World leaders convene at COP31, the annual climate summit of the United Nations, held in Antalya, Turkiye from November 9 to 20, as global greenhouse gas emissions continue their upward trajectory. In 2025, a record 54.1 billion tonnes of greenhouse gases were emitted, marking a 0.7% increase over the previous year and a staggering 68.5% rise since 1990. The European Commission’s Joint Research Centre (JRC) and the International Energy Agency (IEA) released these figures, which highlight the significant role greenhouse gases play in trapping heat in the atmosphere and fueling extreme weather events such as heatwaves, droughts, floods, and other climate-related disasters. In 2025, carbon dioxide (CO2) accounted for 73.8% of global greenhouse gas emissions. The primary source of CO2 is the burning of fossil fuels like coal, oil, and gas, as well as deforestation that removes trees that would otherwise absorb CO2. Methane (CH4) was responsible for 17.6% of emissions, followed by nitrous oxide (N2O) at 5.3%, fluorinated gases (F-gases) at 3.3%, and other trace gases. Global CO2 emissions have risen by 76.3% since 1990, with the accumulation of these gases in the atmosphere leading to increased heat trapping and severe consequences such as the highest level of heat stored in the world’s oceans on record in 2025. Extreme weather events have claimed tens of thousands of lives and displaced millions in 2026, according to the World Meteorological Organization (WMO). In Europe alone, heatwaves, droughts, and wildfires between May and August caused over 30,000 excess deaths and forced more than 220,000 people to evacuate in France. Additionally, a glacier collapse and subsequent flash flood in the Himalayas killed over 1,500 people in Nepal in August, while about 5,600 remain missing. The power industry, which generates electricity, is the largest source of global greenhouse gas emissions, accounting for nearly 30% in 2025. Its emissions have quadrupled since 1970 due to soaring demand for electricity in fast-growing economies such as China and India. The second-largest source is industry, including manufacturing and mining (21%), followed by transport (16%), agriculture (12%), the extraction of coal, oil, and gas (11%), buildings (6.6%), and waste (3.6%). The world’s greenhouse gas emissions have more than doubled since 1970, rising from about 23 billion tonnes to 54.1 billion tonnes in 2025. The power industry, the primary contributor to global emissions, has driven this increase. China (29.5%), the United States (11.1%), and India (8.3%) were the three largest emitters in 2025, accounting for almost half of the world’s greenhouse gas emissions. The European Union, Russia, Indonesia, Brazil, Iran, and international shipping and aviation (which fall outside any single country’s total) also contributed significantly to global emissions. The Industrial Revolution in the 18th and 19th centuries first drove up emissions in the West, particularly in the United Kingdom and the US, as they built factories and moved towards mass manufacturing. After World War II, global emissions rose sharply and have more than doubled since 1970. China’s emissions surged in the early 2000s as its economy boomed, overtaking the US as the world's largest emitter in the mid-2000s. However, when viewed over time, the picture changes, with the rise and fall of major contributors to global greenhouse gas emissions.