Underestanding Tipping Points Caused by Climate Change in Iran: A review

IMAN BABAEIAN , Raheleh Modirian, Maryam Karimian, Leili Khazanedari

Climate tipping points are caused by global warming and refer to critical thresholds in the climate system, crossing which leads to irreversible changes in climate conditions, ecosystems, and even socio-economic structures. These changes may occur over long time scales, ranging from several decades to hundreds of years, and their effects are often negative and threatening, although some positive consequences may also exist. Given the intensity and extent of the impacts of these points, studying and identifying them is essential for better prediction of climate changes and adopting effective adaptation and damage reduction policies. In Iran, multiple negative tipping points due to climate change and global warming have been observed and projected, including the shift of about 90% of the country’s cities to a drier climatic zone under the high greenhouse gas emission scenario of SSP5-8.5, the reduction of snow's share in total precipitation, the increase in the duration of heatwaves from the current 5 days to about two weeks under the low emission scenario of SSP1-2.6 and one season under the high emission scenario of SSP5-8.5, doubling drought vulnerability by the end of the 21st century according to the high emission scenario, the displacement of one-third of Iran’s population over the next 25 years (by 2050) to the northern third of the country, weakening of Caspian Sea precipitation and parts of the northeast due to weakening migratory high-pressure weather systems, making agriculture unprofitable in some provinces including saffron farming, and increasing flood-prone areas and peak discharge of the Shandiz river up to fivefold. On the other hand, positive tipping points have also been observed, such as the increase of tropical cyclones in the northern Indian Ocean and the Arabian Sea and increased extreme precipitation in the southern strip of the country, as well as the replacement of fossil fuels with renewable energy sources. These developments call for special attention to climate risk management and the development of sustainable adaptation policies.