Video report by ITV Science Editor Tom Clarke
What are the manifesto's key pledges?
The left-wing party has announced 10 new laws that would be ready to be implemented if co-leaders Sian Berry and Jonathan Bartley won an against-the-odds majority on December 12.
The focus of the bills would include the so-called Green New Deal, a People’s Vote, NHS reinstatement, higher education, a more sustainable economy and a future generations bill.
Here's more detail on the manifesto's key measures:
£100 billion annual investment to make UK carbon neutral by 2030
The manifesto pledges an, already announced, £100 billion per year investment plan to deliver a Green New Deal over the next 10 years.
It would look to totally overhaul the use of fossil fuels by switching transport and industry to renewable energy sources, while upgrading household heating systems and planting 700 million trees within a decade.
The party wants to use the measures to create a net-zero carbon economy by 2030.
Under the party’s plans, it would raise £91 billion a year for the next decade for capital expenditure on tackling climate change.
A further £9 billion a year in operational spending would be funded through raising taxes, including corporation tax which would rise to 24%.
Hold a second referendum and campaign for Remain
The pro-European Union party has re-committed itself to a second referendum and to campaign for Remain.
It says staying in the bloc would help “lead the fight against the climate emergency”.
Make misogyny a hate crime and decriminalise some Class A drugs
Misogyny would be made a hate crime under a Green-led administration and the personal use of drugs, including some Class A substances, would be de-criminalised.
Heroin would be available on prescription and cannabis clubs would be permitted, allowing marijuana to be grown and consumed by adults.
Restorative justice would be expanded to allow those affected by crimes to meet offenders as part of a bid to cut the prison population by 50%.
Introduce a universal basic income and build 100,000 new council houses
The Greens would introduce a universal basic income, providing every UK citizen with £89 per week in state funding.
It would provide a boost to those in work and leave no-one on benefits worse off, according to the manifesto.
Ms Berry also pledged that 100,000 new energy-efficient homes every year for social renting would be built as part of a renters’ rights bill.
Increase NHS funding by £6 billion each year
Party leaders have promised to increase funding for the NHS by at least £6 billion each year until 2030 – a 4.5% increase on the 2018/19 budget.
Privatisation in the NHS would also be abolished, while mental health care would be put on an “equal footing” with physical care.
Spend at least £4 billion a year on education and replace Ofsted
The party pledges to boost education funding by at least £4 billion per year and to lay down a long-term aim of reducing classes to 20 pupils and below.
Ofsted would be replaced with a “collaborative system of assessing” schools and a new law would put onus on teaching children about climate change.
In higher education, tuition fees would be scrapped and those who paid £9,000 a year to study would have their debt wiped.
Lower the voting age, elect the Lords and go to PR voting system
The Greens would also scrap the first-past-the-post voting system and replace it with proportional representation, create a fully elected House of Lords and extend voting rights to 16 and 17 year-olds.
Ms Berry said that a voting reform bill would also “give us a real democracy at last”.
ITV News Analysis: Can voters look beyond mind-blowing cost of decarbonising our economy?
One hundred billion pounds a year?!
In fact, their spending plans are perfectly credible, if you look at the stark realities of the economics of climate change...
The key quotes from the Green Party leadership
Speaking at the official launch of the party manifesto at the London Wetlands Centre, co-leader Jonathan Bartley promised that the green new deal would be the most ambitious in the world.
Mr Bartley said that the issue of climate change had been overshadowed by financial crises, but those responsible had been “let off the hook”.
“Hitting snooze for another 15 years simply isn’t an option. This is a different magnitude to the financial crash," he said.
“You can’t double down on business as usual, pray to the markets and expect the climate emergency to magically go into reverse.”
On Brexit, deputy leader Ms Womack said that voting Green was the strongest way to ensure that Britain was kept in Europe.
“We are offering the only way forward from the wreckage of the 2016 referendum. We are not going to watch while story extremists drive our country off a cliff,” she said.
“Greens are different. We will give you a people’s vote, your final say on Brexit.”
Ms Berry said that each elected Green MP would have 10 bills ready to put forward to ensure that the next parliament “hit the ground running”.
“The future will not give us another chance to get these next two years right,” she said.