OMAHA, Neb. (AP) — Before billionaire Warren Buffett takes the stage Saturday to spend hours answering at his conglomerate's annual meeting, his investors had to weigh questions about climate change and disclosing political contributions.

The type of measures Berkshire Hathaway shareholders face are becoming more common as groups push for change at companies both in the way they operate and in how they're governed.

This year Berkshire shareholders will vote on proposals requiring the sale of fossil fuel investments, a report disclosing details of political contributions and a report on its efforts to reduce methane emissions.

Those three are part of a record 470 proposals submitted to public companies this year, according to advocacy groups that track them. That's up from 370 last year and the previous record of 433 in 2015.

Not all of those will make it to a vote because some are disqualified and companies often respond after seeing proposals, prompting some to be withdrawn. Roughly 250 are scheduled to be voted on at annual meetings this spring.

"We find that boards are increasingly willing to engage with investors," said Sean Quinn, the head of U.S. research for Institutional Shareholder Services that advises investors how to vote on these measures.

The resolutions offer a tool for investors to force companies to address a topic, and in the age of social media the measures are becoming more successful, said Andrew Behar, CEO of the As You Sow advocacy group that tracks and supports such proposals. As You Sow is also backing 51 proposals this year at various companies.

"Companies are really aware of their brand image," Behar said. "There's greater sensitivity now."

Shareholder proposals generally face long odds, but they can still lead to changes at companies even if the vote totals don't appear impressive. The odds of success are especially long at Berkshire if Buffett opposes a measure because he controls about one-third of the vote and he's revered by many shareholders.

Buffett and Berkshire's board oppose all three shareholder measures this year. The board argues that both the proposed reports are unnecessary and selling off stocks tied to fossil fuels could hurt Berkshire's investment returns.

But even if these measures fail, they let groups make a public statement about an issue they care about, and Berkshire's meeting offers a prominent stage because it draws more than 30,000 people who want to listen to Buffett and his Vice Chairman Charlie Munger field questions for most of Saturday.

Tim Rinne with Nebraskans for Peace said the group's members hope they'll be able to change Buffett's mind because he could be powerful advocate for fighting climate change, but they also appreciate the chance to speak to the large crowd about divesting stocks linked to fossil fuels.

"Everybody comes to Omaha because they want to know what Warren thinks," Rinne said.

Shelley Alpern with the Clean Yield Asset Management will be urging Berkshire shareholders to support more disclosure of the political contributions the conglomerates more than 90 businesses make. Alpern said more than 300 other companies have already adopted the approach she's pushing for, and she appreciates having the resolution process to press the issue.

"It is a very useful tool," Alpern said. "The fact that shareholders can file resolutions doesn't make certain business groups happy."