Climate change basics

  • Photo: What is climate change?

    What is climate change?

    Most people know climate change has something to do with industrial pollution, changing weather and car exhaust but when asked to explain the planet's health problem in lay terms, the message isn't quite as simple. More »

  • Photo: Greenhouse gases

    Greenhouse gases

    Much like the glass of a greenhouse, gases in our atmosphere sustain life on earth by trapping the sun's heat. The danger lies in the rapid increase of carbon dioxide and other greenhouse gases that intensify this natural greenhouse effect. More »

  • Photo: Carbon offsets

    Carbon offsets

    A "carbon offset" is an emission reduction credit from another organization's project that results in less carbon dioxide or other greenhouse gases in the atmosphere than would otherwise occur. More »

  • Photo: Air travel and climate change

    Air travel and climate change

    Although aviation is a relatively small industry, it has a disproportionately large impact on the climate system. It presently accounts for 4-9% of the total climate change impact of human activity. More »

  • Photo: Forests and sinks

    Forests and sinks

    Forests, soil, oceans, the atmosphere, and fossil fuels are important stores of carbon. Carbon is constantly moving between these different stores, that act as either "sinks" or "sources." More »

  • Photo: Climate change deniers

    Climate change deniers

    The debate is over about whether or not climate change is real. Irrefutable evidence from around the world — including extreme weather events, record temperatures, retreating glaciers, and rising sea levels — all point to the fact climate change is happening now. More »