start of 2016, with more than 1.5 million cases across more than a dozen countries in the Americas. The World Health Organization warned that Zika had the potential to become an explosive global pandemic if the outbreak was not controlled. Economic consequences In 2016, the commission on a Global Health Risk Framework for the Future estimated that pandemic disease events would cost the global economy over $6 trillion in the 21st century—over $60 billion per year. The same report recommended spending $4.5 billion annually on global prevention and response capabilities to reduce the threat posed by pandemic events, a figure that the World Bank Group raised to $13 billion in a 2019 report. It has been suggested that such costs be paid from a tax on aviation rather than from, e.g., income taxes, given the crucial role of air traffic in transforming local epidemics into pandemics (being the only factor considered in state-of-the-art models of long-range disease transmission ). The COVID-19 pandemic is expected to have a profound negative effect on the global economy, potentially for years to come, with substantial drops in GDP accompanied by increases in unemployment noted around the world. The slowdown of economic activity early in the COVID-19 pandemic had a profound effect on emissions of pollutants and greenhouse gases. The reduction of air pollution, and economic activity associated with it during a pandemic was first documented by Alexander F. More for the Black Death plague pandemic, showing the lowest pollution levels in the last 2000 years occurring during that pandemic, due to its 40 to 60% death rate throughout Eurasia. See also Asian Flu of 1957 Biological hazard Compartmental models in epidemiology Crowdmapping Disease X European Centre for Disease Prevention and Control (ECDC) Hong Kong Flu of 1968 Immunization Mathematical modelling of infectious disease Medieval demography Mortality from infectious diseases Pandemic fatigue Pandemic severity index Public health emergency of international concern Super-spreader Syndemic Tropical disease Timeline of global health Twindemic Vaccination WHO pandemic phases Notes References Further reading Brilliant, Larry, Mark Smolinski, Lisa Danzig, and W. Ian Lipkin, "Inevitable Outbreaks: How to Stop an Age of Spillovers from Becoming an Age of Pandemics", Foreign Affairs, vol. 102, no. 1 (January/February 2023), pp. 126–130, 132–140. Brook, Timothy; et al. "Comparative pandemics: the Tudor–Stuart and Wanli–Chongzhen years of pestilence, 1567–1666" Journal of Global History (2020) 14#3 pp 363–379 emphasis on Chinese history, compared to England Eisenberg, Merle,