Sadiq Khan has pledged to support more than 170,000 green jobs if re-elected as mayor.
The Labour mayoral candidate wants to create jobs in flood risk areas of the capital and roles in electrifying London's bus fleet.
Mr Khan has described the upcoming election as "a two-horse race" against Conservative mayoral candidate Shaun Bailey.
The election for Mayor of London will take place on 6 May.
LONDON'S ELECTION: THE BASICS
- What's happening: On 6 May people will vote to elect a mayor as well as 25 members of the London Assembly. Together, they make up the Greater London Authority (GLA), which governs the capital - you can register to vote here.
- What difference does it make? The mayor has a £19bn budget and is responsible for Transport for London, the Metropolitan Police, and has a role in housing, planning and the environment. The London Assembly holds the mayor to account by examining policies. Find out more here.
- Who is standing? London's current mayor, Labour's Sadiq Khan, is seeking re-election and his main challenger is Conservative Shaun Bailey, but there are 18 others running.
Ahead of his manifesto launch at the Bloomberg building in central London, Mr Khan reflected on the affect of the coronavirus pandemic on the capital.
"The pandemic has had a devastating impact on London but I know that a brighter future lies ahead and together we can rebuild a fairer, greener and more prosperous city," he said.
"If re-elected a top priority will be jobs, jobs, jobs.
"Good, high-quality jobs for Londoners in future proof sectors such as the green economy which allow us to tackle the climate emergency alongside the looming unemployment crisis."
Details of Mr Khan's manifesto include a pledge for a £50m New Green Deal.
A ten-point plan includes ambitions of the capital becoming a carbon neutral city by 2030 and "ensuring London's transport system is the world's greenest".
His plan also includes a scheme to create 3,000 new jobs in electrifying the city's bus fleet, 4,400 jobs in solar energy and 1,7000 in district energy.
Mr Khan also announced plans to review examining decriminalising cannabis.
If elected, Mr Khan said he would he would set up an independent London drugs commission to examine the potential health, economic and criminal justice benefits of decriminalising the class-B drug.
The mayor of London has no powers to change drug legislation, but they officially act as the police and crime commissioner for London. This means the mayor has a role in setting out how London is policed and staffed.
Mr Bailey said: "In 2016, he [Sadiq Khan] pledged thousands of new jobs. He delivered just 109. He promised to be the most pro-business mayor ever. Yet he hiked the congestion charge in the middle of a pandemic.
"I'll take practical action to clean up the environment with a zero-emission bus fleet by 2025. And I'll reverse the congestion charge hike on day one, helping to cut bills for workers and job-creators."
Green Party candidate Sian Berry said: "This focus for the current mayor's manifesto launch shows the huge influence Greens have had in the past five years.
"London could be the greenest city in the world, but only a real Green mayor will get us there."
Luisa Porritt, the Liberal Democrat candidate for mayor, said: "One thing Sadiq Khan won't be talking about today is his £2bn polluting Silvertown Tunnel road project.
"It's the Mayor's dirty little secret and makes a complete mockery of his self-professed green credentials."