Caltech Science Exchange / Topics / Sustainability / Emissions

Where Do Greenhouse Gas Emissions Come From?

While greenhouse gases are naturally occurring, human activities such as burning fossil fuels and making concrete emit them in large quantities. What are greenhouse gases? What activities cause the most emissions? And why are scientists and policymakers concerned? The comic below breaks it down.

Greenhouse gases in the atmosphere

What are greenhouse gases?

Where do greenhouse gas emissions come from?

Greenhouse gases come from industry, agriculture, and commercial residential

Cement is responsible for 8% of the world's CO2 emissions

Using specialized airborne and remote sensors, Caltech researchers on campus and at the Jet Propulsion Laboratory (JPL) are pinpointing sources of methane emissions.

Volcanic activity (seeps or eruptions) releases a lot of CO2, but human activities now produce ~100 times more CO2 than nature. Human methane emissions are roughly equal to emissions from natural sources.

Credit: Meredith Niles for Caltech Science Exchange

How could humans limit emissions?

Read more about these solutions on the Caltech Science Exchange:

Using alternative, or renewable, energy sources such as wind and solar to power cars, houses, businesses
Capturing and storing the emissions before they reach the atmosphere
Developing batteries to efficiently and safely store renewable energy
Designing a power grid that can utilize renewable energy sources instead of fossil fuel
Reimagining industrial chemical processes

Dive Deeper

Looking out of an airplane window

Calculate Your Carbon Footprint

USE THE CALCULATOR ＞

solar_power.width-600

Caltech Energy 10 (CE10) Aims to Develop the Roadmap Toward a 50 Percent Reduction in U.S. Global Warming Gas Emissions by 2030

Sunset on downtown Los Angeles

Natural-Gas Leaks are Important Source of Greenhouse Gas Emissions in Los Angeles