The increased inputs of co2 and other green house gases into the atmosphere from human activities will enhance the earth’s natural greenhouse effect of raising the average global temperature of the atmosphere near the earth’s surface. This enhanced green house effect is called GLOBALWARMING.A s a result glaciers melt and thermal expansion of the ocean occurs. A 20cm rise is expected in sea level by 2030.It has a long term negative effect on crop production and forest growth. As climatic pattern shifts rain fall reduced soils are dried out resulting in major drought. Many plants and animals will have problems in adapting. This will influence the mix of species at different locations .Many will be at risk from extinction, whereas more tolerant varieties will thrive. There would be increase in water borne diseases, infectious disease carried by mosquitoes other diseases vectors. The climate change might cause some eco systems to exceed critical thresholds and result in irreversible decline. Measures to check global warming are – reducing use of fossil fuels, implement energy conservation methods, utilize renewable re sources such as wind solar and hydropower, planting more trees, shifting from coal to natural gas, adopting sustainable agriculture, stabilizing population growth, effective removal of co2 from smoke stacks and removing atmosphreric co2 by utilizing photosynthetic algae.