Cirrus cloudCirrus (cloud classification symbol: Ci) is a genus of high cloud made of ice crystals. Cirrus clouds typically appear delicate and wispy with white strands. Cirrus are usually formed when warm, dry air rises, causing water vapor deposition onto rocky or metallic dust particles at high altitudes. Globally, they form anywhere between above sea level, with the higher elevations usually in the tropics and the lower elevations in more polar regions.
Climate emergency declarationA climate emergency declaration or declaring a climate emergency is an action taken by governments and scientists to acknowledge humanity is in a climate crisis. The first such declaration was made by a local government in December 2016. Since then over 2,100 local governments in 39 countries have made climate emergency declarations . Populations covered by jurisdictions that have declared a climate emergency amount to over 1 billion citizens.
Business action on climate changeBusiness action on climate change includes a range of activities relating to climate change, and to influencing political decisions on climate change-related regulation, such as the Kyoto Protocol. Major multinationals have played and to some extent continue to play a significant role in the politics of climate change, especially in the United States, through lobbying of government and funding of climate change deniers.
Hotelling's T-squared distributionIn statistics, particularly in hypothesis testing, the Hotelling's T-squared distribution (T2), proposed by Harold Hotelling, is a multivariate probability distribution that is tightly related to the F-distribution and is most notable for arising as the distribution of a set of sample statistics that are natural generalizations of the statistics underlying the Student's t-distribution. The Hotelling's t-squared statistic (t2) is a generalization of Student's t-statistic that is used in multivariate hypothesis testing.