromagnetic waves to let us speak to other morons.
This is the level at which we unfortunately have to fight... 
By our usage of Fossil fuels, we are adding EXTRA CO2 to the natural CO2 cycle in the atmosphere/biosphere/surface. We are adding EXTRA METHANE  in the atmosphere. Exacting experiments show us that CO2 and methane are "greenhousey" gases... Suggesting these gases would have no impact on the temperature of the atmosphere is like denying we've got two major ends in our digestive tract...
Actually, the denialists probably eat and shit from the same orifice... But this would be another story, and I retract this statement...
Meanwhile, the science of global warming is correct within its brackets of prediction. Not doing anything about global warming — i.e. NOT DOING ANYTHING ABOUT OUR EMISSIONS OF CO2 AND METHANE — would be like shitting in our own bed and rolling in it for pleasure. This is far more serious than a couple of nitwits presently playing with themselves in parliament. 
We have no choice but to support a politically inspired carbon tax though it's not ideally constructed yet, but it is the only tool we have in this country to reduce our emissions of CO2 and methane. Tony Abbott has no clue about anything relating to global warming. Most of his energy is spent in yapping mad in front of old farts waving placards against the carbon tax. We should expect better but no...
Thus we have to support the red-maiden, allied with the greens, even reluctantly, in her fight against the red budgie-smuggered idiot and his band of loonies... Mind you the Greens shot themselves in the foot when they demanded more from the ETS that had been agreed in principle by Malcolm and Kevin... but then this agreement was reneged on by Tony who pushed Malcolm aside... We needed the greens to go with the ETS... I have been alive too long. I knew the Greens' refusal was crazy: one has to get the foot in the door first, before flogging the Encyclopaedia Britannica or selling the new Hoover.
I can make a joke about it, but the lives of millions (possibly billions by 2100) of people are at stake. 
Not a laughing matter.