By Dr Wolfgang Cramer
Professor, Earth System Analysis, Potsdam Institute for Climate Impact Research, Potsdam, Germany
Apprehensions about climate continue to rise, despite our limited ability to make precise assessments of its impact. This is partially due to the complexity of chemical and physical processes at various scales and also due to confounding factors from other changes such as air pollution.
The combined effects from atmospheric brown clouds (ABC), and of the global increase in greenhouse gas (GHG) concentrations are good examples of complex chemical and physical processes at various scales. ABC block a part of the incoming solar radiation and thereby reduce direct warming effects from GHG. Climate change is an ever more serious issue for South Asia, particularly for the agricultural sector where both warming and reduced water availability may severely harm crop productivity. It is crucial to note that even a small change in climate may result in high social vulnerability of those dependent upon agriculture for their survival because many crops rely on the regular return of monsoon. Moreover, the economic potential to adapt is very low for most Indian farmers. The warming of recent decades (≈ 0.44°C since 1930) has likely affected crop yields through several mechanisms associated with direct temperature as well as changes in...