What causes climate change

Overview

Climate change results from an imbalance in Earth's energy system caused primarily by human activities. Since the Industrial Revolution, burning fossil fuels has released massive amounts of greenhouse gases into the atmosphere. These gases trap heat from the sun, causing global temperatures to rise at an unprecedented rate.

Fossil Fuel Combustion

Burning coal, oil, and natural gas is the largest contributor to climate change, accounting for approximately 75% of global greenhouse gas emissions. Fossil fuels power electricity generation, heating systems, transportation, and industrial processes worldwide. Each ton of fossil fuel burned releases carbon dioxide that persists in the atmosphere for centuries, continuously trapping heat.

Atmospheric Greenhouse Gases

Greenhouse gases absorb and re-emit infrared radiation, trapping heat in Earth's atmosphere. Carbon dioxide (CO2) is the most abundant, comprising about 75% of emissions. Methane (CH4) is far more potent—25-28 times more heat-trapping than CO2 per molecule. Nitrous oxide (N2O) from fertilizers is 298 times more potent than CO2. These gases remain active for decades to centuries.

Deforestation and Land Use

Forests act as carbon sinks, absorbing CO2 during photosynthesis. Deforestation removes these natural absorbers while releasing stored carbon through burning and decomposition. Agriculture, particularly livestock raising, contributes through land clearing and methane emissions from cattle digestion. Wetland drainage releases methane from decomposing organic matter.

Industrial and Agricultural Emissions

Manufacturing processes, cement production, and chemical industries emit significant greenhouse gases. Livestock agriculture contributes through methane from ruminant digestion and manure management, plus nitrous oxide from manure and fertilizers. Industrial agriculture also drives deforestation. These sectors collectively represent about 25% of global emissions.

Feedback Loops and Acceleration

Climate change triggers feedback loops that accelerate warming. Melting ice and snow reduce Earth's reflectivity (albedo), causing more heat absorption. Thawing permafrost releases methane. Warmer oceans absorb less CO2. These feedback mechanisms mean warming continues even if emissions stabilize, making swift action critical to prevent catastrophic climate impacts.