A new study shows that overheated cities facing climate change would cost at least twice as big as the rest of the world. The economic effect discussed in the study is said to be caused by climate change is said to be the "urban heat island" effect.

The study published in Nature Climate Change titled "A global economic assessment of city policies to reduce climate change impacts," was made by an international team of economists of all the world's biggest cities to quantify first the potentially devastating combined impact of global and local climate change on urban economies. The study has analyzed 1,692 cities and it shows that the total economic costs of climate change for cities this century could be over 2.6 times higher when heat island effects are taking into account than when they are not.

Based on their study, the worst-off city losses would reach 10.9 percent of GDP by the end of the century because of climate change. Compared with a global average of 5.6 percent, this is alarming, according to the researchers.

The urban heat island usually occurs when natural surfaces like vegetation and water are replaced by heat-trapping concrete and asphalt and it is exacerbated by heat from cars, air conditioners, etc. This effect caused by climate change is expected to have an additional two degrees to global warming estimates for the biggest cities by 2050 in terms of populations.

In an article published in Science Daily, higher temperatures caused by climate change has damaged the economy in some ways. This is because of the air used for cooling results to air being more polluted, water quality decreasing, and even workers being less productive.

"Any hard-won victories over climate change on a global scale could be wiped out by the effects of uncontrolled urban heat islands," Richard SJ Tol, a professor from the University of Sussex, said. He also said that the study shows that city-level adaptation strategies are used to limit local warming to have important economic net benefits for almost all cities around the world.

The research on the effects of climate change to these populous cities is expected to have important implications for future climate policy decisions. It is clear that we have until now underestimated the dramatic impact that local policies could make in reducing urban warming, Tol said.