(Bloomberg) -- For John Arnold, the billionaire philanthropist who made his fortune betting on natural gas prices, Houston’s fossil-fuel industry seems finally ready to move on.A year ago, talk in the Texas energy hub was mostly about defending oil and gas and denouncing renewables, Arnold, 47, said Monday on his Twitter account. Now, much of the discussion has shifted to clean-energy topics including wind, solar and batteries.“Even those who are not ideological believers are taking the cues from the financial markets, which have no interest in oil production growth anymore,” said Arnold, the former head of natural-gas derivatives at Enron Corp.He also said capital available to oil and gas has dried up while “every” private equity firm in Houston is raising money for clean energy. “The markets are rewarding those in a growth industry (zero carbon energy) vs one in secular decline.”Arnold said the shift has made him more optimistic about the speed of decarbonization, which requires the scale and financial resources that large companies possess. “The fossil fuel industry has that expertise and is now focusing on a low carbon future.”Arnold founded hedge fund Centaurus Advisors LLC in 2003 after leaving Enron, and the Houston-based fund gained fame betting against Amaranth Advisors LLC, which collapsed in 2006 after losing $6.6 billion on bad bets in the natural gas market. He closed the fund in 2012 at age 38 to pursue philanthropy with his wife Laura Arnold, a lawyer and former oil company executive, with the couple extending their influence through Arnold Ventures out of Houston.(Adds Arnold background in last paragraph.)For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.