south asia faces increased double-threat of extreme heat extreme pollution study showsregional study led by texas a&m professor was first of its kind and produced alarming resultsapr 21 2020daily street life in the early morning during extreme smog conditions in new delhi india in 2012 (photo courtesy of istock/getty)scientists know that extreme heat has a negative impact on the human body causing distress in the respiratory and cardiovascular systems and they know that extreme air pollution can also have serious impacts on the human body but as climate change impacts continue globally how often will humans be threatened by both of those extremes when they occur simultaneously a texas a&m university professor has led a regional research study recently published in the brand new journal agu advances answering that question for south asia south asia is a hot-spot for future climate change impacts said dr yangyang xu an assistant professor in the department of atmospheric sciences in the college of geosciences at texas a&m extreme heat occurrences worldwide have increased in recent decades and at the same time many cities are facing severe air pollution problems featuring episodes of high particulate matter (pm) pollution he said this study provides an integrated assessment of human exposure to rare days of both extreme heat and high pm levels our assessment projects that occurrences of heat extremes will increase in frequency by 75% by 2050 that is an increase from 45 days a year to 78 days in a year more concerning is the rare joint events of both extreme heat and extreme pm will increase in frequency by 175% by 2050 xu said climate change is not just a global average number it is something you can feel in your neighborhood he said and thats why regional-scale climate studies are important the studys regional focus was south asia: afghanistan bangladesh bhutan india myanmar nepal and pakistan the scientists used a high-resolution decadal-long model simulation using a state-of-the-science regional chemistry-climate model xu lead the first of its kind research project and scientists from the national center for atmospheric research (ncar) in boulder colorado led the development of the fully coupled chemistry-climate model and performed model simulations for the present-day and future conditions these models allow chemistry and climate to affect each other at every time step said dr rajesh kumar a project scientist at ncar and co-author on the study the study was also co-authored by dr mary barth and dr gerald a meehl both senior scientists at ncar with most of the analysis done by texas a&m atmospheric sciences graduate student xiaokang wumumbai maharashtra india - october 2019: high air pollution and haze envelops the high rises in the suburb of kandivali east (photo courtesy of istock/getty)dr yangyang xuas climate change impacts continue to become reality it is important for scientists to consider human impacts of multiple extreme conditions happening simultaneously xu said projected increases in humidity and temperature are expected to cause extreme heat stress for the people of south asia where the population is projected to increase from 15 billion people to 2 billion by 2050 it is important to extend this analysis on the co-variability of heat and haze extremes in other regions of the world such as the industrial regions of the us europe and east asia barth said the analysis also showed that the fraction of land exposed to prolonged dual-extreme days increases by more than tenfold in 2050 much larger than the increase when assessed individually i think this study raises a lot of important concerns and much more research is needed over other parts of the world on these compounded extremes the risks they pose and their potential human health effects xu said read the full research study in agu advances ncar is sponsored by the national science foundation and managed by the university corporation for atmospheric research by leslie lee '09