A rising population demands an upgrade to the infrastructure of towns and cities, failing which congestion and traffic jams become unavoidable. The situation is improved with efficient allocation of resources and infrastructure, usually achieved with the help of computer simulations.
पूर्व के कुछ वर्षों में दिल्ली एवं मुंबई के वातावरण में मीथेन के स्तर में वृद्धि इंगित करता छायाचित्र। 
श्रेय: अध्ययन लेखक