(Bloomberg) -- KKR & Co. co-founder Henry Kravis pushed back against climate activists who interrupted a speech to criticize the firm’s fossil-fuel investments, saying they underestimate the difficulty of shifting the economy to clean energy. Most Read from BloombergRussia Is Sending Young Africans to Die in Its War Against UkraineMusk to Ban Apple Devices If OpenAI Is Integrated Into OSNYC Landlord to Sell Office Building at Roughly 67% DiscountInvestment Bank Moelis Probes Incident After Video