WASHINGTON (AP) — Vice President Joe Biden on Tuesday made his first public appearance since burying his oldest son earlier this month, thanking major foundations and institutional investors for pledging to spend more than $4 billion on new technologies to reduce climate change pollution.

Wearing a black suit and reading for the most part from a teleprompter, Biden made no comment about his family’s loss.

He stuck to the issue at hand during 27 minutes of remarks at the close of a White House summit on clean energy, but he tossed out a few jokes along with mentions of his brother and late mother.

Biden even brandished a copy of Tuesday’s edition of The Washington Post, which had as its lead story a report on a draft of Pope Francis’ eagerly awaited encyclical on the environment. In the draft document, the pope calls for urgent action to combat global warming, saying it is “mostly” due to human activity and the burning of fossil fuels.

“There is a consensus growing” around the need for action, the vice president said.

Hundreds of organizations, ranging from the University of California, the Goldman Sachs investment firm and the Sierra Club Foundation, have committed to help pay for “innovative technologies” that show potential for reducing carbon pollution, the White House said.

The White House also announced other actions to encourage the private sector to invest in these technologies, including making information about the Energy Department’s and other government energy and climate programs more available and understandable to the public.

Biden’s son Beau Biden, the former attorney general of Delaware, died of brain cancer at the end of May at age 46. He was buried on June 6 in Wilmington, Delaware, after a funeral that was attended by scores of political luminaries. President Barack Obama delivered the eulogy.

Biden has stayed in Wilmington with family since his son’s death, but last week made a few trips to the White House to attend private meetings and keep his regular lunch date with the president. Biden returned to Delaware after each trip although he has an official residence at the Naval Observatory in Washington.

Jill Biden, Biden’s wife and Beau’s stepmother, spoke over the weekend at a Navy ceremony in Alabama.