Deputy Mayor of Environment Shirley Rodrigues said the "first single environment strategy for London" tackles air quality, energy, water and green infrastructure.
The big target is to make more than half of London's area green, with 10% more tree canopy by 2050.
She said a £9m fund to run over London mayor Sadiq Khan's term will help plant more trees and "enhance quality greenspace" working with boroughs and NGOs to achieve this.
A new map will identify areas with a lack of green space.
Green walls, green roofs and SuDS are a focus. Rodrigues says since 2008 a London Plan green roofs planning policy has meant 1m sqm of green roofs being created including at 700 sites in central London. She said this shows "how successful" planning policy can be.
The new London Plan will make sure large housing developments include green roofs and walls, said Rodrigues.
She said the funding was available for local authorities to come forward with ideas for retrofitting as well as for new green space and that it complemented the new £85m Liveable Neighbourhoods Programme, which encourages boroughs to bid for funding for long-term schemes that encourage walking, cycling and the use of public transport.
She said there had been conversations with Metro mayors on these areas and that she hopes the London plans will "set a template" for the rest of the UK.
The strategy supports the London park city recommendation by the GLA environment committee.
London Mayor Sadiq Khan announced the new £9 million Greener City Fund for London on 11 August. Local groups can apply for the first £1m of grants to plant neighbourhood trees and maintain green community areas.
The Mayor made the announcement as he launched the draft Environment Strategy for consultation at Woodberry Wetlands in Hackney, alongside the London Wildlife Trust.
The strategy's executive summary says: "More walking and cycling, and fewer vehicles on the street, help reduce traffic noise, improve air quality and reduce carbon dioxide emissions.
"Energy efficient buildings and local energy generation will reduce carbon dioxide emissions and improve air quality.
"Green spaces support biodiversity. They improve health and well being by providing tranquil places to relax in, and places to play, exercise, and socialise in.
"Green roofs and walls help insulate buildings, reducing energy demand. They also support biodiversity, help reduce flood risk, and help improve air quality.
"Green and healthy routes to and from schools can help reduce people’s exposure to air quality.
"Sustainable drainage helps reduce flooding and improves water quality.
"Trees provide shade and help cool the city. Rainwater harvesting will help reduce
water demand. Recycling and generating energy from waste will help reduce pressure
on resources and landfill."
The chapter on green infrastructure pledges to:
Make London the first National Park City, including providing a Greener City Fund to support communities to plant more trees and improve green spaces
Increase and improve green infrastructure in areas where Londoners, especially children, have the least amount of green space
Use a new Urban Greening Factor to make sure that new developments are greener
Protect London’s Green Belt from further development
Set up a London Green Spaces Commission to roll out new ways for the Mayor, London boroughs, community groups and others to fund, manage and value green spaces and nature
Identify the true economic value of London’s green spaces through a Natural Capital Account
Use the planning system to protect London’s biodiversity, offsetting any reductions caused
by new developments with increases elsewhere.
The report states: "This radical new approach requires a fundamental change to the way London thinks about its parks and green spaces. Unlocking the value of green infrastructure will help to mitigate the decline in quantity and quality of London’s green spaces, improving the lives of everyone who calls the city their home."
The Mayor’s strategy proposals are designed to help London towards this goal and the aim of launching London as a National Park City at an international Summit in Spring 2019. His proposals include:
- Creating a ‘Challenge Map’ to highlight areas of London that should be priorities for green infrastructure investment as part of the Mayor’s target to make more than 50 per cent of London green by 2050
- Setting up a Green Spaces Commission to work with environmental experts to help boroughs attract investment, and transform and preserve their parks and green spaces
- Developing a new ‘Urban Greening Factor’ to ensure that green roofs, green walls – walls which are covered in plants and grass often by busy road sides and help lower pollution, trees and rain gardens are incorporated into new developments in London. The Mayor will also use his planning powers to protect our Green Belt and Metropolitan Open Land
- Targeting ‘grey’ areas to make them greener. With more Londoners living in flats and working in high rise offices, and with fewer people having access to private gardens, the Mayor wants to ensure more streets and public spaces become greener to improve health and encourage more walking and cycling.