Scientists Say CO2 Levels Went Up In Drought Years Of 2004, 2009 A deficit monsoon not only impacts crops and groundwater level but also has a worrisome impact on the climate. An analysis of two drought years in the last decade has shown an increased level of carbon-dioxide (CO2) over India in the atmosphere, which scientists have attributed to poor rains. The analysis of drought years of 2004 and 2009 has revealed that CO2 concentration over India increased by almost 3ppm (parts per million). Scientists at city-based Indian Institute of Tropical Meteorology (IITM), who carried out the study , also found that between 2004 and 2011, CO2 concentration increased by almost 16 ppm. CO2 is a greenhouse gas which traps heat in the atmosphere, causing the planet's temperature to in crease, thus contributing to global warming. The study, which was undertaken by IITM’s Yogesh K Tiwari, J V Revadekar and K Ravi Kumar, was published in October this year in the international journal Elsevier. “When CO2 is emitted in the atmosphere, it traps heat and gets absorbed in the ocean and vegetation. We have shown that there is a decrease in the all-India Normalized Difference Vegetation Index (NDVI), an indicator of live green vegetation, in all the months of the drought-hit years. Less vegetation will increase CO2 in the atmosphere in the long run and will affect climate system significantly. The 3 ppm increase during a drought year is an indicator of decrease in vegetation during drought years. If this continues, it will significantly affect the climate system,” said Tiwari. In 2004, monsoon arrived early over India as a weak current with a slow northward progress. The du ration of one of monsoon's major rain producing phases in 2004 was short. This phase is called the established phase, which produces approximately two-thirds of the seasonal rain. The all-India average had rainfall picked up only after the third week of July , resulting in a seasonal deficiency of 13%. The drought was severe in the year 2009, when the actual rainfall was around 23% lower than the average rainfall over most parts of India. The seasonal rainfall deficiency in 2014 for India was 12%. “The analysis showed that CO2 over India registered a widespread increase in magnitude and spatial extent during the summer monsoon seasons from 2003 to 2011. In 2003, the average CO2 value was about 375 ppm, which increased up to 391 ppm in 2011. The highest increase of CO2 over India was seen in the year 2009, which was a severe drought year. Though the year 2004 had a deficient monsoon rainfall, it showed the lowest increase in CO2 levels,“ said Tiwari. Tiwari said that summer monsoon is responsible for giving India most of its rainfall share. Widespread rainfall activity causes the vegetation to grow, which controls growth of CO2. This is one of the reasons why the spatial and temporal distribution of CO2 changed or increased during drought years.