Climate and culture: abrupt change and rapid response
As the world experiences record heat, increased drought and fires, unprecedented ice melt and similar extreme weather anomalies decades before expected, climatologists have been forced to reconsider previous climate change projections and research techniques. Less than a decade ago, scientific consensus considered warming of more than 2°C (3.6°F) and atmospheric levels of carbon dioxide near 450 parts per million (ppm) as acceptable or "safe". Revised climate science literature and expert opinion now regard safe atmospheric levels of carbon dioxide as below 350 ppm, or less than 1°C (1.8°F) rise in average planetary temperature. Many researchers and environmentalists, however, recognize that the present deviation from pre-industrial temperatures of 0.8°C (1.4°F) may be unacceptable to prevent runaway climate change and widespread disasters.
