Carbon dioxide (CO2) is a greenhouse gas that is emitted naturally through the carbon cycle, and through activities like the burning of fossil fuels (oil, natural gas and coal), solid waste, trees and wood products, and also as a result of other chemical reactions (e.g., manufacture of cement). Carbon dioxide is also removed from the atmosphere (or "sequestered") when it is absorbed by plants as part of the biological carbon cycle.
Since the Industrial Revolution in the 1700s, human activities (e.g. burning of fossil fuels and deforestation) have dramatically increased CO2 concentrations in the atmosphere. High CO2 levels in the atmosphere contribute directly to climate change. In 2005, global atmospheric concentrations of CO2 were 35 percent higher than they were before the Industrial Revolution. (Source: EPA / Photo: Flickr)

Carbon dioxide in Earth's atmosphere has set another ominous record

Why quitting the Paris climate deal is a bad idea

11 alarming facts about sea-level rise

The Pliocene called. It wants its CO2 levels back.

Global CO2 emissions hit record high in 2018, as Greenland ice melt goes into 'overdrive'

Swiss firm gains steam in mission to suck CO2 directly from the air

Scientists amplify mineral's CO2-storing ability

As cities grow, so does the need for urban trees

Don't underestimate the carbon-capturing power of the most basic backyard

Climate change is a 'public health emergency'

Carbon dioxide levels are reaching heights we haven't seen in 800,000 years

Plants may be wising up faster than humans to the dangers of global warming