The answer is nitrogen fertiliser.

The gas is not CO2 but nitrous oxide and other nitrates.

Molecule for molecule nitrous oxide (N2O) is a far more potent greenhouse gas than carbon dioxide. N2O emissions from nitrate fertiliser contribute more to global warming than all the world's fossil fuel burning cars, trucks, trains and planes put together.

FIX THIS IN YOUR MINDS.

Do away with all the world's fossil fuel burning vehicles; ground all the passenger planes and within a few years we'd be back where we started because of the growing volume of N2O and other nitrate emissions. We have to tackle the nitrogen problem.

It is even arguable that nitrates are bigger problem than CO2 and we should be focusing on that first.* There are other health effects from nitrate pollution.

But let's focus on the global warming aspect for now.

A possible fix is genetically modified crops that require less nitrate fertiliser.**

So here's the question to greenies.

What about GM crops that requires less nitrate fertiliser and are more drought resistant to boot. (Less need for dams, less dry land salination)?

Would greenies accepted GM crops that genuinely helped the environment?

My guess is no. In fact you'd never get them to admit that GM crops could benefit the environment.

But let's hear from you.

*See: Something nasty in the air, New Scientist, 21 January 2006; and

**Could new GM crops please the greens?, New Scientist, 05 January 2008

Hmmm…another reason why population( & the need to cater to it) is a key issue in global warming.

So…
Where is this issue examined in “An Inconvenient Truth”?
When was it discussed at the recent Bali conference ?
How does it rank on our recently elected, climate savvy, govt’s agenda ?

over population is so inconvenient, that it doesn't exist. indeed, i find it hard to read the first two words, they're all blurry,fading, what did i write..

I though it was methane from cows?

Less artificial nitrates is obviously a good thing. No artificial nitrates is far better, and completely feasible. GM is certainly not the only answer. Actually i dont think its neccessary - what about the billions of dollars and emissions spent on wasting our greatest natural source of nitrogen - our own waste? Surely we can find acceptable ways to use this resource.

What about addressing the waste of nitrogen caused by artificial fertilisers and monoculture farming? NPK fertilisers leach into water far more readily than organic fertilisers, due to a reduction in soil microbiology and organic matter.

I am not completely against GM technology, i just think its unneccessary and question the motives of the people and companies developing and pushing it. How much GM research is being conducted by independent public funding? It also furthers the mentality of helplessness our society has, that someone else always knows better than yourself and if you just do as they say its all good. What i am convinced of is that as the oil runs out broadscale monoculture farming (GM's only application) will crumble and the cities will be in chaos. We should be growing more of our own food, not continuing to flog a dying horse.

Are these articles available online? New scientist does have a tendency to exaggerate things or leave them open to misinterpretation. I'd like to read what the articles actually say.

You folk are so right - the real issue is the population explosion but the politicians won't tackle it because it is political dynamite and the environmental movement won't get on board because there is no money to be made out of it.

Wind farms are much more profitable, but of little or not benefit to the tackling global warming. Even if we cut our emissions by 75% in Australia they population growth in the rest of the world would (partuicularly in India and Africa)wil negate any gains made.

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On a narrow technical sense the largest source of greenhouse gas is water vapor from the ocean , Yes I know it doesn't help :-)

I go with the majority for identifying the largest source of green house gases as city dwellers of the advanced economies ,
the poors do destroy the place but tend to do it on a low energy level ,
The very concept of a developed economy imply the use and abuse of fossil energy at an obscene level ,

it is impossible to be serious about climate change and remain silent on Australia being the biggest coal exporter in the world , unless your name is peter Garrett !

So the choice is clear ,be sincere and reduce the export or keep mum enjoy the lifestyle and the cricket

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Randwick,
It would have been more accurate to have said:
“I go with the [SPIN DOCTORS] for identifying the largest source of green house gases as city dwellers of the advanced economies “

Actually, China Is now by a number of accounts, the biggest producer of green house gasses –there is no getting around it, no matter whatever way you might try to fudge the figures/measures– (& India is quickly catching up)

“It is impossible to be serious about climate change and”:
-“remain silent” on population growth, or
-“remain silent” on the developING worlds need to make greenhouse gas cuts .

But then, who every r-e-a-l-l-y thought the climate change crusaders were “serious” about climate change ?