What will happen in a world of 4°C temperature increase by the end of the century as the World Bank warns in their Turn Down the Heat report.
It is impossible to be 100% certain, but what is widely accepted is a temperature increase will have sever climatic consequences.
Extreme heat waves
Heat waves happens from time to time naturally, however, with a 4°C temperature increase heat waves will happen more often and at a more extreme level.
The extreme heat waves will not be evenly distributed across the world.
Sub-tropical Mediterranean, northern Africa, the Middle East, and the contiguous United States are likely to see monthly summer temperatures rise by more than 6°C.
The report warns that by the time the warming levels reach 1.4° C in 2030s, coral reefs may stop growing. This would be a result of oceans becoming more acidic as a result of higher CO2 concentrations. And with 2.4° C, coral reefs in several areas may actually start to dissolve. This is likely to have profound consequences for people who depend on them for food, income, tourism and shoreline protection.
Lower agricultural yields
Extreme heat waves and hotter weather is a real threat for agriculture, which could turn into lower crop yields. Today 15.4% of global cropland is drought-affected and that could increase to 44%. This raises concerns about future food security.
The most severely affected regions will likely be in southern Africa, the United States, southern Europe and Southeast Asia.
Risks to Human Support Systems
The report identifies severe risks related to adverse impacts on water availability, particularly in northern and eastern Africa, the Middle East, and South Asia. River basins like the Ganges and the Nile are particularly vulnerable. In Amazonia, forest fires could as much double by 2050. The world could lose several habitats and species with a 4°C warming.
We are likely to see huge movements of people as changing conditions may force them to see areas less affected. Climate refugees are already existing, but we are likely to see much more of it, which can lead to conflicts over resources.
Island states disappearing
Small island states, like the Maldives, will no longer be able to support its people and coastal cities will disappear due to rising sea levels.
For those interested to explore more on possible consequences of a hotter globe you might want to read Mark Lynas’ book “Six Degrees: Our Future on a Hotter Planet” or watch “Six Degrees Could Change the World”, National Geographic’s film version of the book.