At an event at Cop26 in Glasgow alongside the Prince of Wales, French President Emmanuel Macron and European Commission President Ursula von der Leyen, the billionaire said he would match a previous contribution made through his Bezos Earth Fund.
The fund has pledged 10 billion dollars (£7 million) to tackle climate change.
The event centre around the Great Green Wall initiative, which aims to plant more than 20 million trees across 8,000 kilometres traversing the width of Africa to counter desertification on the continent.
He told attendees, who also included the president of Nigeria, the president of Mauritania and representatives of the World Bank and African Development Bank, action must to be taken to ensure the next decade is not one that is seen as “indecisive”.
“Last month, I committed a billion dollars in grants to support nature conservation and will be starting with the Congo basin countries and the tropical Andes,” he said.
“Tomorrow we will be making an equivalent commitment to landscape restoration with a major focus on Africa.
“We want to work with the major platforms that are already established and ready for scaling, including Africa 100 and the Great Green Wall.”
He added: “We all know that this is the decisive decade, but without action, it will become the indecisive decade.
“We can’t let that happen.
“Please consider us an ally for this important cause.”
Mr Bezos drew criticism from climate activists earlier this year after using a project he funded to go to space.