The Greens say they can offer a radical alternative for voters who are fed up with the three main political parties.
Mr Taylor says the Greens would introduce progressive tax reforms
They put climate change at the heart of their manifesto, saying it was a bigger threat than terrorism.
The Greens are fielding candidates in 200 seats - 25% more than the last general election - and say they have five key targets.
Labour, the Conservatives and Lib Dems all say they are determined to tackle climate change.
But the Green's main speaker, Keith Taylor, said their "privatise and pollute" agendas had led to soaring CO2 emission levels.
He claimed flooding in Boscastle and Carlisle showed the effects of climate change.
Replace VAT with eco tax
Invest in renewable energy
Tax on aviation fuel
Cut CO2 emissions by 20% by 2010
Recycle 60% domestic waste by 2010
Higher tax on incomes over £50,000
Oppose PFI schemes
Ban GM foods
Produce 30% food organically by 2012
Replace council tax and uniform business tax with land value tax
"Climate change is happening and it's happening now. The only people denying it are those who make their money from burning fossil fuels," Mr Taylor said at the manifesto launch on Tuesday.
The party also pledged to fund public services and green policies with money saved by scrapping Labour's road building plan, Britain's nuclear arsenal and ID cards.
The Greens want to replace VAT with a new eco-tax and increase NHS investment to £90bn a year by 2008.
They would spend the £30bn saved from the roads scheme on public transport and use money from eco-taxes to invest in renewable energy and to create more skilled manufacturing jobs.
And they would use £3bn from scrapping Labour's ID cards plans to invest in community policing.
Mr Taylor said they would not take power on 5 May, but denied voting Green was a wasted vote because, he said, the main parties would not address environmental issues.
"A real wasted vote is a vote for something you don't believe in," he said.
The party says it is confident of getting its first MP at Westminster.
It is focusing on seats where it did well in the European and London Assembly elections. Its top targets are: Brighton Pavilion, Lewisham Deptford, Norwich South, Leeds West and Holborn St Pancras.
The party would also work for arms reduction and cancel the debt to Britain of the 52 poorest countries.
The main parties strongly dispute the Greens' claim that they have neglected environmental issues.
Tony Blair has made tackling climate change a focus of his presidency of the G8 and Labour also point to their tax incentives for fuel efficient cars and efforts to increase household recycling.
The Conservatives say they would offer better leadership internationally over the Kyoto targets, including persuading the US to sign up. They also promise to protect the UK's green belt land from building.
The Lib Dems say all their policies have been tested for their "green" credentials, with new targets on renewable energy and waste recycling.
I agree with most of the party's policies, and think it's great that there is a party seriously trying to tackle environmental issues. However, from what I've read here, I see nothing about improving the NHS, education, etc. While the environment is certainly important, so are these issues.
Its a vote grabber for sure BUT until the US gets in on global green issues its a drop in the ocean sad to say.
Christopher Hannant, Bournemouth, UK
Yet more proof that you can promise anything you like when you have no chance of getting elected. I expect more of the same from the Lib Dems.
David, Solihull, West Midlands
A Green government would either save Britain or destroy her economy. This, however, is not what is being proposed. A dedicated Green MP would be a powerful voice in the House of Commons, preventing the major parties from skirting the issue while still allowing them to deal with non-environmental issues. For those reasons, I urge those in constituencies targeted by the Greens to vote for the protection of the planet.
Ronald Collinson, Whixall, UK
This is why Labour doesn't want to introduce Proportional Representation - because it can't stand the idea that large numbers would vote for policies espoused by the Greens. For many, the Greens do not go far enough, but by depriving them from having a voice in Parliament they help perpetuate the notion that the political system and political parties per se are inherently corrupt and narrow in scope.
Linden, Brighton, England.
Simple fact is, if we don't sort out climate change there won't be any more debates or terrorism threats, because we'll all be gone. The environment is the most important issue to deal with.
Great positive stuff, I only hope there is a Green candidate I can vote for.
Joanne Hall, Thurrock
Keep at it, you will get people to realise how foolish they art being. It may take some time, but I hope not.
Neil A.S.Armstrong, Leamington Spa, UK
Best of luck to the Greens. You're not standing in my seat, and I'm not sure if I'll ever vote for anyone except Labour. However, many of your ideas are radical, original and worth hearing. It's vitally important that these ideas are heard, and I hope that you will secure parliamentary representation following your successes at European and local level.
James, Cardiff, UK
It is time to address environmental issues and raise social awareness of the deteriorating environment around us. The Green Party are the only political party that seem to demonstrate a clear intent to improve the current state of the environment. As outlined in the manifesto, climate change is a critical subject that needs to be improved to certify a healthier living environment for the next generations. Although many people believe that voting for the Greens would be a wasted vote, the need to make a change has never been this necessary! The NHS certainly needs the £90bn and the appalling state of the public sector undoubtedly requires a full revamp as well as a major alteration to community policy. I fully support the Green's unlike the hypocritical, arrogant and ignorant remaining parties.
Richard Boardman, Birmingham, England
I would love to vote Green, if only they had a candidate here.
Nick, Hastings, E Sussex
I wish I could transfer my vote to another area to help a green party candidate get elected. The other parties are all out for the selfish vote.
Malcolm, Wirral, UK
I used to vote Conservative but the Greens are the only party talking about the mess we've got the planet into. If they're standing where I live, I'll vote for them.
Jonathan, Shropshire, UK
I thoroughly agree with the Greens' policies. For many it is seen as a weakness to care about our society and our environment but the Greens are a breath of fresh air. Go Greens, infiltrate the 'neo-liberal, capitalist menage ą trois' in Westminster and give us some MPs to be proud of. Tragically my seat is Swindon North and so I have no Green Candidate.
Neil Gutteridge, Swindon
Anything has to be better than the current crop of politicians who have constantly failed to deliver on environmental matters. My advice to the Green Party is simple. Keep going! We'll get there in the end.
Graham Gilbert, Fordingbridge, England
Quite clearly the claims of the 'big three' in this article are false. There were continual rounds of house-building around my childhood home in the 80s and 90s, all carefully situated away from public transport; road and air traffic have both increased massively in the last eight years and we are in danger of missing our Kyoto targets. In this situation, all the Greens should have to do is alert voters to their existence and let the truth do their campaigning for them!
Peter Barber, Glasgow, Scotland
Support for the Greens has been growing steadily over the past few years, but they really need to make their presence felt, and their standpoint on various issues known. They should push the fact that they intend to do something serious about our public transport, which compared to that of most European countries is an embarrassment. Housing will also be an issue - affordable housing is one thing, but seeing the large, detached, hardly energy-efficient, ugly box-like houses being thrown up everywhere, with every concession for the car owner made and no thought given to public transport links for the thousands of new inhabitants. I think the Greens should make it clear how their policy in this area differs from the other main parties. Keep up the good work - I'll be voting for you!
Pascale, Cambridge, UK
I love the ideas but like many I think I worry about these things in practice. Just take a war on roads and road users for instance. You only have a spend a little time on the motorway to realise that our society runs on road-borne goods (supermarket lorries, transport firms, parcel firms etc). It can and should change but just trying to make it harder (and more expensive) for everyone involved doesn't help.
Rich, Lancaster UK
I agree with most of the Greens' policies. I hope I have the courage to vote with my heart and not my head.
Jason, London, UK
The "Big Three" say nothing to me about my life. I have no trust in any of them. The Green Party represents most closely the views I hold. Sadly I don't believe there will be a Green candidate in my constituency (Leeds Central) so I can't vote for them.
AndyP, Leeds, UK
Don't forget the single biggest threat to our planet - population growth! Without immediate control, the battle for nature will almost invariably be lost.
Henrik, Colby, Isle of Man
Vote Green if you don't want to fly or drive anywhere and want to pay more tax.
Until a fairer voting system like 'Single Transferable Voting' is brought in (or put in a manifesto (hint) I will not be voting for a small party like yourself, because it simply would be a wasted vote.
Richard, Durham, UK
All very good but highly unrealistic. The big three parties stole the Green policies years ago and now the Green party has to radicalise itself to be different.
They know that their policies would lead to economic ruin, but that's not questioned, as they will never gain power. Glad to have their voice all the same.
John, Bristol, uk
Well done on a refreshingly radical and commonsense manifesto. I shall be voting green on May 5th having been totally disillusioned with the party in power.
Mike, Cockermouth, Cumbria
I am only 20 years old but I am already sick of the negative campaigning and sheer arrogance of all the other parties. Having read the Green pledges I am definitely going to Vote Green. These ideas are sensible, workable and important. Well done Mr Taylor, you've managed to change my mind about the Green party. Please continue and best of Luck
James Batten, Leeds
The Green policies would reduce pollution in the UK for certain as the economy would collapse so less cars, factories, consumer goods, hospitals and schools would lead to a 'cleaner' environment. Poverty however would exponentially increase.
I'm sure you would get more votes if you had more candidates - you haven't one in my constituency (Leeds North West). Good luck in the election anyway.
If we cut our CO2 emissions drastically, we are only helping to make the US multi-nationals (who aren't handicapped by Kyoto) more competitive. So, US companies will prosper, our industry will pay and our jobs will be lost all in a futile gesture that won't even reduce worldwide CO2 emissions.
I agree with previous calls for the Green Party to concentrate upon voting reform. It's not just the natural environment we should be worried about - its the political environment, too. I hope to see the first Green Westminster MP elected this May, and I'll feel proud that I had helped in achieving this, in accord with others who desire rapid change, and not self-preservatory procrastination.
G Duncan, Aberdeen, UK
The Greens would get my vote if they'd put up a candidate in my constituency. But as they haven't, it looks like I have the choice of wasting my vote or not voting.
Paul Thomas, Lichfield, Staffordshire
They're right that climate change is a bigger threat than terrorism, it could wipe out huge areas like Bangladesh - I just worry that the point-blank refusal to consider nuclear fuel means we are forced to rely on ineffective renewable sources.
Nuclear fuel got a bad rap from a few high-profile incidents and instead of continuing with heavily funded research, it's now the black sheep of the fuel family. Yet the first few cavemen probably burnt themselves with fire - imagine giving that up as too dangerous.
Pat B, London UK
Support for the Greens has been growing steadily over the past few years, but they really need to make their presence felt, and their standpoint on various issues known. They should push the fact that they intend to do something serious about our public transport, which compared to that of most European countries is an embarrassment. Housing will also be an issue - affordable housing is one thing, but seeing the large, detached, hardly energy-efficient, ugly box-like houses being thrown up everywhere, with every concession for the car owner made and no thought given to public transport links for the thousands of new inhabitants, I think the Greens should make it clear how their policy in this area differs from the other main parties. Keep up the good work - I'll be voting for you!
Pascale, Cambridge, UK
Go to it, Greens! Our experience here in Spain is that in the next year or two the incoming government will be implementing half of your policies!
Patrick Philpott, Córdoba, Spain
I come from New Zealand and we had a good sense to ditch the undemocratic Westminster System for Mixed-Proportion years ago. The current system in the UK allows the "big three" to get away with ignoring important issues. As long as the UK uses its current antiquated electoral system the Green Party will never hold any influence over national policy. Having minor parties that the majors may have to form a coalition with post-election encourages greater democracy and consultation with voters. Electoral reform must form a large part of the Green Party manifesto if they want their voice to be heard.
Craig, London - ex New Zealand
For all the talk, why aren't London buses running on BioDiesel, a carbon neutral fuel (that would prompt economic change for farmers).
Andy Iddon, London, UK
Keep with the Greens - Britain will thank you when C02 emissions are down.
Ralph, Gillingham, Kent
We must build for a sustainable future, our children's future mustn't be compromised by unsustainable development!
Get Caroline Lucas out there in the media as much as possible. She is the party's greatest asset - a brilliant debater and speaker.
Baz Tregear, Derbyshire, England
I will be voting for the Green party in May. They have put forward the most radical but workable ideas out of any party. What we need is change in this country and the Greens are the party to offer it.
David Coyle, Perth Scotland