The scientific view is that the increase in global temperature should not exceed 2°C above the pre-industrial level. If the global temperature increases beyond 3°C above the pre-industrial level, what can be its possible impact/impacts on the world? 1. Terrestrial biosphere tends toward a net carbon source. 2. Widespread coral mortality will occur. 3. All the global wetlands will permanently disappear. 4. Cultivation of cereals will not be possible anywhere in the world.