An estimated £75bn of private sector investment is needed to ensure London meets its target to be carbon neutral by 2030, the capital's mayor has said.
Sadiq Khan said London needed to go "much further, much faster" to meet its net zero goal.
Mr Khan added London's economy was hit by the July heatwave when temperatures reached a record breaking 40C (104f).
The number of workers and visitors plunged, with footfall dropping to 76% of June's figures.
He said there were 385,640 daytime workers when 518,000 workers would usually be expected and only 275,000 daytime visitors came to central London on the same day when about 361,000 people would be expected.
Speaking to the Reuters IMPACT Conference, he said: "For the first time ever, London overheated."
The heatwave saw wildfires breakout across London, and homes were destroyed by fires sparked by the heat.
"When we look back at this period of history, no-one will be able claim with any credibility that we were not given fair warning - that we could not see disaster bearing down on us," he added.
He said the required investment could not be delivered without the private sector.
Addressing business leaders he said: "I know you're all dealing with inflationary pressures right now, but there are huge opportunities and rewards to be seized by accelerating our efforts to achieve net zero by 2030."
Mr Khan added that while mayor, his Green New Deal had created investments in green jobs, skills and infrastructure in London.
He said under his leadership, the capital had delivered a fivefold increase in protected cycling lanes, put more electric and hydrogen powered buses on roads, cleaned up the taxi fleet and delivered hundreds of new electric vehicle charging points.