The Earth's atmosphere is now warming at the fastest rate in recorded history, a trend that is projected to cause extensive damage to forests, marine ecosystems, and agriculture.

Human communities are also threatened by climate change as seas rise, storms become more intense, and episodes of drought and flooding increase.

The scientific evidence is now compelling that recent climate change is caused at least in part by human activities, especially the burning of fossil fuels, which has driven atmospheric carbon dioxide concentrations to their highest levels in 420,000 years.