President Biden and Vice President Kamala Harris kicked off the virtual international climate summit on Thursday, Earth Day, at 8 a.m. with remarks that highlighted the importance of global efforts to reduce carbon emissions. Pope Francis will speak on the same topic later.
Here is a breakdown of the biggest names and the topics they will address over the next two days.
Economics and Pope Francis
Treasury Secretary Janet Yellen and David Malpass, the World Bank president, who has recently expressed support for a net-zero carbon future, joined a morning session on financing climate change solutions. Later, speakers will highlight climate work on the local level and discuss security challenges posed by global warming.
On Thursday afternoon, Agriculture Secretary Tom Vilsack and Homeland Security Secretary Alejandro N. Mayorkas will participate in a panel to discuss the logistical challenges climate change poses for government agencies.
The pope is scheduled to appear via video link sometime during the session that began at 10:30 a.m. In 2015, he published a treatise calling for countries to “care for our common home” and to accept scientific conclusions about human-induced global warming.
International security and geopolitics
On Thursday afternoon, Defense Secretary Lloyd J. Austin III; the director of national intelligence, Avril D. Haines; and Ambassador Linda Thomas-Greenfield, the U.S. representative to the United Nations, will participate in a panel on the international security implications of climate change with the Japanese defense minister, Nobuo Kishi, and Secretary General Jens Stoltenberg of NATO.
On Friday, John Kerry, Mr. Biden’s top climate envoy, and Prime Minister Benjamin Netanyahu of Israel will join a session on the importance of technological innovation in reducing carbon emissions.
Opportunities for businesses
On Friday, the secretary of transportation, Pete Buttigieg; the United States trade representative, Katherine C. Tai; and Mr. Biden’s climate advisers will convene a panel exploring “the economic benefits of green recovery and long-term decarbonization.” The panel will also include business leaders and union officials.
Former Mayor Michael R. Bloomberg of New York, a billionaire who has bankrolled climate-related groups, will speak later in the day.
Bill Gates, the Microsoft founder, will also speak as the founder of Breakthrough Energy, an investment fund that supports projects to reduce carbon emissions.
Which world leaders are attending?
President Xi Jinping of China, the United States’ biggest rival on the world stage, is attending the virtual summit. So are Presidents Vladimir V. Putin of Russia and Jair Bolsonaro of Brazil, with whom the Biden administration is trying to negotiate a plan to protect the Amazon rainforest.
A number of prominent American allies have spoken, including Prime Minister Boris Johnson of Britain and Chancellor Angela Merkel of Germany. Other key attendees include Prime Minister Narendra Modi of India, President Moon Jae-in of South Korea and Prime Minister Yoshihide Suga of Japan — leaders from whom the Biden administration has been trying to secure commitments on emission reduction targets.
King Salman of Saudi Arabia, President Recep Tayyip Erdogan of Turkey and President Andrés Manuel López Obrador of Mexico are also attending. The White House has invited more than 40 world leaders in total.
What actions might be taken?
Mr. Biden announced that the United States intended to cut planet-warming emissions in half by the end of the decade, a target that will require Americans to transform the way they drive, heat their homes and manufacture goods.
This nearly doubles the pledge made by the Obama administration, and the Biden administration hopes the announcement will galvanize other nations to increase their own targets.