The United Nations held a climate conference in Dubai, during which countries made the unprecedented decision to gradually shift away from relying on fossil fuels. The emissions from these fuels have contributed to the planet’s record-breaking high temperatures in the past year.

Axios initially broke the news that Kerry will be assisting in Biden’s bid for reelection. Following suit, Mitch Landrieu, the infrastructure czar for Biden, also declared his departure from his role to join the campaign team. Kerry’s departure comes at a critical point for U.S. climate diplomacy, as well as during a time where a second term for former President Donald Trump poses the greatest risk to Biden’s climate agenda.

Kerry, who is 80 years old, has been a constant presence in the United States’ efforts towards climate diplomacy for many years. Prior to this, he was a senator and had proposed a significant climate bill during the early years of the Obama administration. He was so passionate about advocating for climate action that a fellow Democrat described him as being solely focused on the issue in 2010.

After five years, while serving as Secretary of State under Obama, he played a role in brokering the Paris climate deal. This agreement outlined a system where nations would individually commit to reducing their emissions of harmful greenhouse gases. The agreement aimed to limit the increase in average global temperatures to no more than 2 degrees Celsius above pre-industrial levels, with a more ambitious goal of 1.5 degrees also included.

He established a close connection with Xie Zhenhua, the chief climate negotiator for China, who is rumored to also be stepping down from his position. The bond between the two experienced diplomats often resulted in agreements between the world’s leading emitters of greenhouse gases to address pollution, despite the challenges of maintaining progress on climate issues in the face of growing tensions between the United States and China.

Senator Ed Markey, who now holds the Senate seat previously held by John Kerry, wrote on Saturday on X that Kerry was an extraordinary diplomat, not just for our nation, but for the entire world.

Kerry was instrumental in reaffirming the United States’ leadership in addressing climate change on the world stage following four years under Trump. He brought a respected and dedicated approach to upholding the international climate framework, which he had a significant role in shaping.

“He played a key role in restoring the United States’ reputation in regards to climate change and motivating other nations to intensify their initiatives. His influence is evident in the heightened activity we have witnessed in recent years,” stated Jake Schmidt, senior strategic director for international climate at the Natural Resources Defense Council, in a text message.

David Waskow, the director of international climate at the World Resources Institute, stated that this undoubtedly signifies the conclusion of a significant period.

He recalled seeing Kerry discuss with delegates from island nations during the 2007 U.N. climate summit in Bali, Indonesia, back when Kerry was a senator for Massachusetts. “It was evident that he was concerned about their situation and comprehended the necessary steps to combat climate change.”

In the upcoming year, countries are anticipated to reach a consensus on a fresh objective for providing climate-related funding to developing nations in order to assist them in dealing with the impacts of climate change and promoting the use of cleaner energy sources. This is a particularly challenging topic, as the U.S. has received criticism for not fulfilling previous commitments.

Rich countries failed to meet a goal they set in 2009 to amass $100 billion in annual climate finance by 2020, a figure that experts say is modest compared to the trillions of dollars that will be needed to keep temperatures rises in check.

According to Waskow, the administration must prioritize those negotiations and not let Kerry’s departure cause them to be ignored.

Kerry has advocated for multiple solutions to increase necessary assistance for developing nations, such as utilizing funding from companies and global organizations like the World Bank.

He simultaneously spearheaded the U.S.’s resistance against suggestions made by certain developing countries that would hold nations like the United States accountable for the permanent damages caused by their long-standing climate pollution. Instead, in 2022, the U.S. concurred to the establishment of a fund for “loss and damage” caused by climate change to aid less affluent nations, while maintaining that donations from wealthier governments would be optional.

In the previous year, the United States promised to contribute $17.5 million to the fund in Dubai. However, this amount is significantly lower than the contributions made by smaller countries such as Italy, Germany, and the United Arab Emirates. Additionally, there is uncertainty about whether the U.S. will be able to fulfill this promise due to strong opposition from the Republican party.

In the past, Kerry has avoided pressure from activists to have the U.S. government invest a significant amount of money into the fund. During a forum in 2022, he stated that he remains realistic about the situation.

Despite the debates and disagreements about financial matters, Kerry remains hopeful that the global community can decrease its greenhouse gas emissions quickly enough to avoid disaster.

Kerry expressed a greater interest in finding solutions to eliminate emissions and achieve victory in the battle, stating that it is achievable.

Nate Hultman, a former senior adviser to Kerry, credited the envoy not only with navigating the complex negotiations at last month’s COP28 climate talks but with the work he’s done to cut the oil and gas industry’s emissions of methane, a greenhouse gas with far more warming potential than carbon dioxide.

“I believe that he is leaving behind a remarkable legacy,” stated Hultman, who currently serves as the director of the Center for Global Sustainability at the University of Maryland.

This report was contributed to by Sara Schonhardt.