After the industrial revolution and the rapid growth of industries and increased use of fossil fuels, the amount of green house gases and particularly CO₂ increased in global atmosphere. This causes more absorption of the earth’s infra red radiations by green house gases and therefore increases in world temperature [1]. Nowadays global warming has turned into a global dilemma and has attracted the attention of many world scientists in various disciplines. In 2015 the United Nations Climate Change Conference, held in Paris aimed to achieve a legal binding and universal agreement on slowing down climate change. Leaders of 150 nations, along with 40,000 delegates from 195 countries, attended the 2015 United Nations Climate Change Conference, in order to tackle climate change on a global political level [2]. This paper uses evidence from recently published studies to show a glimpse of the effects of climate change on future human health in Iran. More than 82% of Iran's area is in the arid and semi-arid climate zone and the average annual rainfall is less than 250 mm, which is less than one third of the world average precipitation. The nation’s average temperature varies between -20 and +50°C around the year [3].

If ambient CO₂ continues to rise and reach the predicted 2-fold increase in 2100, Iran's average temperature will increase 1.5 to 4.5 °C [3, 4]. This increase will be higher and more intense in the central and desert zones of Iran but less in the coastal zones of the Caspian Sea in the north and Oman Sea in southeast of Iran [4]. Recent studies have showed that the frequency of hot extreme temperature events has increased in Iran from 1962 to 2004, while a negative trend has been observed in the frequency of cold extreme temperatures. The strongest increasing tendency was detected in the annual number of hot nights, warm nights, warm days, and the heat wave duration indices [5]. Over the last 15 years (1995–2010), the annual frequency of warm days and nights in Iran has increased by 12 and 14 days/decade, respectively. The number of cold days and nights has decreased by 4 and 3 days/decade, respectively. The annual mean maximum and minimum temperature averages across Iran both increased by 0.031 and 0.059 °C/decade. The probability of cold nights has gradually decreased from more than 20 % in 1975–1986 to less than 15 % in 1999–2010, whereas the mean frequency of warm days has increased between the first 12-year period (1975–1986) and the recent 12-year period (1999–2010) from 18 to 40 % respectively.

Global warming by melting arctic ice is causing increased sea levels around the world. As sea water level rises, changes in temperature and precipitation, will lead to decline in fresh water resources, and will further restrain the countries scarce drinking water resources. Sea water level has been rising at an average value of 4.5 mm/year [3]. Sea level rises can impose serious damages in Iran's coast lines. In the north, Iran's main agricultural region, sea level rise will damage agriculture land, shrink forests, and further restrain food production and force people to immigrate from villages to cities [3]. In the south, in the Persian Gulf and Oman Sea, sea water rise can threaten the energy industry, oil installations and exports. The largest exporting ports of Iran are located in the south coastal area. Fresh water resources (both surface water and underground water) will get contaminated and saltwater intrusion will particularly happen in the Karoon River [3]. Climate change will lead to more droughts with more frequency and more intensity despite other areas being stroke by severe rainfall and floods [3]. In the agriculture sector, based on data from 1984-2004, researchers have forecasted that climate change in Iran through increased temperature and decreased rainfall will lead to a 41% decrease in the countries wheat production in the next 100 years [1]. Temperature rise can also lead to rice sterility, reduced formation of tuber bulking in potato and loss of pollen viability in maize. Climate change will have a significant effect on forestry sector and will reduce wood production [3]. Decrease in hydropower production resulting from lower water levels in dams, destruction of coastal and off shore, oil, gas, and petrochemical installations in the southern coastal zones by severe sea storms or hurricanes happening from climate change, [3] can led to more expensive energy. On the other side global warming will increases the energy demand [3] as people will need more air conditioning to keep their houses cool. Studies have indicated that in Iran drought has priority to other natural disasters in the frequency of occurrence, duration, extent, loss of life, economic and social impacts and severe effects in the long run [14]. There is a window of opportunity for avoiding the most damaging effects of climate change, but the window may be closing soon [3]. The Iranian government has taken positive measures for the development of renewable energy sources including solar, wind energy, geothermal waves, tidal energy, hydrogen energy and hydropower and nuclear energy.