Definition: Permafrost degradation refers to the thawing of permanently frozen ground, which can release additional greenhouse gases into the atmosphere.

Example: Observable impacts of climate change include the thinning of Arctic Sea ice by 40% during late summer to early autumn, and a 10% decrease in snow cover areas.

Highlight: The page emphasizes that positive action is possible through simple measures like planting trees, recycling, and reducing fossil fuel consumption.

Quote: "It is easy when thinking about global warming to forget that Earth - over the billions of years of its existence - has experienced a number of extended periods of severe climate change."

Vocabulary: HFCs (Hydrofluorocarbons), PFCs (Perfluorocarbons), and SF6 (Sulfur Hexafluoride) are industrial greenhouse gases contributing to climate change.

Definition: Climate change occurs when the energy balance in the Earth's climate system is altered, affecting all components within it.

Vocabulary: Greenhouse gases are atmospheric gases that trap heat and regulate Earth's temperature, including carbon dioxide, methane, and nitrous oxide.

Example: Without greenhouse gases, Earth's average temperature would be approximately -18 degrees Celsius, demonstrating their crucial role in maintaining habitable conditions.

Highlight: Carbon dioxide levels have increased by approximately 30% since the industrial revolution began, primarily due to fossil fuel combustion.

Quote: "The Earth's climate is always changing. The planet is warmer today than it has been for thousands of years."