NASA recently revealed evidences that the risk of severe rainfall and drought worldwide may happen due to global warming.

The research team demonstrated through a modeling approach the effect of increasing amount of carbon dioxide concentrations on the rainfall types of Earth.

The team showed 14 computer simulations representing the 14 rainfall types worldwide such as those in the equatorial Pacific Ocean and Asian monsoon regions. The simulation showed that all regions will experience heavier rainfalls due to warming caused by an increasing level of carbon dioxide concentrations in the atmosphere changing the entire rainfall system.

William Lau of NASA's Goddard Space Flight Center in Greenbelt, Maryland, lead author of the study, expounded the different scenarios that may possibly happen. Each region may suffer from heavier rain, less moderate rain, or extended drought.

The study forecasts that for every 1 degree Fahrenheit increase on warming, there will be a 3.9 percent increase on heavy rainfall and 1 percent on light rains. Moderate rainfall drops to 1.4 percent.
Tropical zones near the Pacific Ocean and Asian monsoon regions will experience heavier rainfall while those outside may suffer from drought.

Drought may happen both in the Northern and Southern Hemisphere affecting the United States, Mexico, North Africa, the Middle East, Pakistan, China, South Africa, Australia, Central America and Brazil.

The team started with 280 parts per million of carbon dioxide and added 1 percent for each year in the 140-year period of the simulation. The measurement of the carbon dioxide was based on the record of the United Nations' Intergovernmental Panel on Climate Change.

The results were computed based on the rainfall changes during the first 27 years. This period though is a controlled period adding only 1 percent of gas each year. After the controlled period, the team did an uncontrolled period of 27 years randomly increasing the amount of carbon dioxides.