"The Kingdom of Saudi Arabia aims to reach zero-net emissions by 2060 under its circular carbon economy programme ... while maintaining the kingdom's leading role in strengthening security and stability of global oil markets," Prince Mohammed said in recorded remarks.
He said the kingdom would join a global initiative on slashing emissions of methane by 30% from 2020 levels by 2030, which both the United States and the EU have been pressing.
U.S. climate envoy John Kerry is due to attend a wider Middle East green summit Riyadh is hosting on Monday.
Saudi energy minister Prince Abdulaziz bin Salman said Riyadh, a signatory to the Paris climate pact, had already submitted its nationally determined contributions (NDCs) - goals for individual states under global efforts to prevent average global temperatures from rising beyond 1.5 degrees Celsius above pre-industrial levels.
The SGI aims to eliminate 278 million tonnes of carbon emissions per year, the crown prince said, up from a previous target of 130 million tonnes.
Saudi Arabia in March pledged to reduce carbon emissions by more than 4% of global contributions. It said that would involve generating 50% of its energy needs from renewables by 2030 and planting billions of trees in the desert state.
HYDROCARBONS STILL NEEDED
Saudi Arabia's economy remains heavily reliant on oil income as economic diversification lags ambitions set out by the crown prince.
Saudi officials have argued the world will continue to need Saudi crude for decades to come.
"The world cannot operate without hydrocarbon, fossil fuels, renewables, none of these will be the saver, it has to be a comprehensive solution," the energy minister said.
"We need to be inclusive and inclusivity requires being open to accept others efforts as long as they are going to reduce emissions," he said, adding that the kingdom's young generation "will not wait for us to change their future".
He said the net zero emissions target might be achieved before 2060 but the kingdom needed time to do things "properly".
Fellow Gulf OPEC producer the United Arab Emirates this month announced a plan for net zero emissions by 2050.
The chief executive of UAE oil firm ADNOC, Sultan al-Jaber, also stressed the importance of investment in hydrocarbons, saying the world had "sleepwalked" into a supply crunch and that climate action should not become an economic burden on developing nations.
Saudi Arabia has been criticised for acting too slowly, with Climate Action Tracker giving it the lowest possible ranking of "critically insufficient".
And experts say it is too early to tell what the impact of Saudi's nascent solar and wind projects will be. Its first renewable energy plant opened in April and its first wind farm began generating power in August.
Megaprojects, such as futuristic city NEOM, also incorporate green energy plans including a $5 billion hydrogen plant, and Saudi state-linked entities are pivoting to green fundraising.
Some investors have expressed concerns over the kingdom's carbon footprint. Others say Saudi Arabia emits the least carbon per barrel of oil and that de facto ruler Prince Mohammed is serious about economic diversification.
"Obviously the carbon footprint is an issue. However, we would highlight that realistically carbon is going to be slow to phase out, and oil is here for some time yet," Tim Ash at BlueBay Asset Management said in emailed comments.
(Reporting by Yousef Saba and Saeed Azhar in Riyadh, Marwa Rashad in London and Maher Chmaytelli in Dubai; Additional reporting by Raya Jalbi in Dubai; writing by Ghaida Ghantous; editing by Nick Macfie and Jason Neely) ((firstname.lastname@example.org))