Climate crisis is a term describing global warming and climate change, and their impacts. This term and the term climate emergency have been used to describe the threat of global warming to humanity and the planet, and to urge aggressive climate change mitigation. In the scientific journal BioScience, a January 2020 article, endorsed by over 11,000 scientists worldwide, stated that "the climate crisis has arrived" and that an "immense increase of scale in endeavors to conserve our biosphere is needed to avoid untold suffering due to the climate crisis." The term is applied by those who "believe it evokes the gravity of the threats the planet faces from continued greenhouse gas emissions and can help spur the kind of political willpower that has long been missing from climate advocacy". They believe that, much as "global warming" drew out more emotional engagement and support for action than "climate change", calling climate change a crisis could have an even stronger impact. A study has shown that the term invokes a strong emotional response in conveying a sense of urgency; some caution that this response may be counter-productive, and may cause a backlash effect due to perceptions of alarmist exaggeration. Scientific basis While powerful language had long been used in advocacy, politics and media, until the late 2010s the scientific community traditionally remained more constrained in its language. However, in a November 2019 statement published in the January 2020 issue of the scientific journal BioScience, a group of over 11,000 scientists argued that describing global warming as a climate emergency or climate crisis was appropriate. The scientists stated that an "immense increase of scale in endeavor" is needed to conserve the biosphere, but noted "profoundly troubling signs" including sustained increases in livestock populations, meat production, tree cover loss, fossil fuel consumption, air transport, and CO2 emissions—concurrent with upward trends in climate impacts such as rising temperatures, global ice melt, and extreme weather, which in turn can also have many indirect impacts such as large-scale migration and food insecurity. Also in November 2019, an article published in Nature concluded that evidence from climate tipping points alone suggests that "we are in a state of planetary emergency", defining emergency as a product of risk and urgency, with both factors judged to be "acute". The Nature article referenced recent IPCC Special Reports (2018, 2019) suggesting individual tipping points could be exceeded with as little as 1–2