The document discusses global energy use and carbon emissions. It notes that the current energy system is heavily reliant on fossil fuels, producing over 30 billion tonnes of CO2 emissions annually. While renewable energy is growing, it still accounts for a tiny fraction of global electricity generation compared to coal, gas and oil. The document argues that a major transition is needed to limit global warming, through improving energy efficiency, expanding renewables and nuclear power, electrifying transport, and developing carbon capture and storage. However, large-scale changes will take time due to infrastructure lifetimes and the gradual pace of technological adoption. Scenarios projecting pathways to lower emissions by 2050 involve coordinated international efforts to gradually transform energy systems over decades.