Petrochina’s total GHG emissions saw an annual decline of 5% in 2021. China's largest oil and gas producer, PetroChina (601857.SS), said on Thursday it aimed to have renewable energies make up one third of its energy portfolio by 2035 and 50% by 2050.PetroChina was estimated to have released 881 million metric tons of carbon dioxide equivalent (MtCO2) in 2019. PetroChina is one the largest oil companies worldwide.State-owned PetroChina plans to spend about Yuan 10 billion ($1.49 billion) annually in the next five years for low carbon emission transitions as part of the company's effort to meet Beijing's call for carbon neutrality by 2060, Wei Fang, Assistant Secretary to the Board & Head of Investor Relations, said during the company's Q3 result briefing.