Malpass, who worked as Bear Stearns’ chief economist before becoming the under secretary of the treasury for international affairs for the United States under the Trump Administration, was appointed World Bank president in 2019. At the helm of the world’s humanitarian financial institution with $7.9 billion in capital, he’s remained tight-lipped about climate change, while funding sustainability-focused projects around the world. 

“To have a climate denier who was named by the previous president—also a climate denier—in charge of America’s lead institution and helping to deal with the dimensions of this global capital allocation problem is ridiculous,” Gore said at Fortune‘s Global Sustainability Forum on Thursday. “That’s why he needs to be replaced immediately.”

Unlike Malpass, Gore has made his post-presidential administration career about climate activism. Since serving as former President Bill Clinton’s vice president and a failed 2000 presidential run, Gore has committed to climate advocacy. Following the release of his 2006 Oscar-winning climate documentary An Inconvenient Truth, Gore won the 2007 Nobel Prize for his activism. Since then, he’s become a vegan, climate-focused partner at blue-chip venture capital firm Klein Perkins and the founder of the Climate Reality Project and Generation Investment Management. Recently, he’s expressed optimism for the climate with the passage of the Inflation Reduction Act, Australia’s Climate Change bill, and dismay at Malpass. 

Under Malpass’s tutelage, the World Bank recently released $300 million to Cameroon, $512 million to Turkey, and $335 million to Tanzania to fund climate-resilient infrastructure projects, among other initiatives.

The drama between the two politicians is unfolding to the soundtrack of climate catastrophes: Hurricane Ian has devastated Southwestern Florida, flooding in Pakistan has displaced more than 33 million people, and researchers found that flaring—the practice of burning planet-warming methane—is far less effective than everyone thought. These events are just samples of fires, floods, hurricanes, and so on that characterize the effects of climate change. 

In response to Fortune’s request for Malpass to respond to Gore’s remarks at the Global Sustainability Forum, a World Bank representative pointed to Malpass’s remarks on September 28 at Stanford University, where he said, “Developing countries are being hit by more frequent and more severe climate-related disasters. Man-made greenhouse gas emissions are causing climate change, which in turn, is having tragic impacts on development in multiple ways.”

When Gore called Malpass a “climate denier” at a New York Times event last week, Malpass called Gore’s attack “very odd,” but declined to answer questions about whether he accepted climate science. 

“It’s really, really bad,” the former vice president said Thursday in conversation with journalist-turned-climate venture capitalist Molly Wood. “Under his leadership, he has directed continued funding of fossil fuels, which is ridiculous.”

In addition to his comments about Malpass, Gore also drew distinctions between capitalism and climate disaster at the Fortune forum. He said that capitalism is not “the problem or cause” of the climate crisis. Rather, he said he believes in a brand of multi-stakeholder capitalism to alleviate the climate crisis and provide developing countries with sustainable energy, food, and production mechanisms that can slow the devastation.